Abstract:
A digital camera having an image shake correction apparatus and a method of preventing the image shake of an image taken by the digital camera. The digital camera includes optical elements arranged along a bent line for focusing an object image upon a light receiving plane in which the elements include at least one mirror which reflects a light from an object toward the light receiving plane, a driver for moving the mirror so as to turn its light axis having been bent by the mirror, a vibration sensor for sensing a vibration of a camera body, and a processor for making the driver move the mirror based on the sensed vibration. The mirror turns so as to cancel the vibration of the object image focussed on the light receiving plane.

Description:
This application is based upon application No. 2003-9889 filed in Japan, the contents of which are hereby incorporated by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an image taking device, such as a digital camera, provided with a bent optical system. 
   2. Description of the Related Art 
   When a body of a camera, as an image taking device, is moved by vibration or shaking of hands which hold the body while taking an image of an object (or while exposing), the image thereof formed or focused on an acceptance surface, or on a light receiving surface, moves or shifts with respect to the acceptance surface, so that a captured image, becomes uncleared or blurred. In order to solve this problem, there has been proposed a camera provided with an image shake preventing mechanism, which makes an optical axis thereof deflect so as to counteract a shift of the image focus position with respect to the acceptance surface, when the camera is moved or shaken with respect to the object. 
   As for such an image shake preventing mechanism, there has been proposed one type thereof which translates an image shake preventing lens in parallel with a direction perpendicular to the optical axis as disclosed in, for example, Japanese Non-Examined Laid-Open Patent Publication No. 4-180040. Also, there has been proposed the other type thereof which tilts an incident plane or a reflection plane of a Vari-Angle Prism, as disclosed in, for example, Japanese Non-examined Laid-Open Patent Publication No. 5-11304. 
   On the other hand, there has been provided a camera, an optical axis of which is bent so as to make the camera low-profile and compact. Such a camera has a high sensitivity to an error due to its small construction, or miniaturization, thereof, so that only a small error causes a great influence on the performance thereof. Thus, it is necessary to adjust a deflection or eccentricity of the optical axis accurately. Such an adjustment is, however, difficult. Moreover, the shake of such a low-profile camera tends to be relatively greater. 
   In order to provide the camera with such an image shake preventing function, the aforementioned one type thereof in which the image shake preventing lens is translated in a direction perpendicular to the optical axis, requires a 2-dimensional slide mechanism arranged around an image taking optical system. Therefore, the construction thereof becomes complicated. As for the aforementioned other type thereof, the optical aberration of the Vari-Angle Prism is large, and it is not suitable for a still picture record type of camera which is expected to have a high performance. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is an object of the present invention to provide an image taking device, such as a digital camera, provided with a bending optical system (or a bent optical system), to which an image shake preventing function is added without sacrificing the miniaturization or downsizing thereof. 
   It is another object of the present invention to provide the image taking device having the bending optical system, in which it is easy to adjust a deflection of its optical axis. 
   It is still another object of the present invention to provide a method for preventing an image shake of the image taking device having the bending optical system. 
   In order to achieve these and other objects of the present invention, according to one aspect thereof, there is provided an image taking device for taking an image of an object, comprising: a bending optical system (or a bent optical system) for forming or focusing the image thereof on an acceptance surface (or a light receiving surface), in which the bending optical system includes at least one optical bending member which bends an optical axis of the bending optical system from the object to the acceptance surface; a driving mechanism for driving the at least one optical bending member so as to change angle of the optical axis having been bent by the at least one optical bending member; a shake detector for detecting a shake of a body of the image taking device; and a controller for controlling the driving mechanism on a basis of the shake of the body of the image taking device detected by the shake detector, so that the at least one optical bending member is driven by the driving mechanism so as to cancel or counteract the shake or movement of the image of the object formed on the acceptance surface. 
   In the construction, there is arranged an image sensor or a silver halide film for example, on the acceptance surface, at the position where the bending optical system focuses the image of the object. 
   According to the construction, the shake detector detects the shake or movement of the body of the image taking device. The shake detected by the shake detector includes not only the change of angle of the body, but also the movement thereof. Based upon the shake thus detected, the driving mechanism drives the at least one optical bending member so that the at least one optical bending member changes the angle of the optical axis of the bending optical system in order to restrict any deviation of the position of the image focused on the acceptance surface within an allowable range. Thereby, a clear image of the object having no image shake can be taken or captured, even if the body of the image taking device is moved due to a shake of the user&#39;s hands holding the body. The driving mechanism is not necessary to be arranged all around the bending optical system, but the driving mechanism can be arranged on one side only relative to the bending optical system. 
   With the construction, there is provided the image taking device having the bent optical system, to which the image shake preventing function is added without sacrificing the miniaturization or downsizing thereof. 
   Preferably, the at least one optical bending member is supported pivotally about one point, and the driving mechanism drives the at least one optical bending member so as to change the angle of the at least one optical bending member. 
   The “one point” can be substantially or generally one point; therefore, the “one point” includes such a point as having an area. 
   The above construction is simple and is easy to be downsized, comparing with a construction in which the optical bending member translates parallel. Especially, the above construction is suitable for a digital camera, as the image taking device, which requires to be made low-profile and compact. 
   Preferably, the driving mechanism includes an actuator using a piezoelectric element. 
   The actuator using the piezoelectric element is suitable for the driving mechanism, because it has a high response performance and is easy to be miniaturized. 
   Preferably, the at least one optical bending member driven by the driving mechanism is a mirror. 
   According to the construction, a reflection surface of the mirror bends the optical axis of the bending optical system. The mirror is lighter than a prism, and a space where the mirror is arranged is smaller than that where the prism is arranged. In a case of the prism, movement of a reflection surface thereof causes an input surface thereof and an output surface thereof also to move. The mirror, however, does not cause such a complicated movement. 
   Alternatively, the at least one optical bending member driven by the driving mechanism can be a prism. 
   Preferably, at least one of the optical bending members, which are driven by the driving mechanism, has a reflection surface, which bends the optical axis of the bending optical system. Behind the reflection surface, or in a space opposite to a side of the optical axis with respect to the reflection surface, there are arranged main parts, or components, of a mechanism for realizing the prevention (or compensation or correction) of the image shake. The main parts thereof include parts constituting at least the driving mechanism, and more preferably, the main parts further include the shake detector. 
   Namely, preferably, the driving mechanism is arranged behind the at least one optical bending member, and/or the shake detector is arranged behind the at least one optical bending member. 
   According to such a construction, the space behind the reflection surface can be used effectively so as to reduce the size of the body. 
   Preferably, the driving mechanism drives the at least one optical bending member so as to adjust a deflection of the optical axis of the bending optical system. 
   According to the construction, it is possible to adjust the deflection of the optical axis of the bending optical system, or to change the amount of adjustment based on the change in properties with time, the change in temperature, the change in focal length, and so on. 
   That is, with the construction, it is easy to adjust the deflection of the optical axis. 
   Preferably, the at least one optical bending member driven by the driving mechanism and the driving mechanism are mounted on a moving unit, and the moving unit is movably mounted by a position adjuster. 
   In the construction, the position adjuster adjusts the location, or position, of the moving unit so as to adjust the deflection of the optical axis of the bending optical system. With the construction, it is possible to adjust the deflection of the optical axis thereof precisely, or possible to change the amount of adjustment based on the change of properties with time, the change of temperature, the change of focal length, and so on, by the driving mechanism. 
   Accordingly, it is easy to adjust the deflection of the optical axis. 
   The construction, in which the at least one optical bending member of the bending optical system is driven so as to prevent (or compensate or correct) the shake of image of an object, can be applied not only to a digital camera, but also binocular glasses, and so on. 
   In order to achieve the above objects, according to another aspect of the present invention, there is provided a method for preventing an image of an object taken by an image taking device from shaking, in which the image taking device comprises a bending optical system for forming or focusing the image thereof on an acceptance surface (or a light receiving surface), and in which the bending optical system includes at least one optical bending member which bends an optical axis of the bending optical system from the object to the acceptance surface, the method comprising: a shake detecting step of detecting a shake of a body of the image taking device; and a controlling step of controlling to drive the at least one optical bending member on the basis of the shake of the body detected at the shake detecting step so that the shake of the image of the object focused or formed on the acceptance surface is cancelled or counteracted. 
   In the method, preferably, the controlling step of controlling to drive the at least one optical bending member includes a driving step of driving the at least one optical bending member so as to change angle of the at least one optical bending member. 
   In the method, preferably, it further comprises an adjusting step of driving the at least one optical bending member so as to adjust a deflection of the optical axis of the bending optical system. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other objects and features of the present invention will become clear from the following description taken in conjunction with a preferred embodiment thereof with reference to the accompanying drawings. 
       FIG. 1  is a front elevation view of a digital camera, as an image taking devise, according to a preferred embodiment of the present invention. 
       FIG. 2  is a rear perspective view thereof. 
       FIG. 3  is a schematic block diagram thereof. 
       FIG. 4  is a sectional view showing a constitution of a bent optical unit thereof. 
       FIGS. 5A and 5B  are schematic illustrations of an image shake preventing mechanism thereof. 
       FIG. 6  is a schematic block diagram of the image shake preventing mechanism thereof. 
       FIGS. 7A ,  7 B and  7 C are schematic illustrations of the image shake preventing mechanism thereof. 
       FIGS. 8A and 8B  are schematic illustrations showing how to adjust the deflection of the optical axis of a bent optical system of the bent optical unit. 
       FIG. 9A  is a schematic illustration of a position detecting mechanism of a mirror. 
       FIG. 9B  is a schematic illustration of a position detecting mechanism according to a modification to  FIG. 9A . 
       FIGS. 10A ,  10 B and  10 C are enlarged views showing a drive mechanism for driving the mirror. 
       FIG. 11  is a perspective view of a bent optical system according to a modification to the preferred embodiment. 
       FIGS. 12A and 12B  are perspective projection views of the digital camera having the bent optical system as shown in  FIG. 11 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Before the description of a preferred embodiment of the present invention proceeds, it is to be noted that like or corresponding parts are designated by like reference numerals or characters throughout the accompanying drawings. 
   A detailed description is made below upon a digital camera  10 , as an image taking device, of the embodiment, with reference to  FIG. 1  through  FIG. 12B . 
   Each of  FIGS. 1 and 2  shows an appearance of the digital camera  10 . 
   As shown in  FIG. 1 , on a front surface of a camera body  12 , there are arranged: a flash device  14  for emitting flash light in order to illuminate a photographic subject or object when it is dark; a photometry sensor  15  for detecting an object&#39;s brightness in order to determine an optimal condition of exposure; a finder object aperture  16  of an optical finder; and a lens opening  18  for leading a light from the subject to an image sensor (for example, CCD) through an image taking optical system. 
     FIG. 2  is a rear perspective view showing a backside of the digital camera  10 . 
   A shutter start button (hereinafter, also referred to as “shutter button”)  20  and a main switch  22  are arranged on the upper surface of the camera body  12 . The shutter button  20  is an operation button for capturing an image with the digital camera  10 . The main switch  22  is a power switch of the digital camera  10 . 
   Three of the image capturing state can be set by the operation of the shutter button  20 . That is, when there is no operation of the shutter button  20 , an “OFF state” or a standby state is set. By half-pressing of the shutter button  20 , a “preparation state”, in which a S 1  switch is turned “ON”, is set. By full-pressing of the shutter button  20 , a “start state”, in which a S 2  switch is turned “ON”, is set. 
   On a rear surface of the camera body  12 , there are arranged: a finder eyepiece window  30  for checking an object&#39;s condition through the optical finder; a focus lamp  31  which is arranged on the right side of the finder eyepiece window  30  and which displays a focusing state and so on; a zoom lever  32 ; a right-and-left key  33 ; a selector switch  34  for switching the modes (for example, recorded image reproducing display mode, image capturing mode, moving image capturing mode, etc.) of the camera  10 ; a display  36  (including, for example, a color liquid crystal panel) which displays a live view image, an image being recorded and so on; and a mode button set  38  of mode buttons  38   a - 38   d . The mode button  38   d  is an image shake preventing ON/OFF button. 
   The zoom lever  32  and the right-and-left key  33  are used in the image capturing mode or in a reproducing mode. In the image capturing mode, the focal length of a taking lens can be changed by moving the zoom lever  32  up and down, and an exposure of captured image can be adjusted by pressing the right-and-left key  33 . In the reproducing mode, the zoom lever  32  and the right-and-left key  33  operate as a switch for selecting items shown in the display device  36 . Specifically, operation of the zoom lever  32  and the right-and-left key  33  with reference to a display of the display device  36  can change a flash luminescence state, an image-processing mode of the camera, an image size to be recorded, and a compression level of the recorded image and so on. 
   A lid  13  is arranged on a side of the camera body  12 . By opening the lid  13 , a battery and a memory card, which are not illustrated, can be set or removed therethrough. It is realized to reduce the thickness of the digital camera  10 , by making the single lid  13  function as a lid for the battery and for the memory card. 
   Next, it is explained about a system of the digital camera  10 , referring to  FIG. 3 . 
   The image taking optical system  40  having a taking lens, leads or guides an object image to the image sensor  42  (for example, CCD). The image sensor  42  carries out photoelectric transducing operation, and it outputs a data of the object. The data from the image sensor  42  is send to a digital image processing part  44 . The digital image processing part  44  processes black level correction, color pixel interpolation processing, exposure correction, gamma control, contrast correction, sharpness correction, resolution conversion, image compression, and the like, which are required for digital image processing. The digital image processing part  44  outputs the processed data to the display device  36  and a memory  48 . The display device  36  displays a live view image, an image recorded on the memory  48 , and a camera state. A memory  48 , for example, a removable flash memory card, records photography picture data. 
   A sequence control microcomputer  60  carries out a sequence system processing operation of the digital camera  10 . The sequence control microcomputer  60  includes an exposure control part  62 , a sequence control part  64 , an operation detection part  66 , a zoom control part  68 , and a focus control part  69 . The operation detection part  66  detects the states of various operation switches  34 ,  20 ,  34 ,  38   a - 38   c  and  38   d , and it transmits them to the sequence control part  64 . The sequence control part  64  controls the sequence (or state of operation) of the digital camera  10  based on the state of various operation switches  34 ,  20 ,  34 ,  38   a - 38   c ,  38   d , and so on. The exposure control part  62  determines the exposure state of the camera  10  based on an output of the photometry sensor  15 , and it controls the exposure time of the image sensor  42  and opening-and-closing state of a shutter. The zoom control part  68  changes the focal length of the taking lens (or photographing lens), responding to the operation of the zoom lever  34 . The focus control part  69  detects the state of contrast of the image captured with the image sensor  42 , determines the optimal focal position, and drives a focus lens of the taking lens. 
   An image shake preventing part  50  carries out image shake preventing operation, responding to a command from the sequence control part  64 . 
   On the basis of the control of the sequence control microcomputer  60 , the camera  10  operates generally as follows. After half-pressing of the shutter button  20 , a live view is displayed on the display device  36 , until changing to a sleep state by auto-power-off (normally, for example, about 30 seconds). By the half-pressing of the shutter button  20 , the photometry sensor  15  starts to be operated and an exposure control value is determined. Additionally, a focusing position to be adjusted is detected. At this time, the image shake preventing operation is carried out, if the image shake preventing ON/OFF button  38   d  is in the “ON” state. When it is detected that the shutter button  20  is pressed fully or completely, an image of the object is taken by the image sensor  42 , and it is recorded on the memory  48 . At this time, the image shake preventing operation is carried out, if the image shake preventing ON/OFF button  38   d  is in the “ON” state. 
   Next, it is explained about the image shake prevention of the digital camera, referring to  FIGS. 4 ,  5 , and  8 - 10 . 
   The occurrence of the image shake of an object upon taking an image thereof with the camera is caused by a vibration derived from a combination of: vibration having about 10 Hz with a small amplitude, caused by vibration of man&#39;s muscles; vibration having 3 Hz or less with a large amplitude, caused by the shake of man&#39;s body; and vibration having about 5 Hz, caused by pressing the shutter button  20  (or an image capturing switch) upon shooting. The construction, or mechanism, for preventing such an image shake of an object is shown in  FIGS. 4 ,  5 A,  5 B,  9 A,  9 B,  10 A and  10 B. 
     FIG. 4  shows the bent optical unit which includes the image taking optical system  40  built in the camera body  12  of the digital camera  10 . The image taking optical system  40  is the one which bends its optical axis into forming optical axes A and B. More specifically, the light coming into the system through the lens opening  18  of the camera body  12  is reflected toward the image sensor  42 , which is shown at a lower part of  FIG. 4 , at a generally right angle by a mirror  41 . 
   As a modification, instead of the mirror  41 , another component such as a prism can be used to bend or reflect the light. 
   Upon capturing the image of an object, if the camera body  12  is shaked or vibrated by a shake or vibration of the user holding the camera body  12 , the light path for leading the light from the object to the acceptance surface of the image sensor  42  changes, and thereby the object image moves and overlaps with respect to the acceptance surface thereof, so that an indistinct blurred image is captured. In order to prevent such an image shake, the image of the object must be focused at the same position with respect to the acceptance surface of the image sensor  42  during the image taking. That is, the light path must be rectified, or corrected (or compensated), so as to counteract the shake of the camera  10 , by means of detecting the shake thereof. 
   Each of  FIGS. 5A and 5B  shows a mechanism for preventing such an image shake. 
   In a camera cone unit  11 , the image taking optical system  40 , the image sensor  42 , and the image shake preventing part  50  are arranged. The image taking optical system  40  includes a plurality of lenses L 1 -L 6  and the mirror  41 , so that an image of the object is focused onto the acceptance surface of the image sensor  42 . The mirror  41  bends the optical axis A into the optical axis B in the image taking optical system  40  generally at a right angle, or perpendicularly. 
   A back of the mirror  41  is supported by a mirror base  51 . The image shake preventing part  50  drives the mirror  41  so as to change the angle of the mirror  41  with respect to the mirror base  51 . The image shake preventing part  50  is arranged in an empty space behind the mirror  41  in order to make full use of the empty space. Thereby, the camera body can be downsized or miniaturized. 
   Specifically, as shown in  FIGS. 10A ,  10 B and  10 C, the mirror  41  is supported pivotally by one single point, substantially or generally, of a raised portion  59  mounted on the mirror base  51 . A pair of actuators  57  and  58 , which drive the mirror  41 , are mounted on the mirror base  51 . In the figures, a straight line “S” connects the actuator  57  and the raised portion  59 , and a straight line “T” connects the actuator  58  and the raised portion  59 . The straight lines “S” and “T” intersect at the general one point of the raised portion  59 . The mirror  41  is rotated by one actuator  57  around the straight line “T” which connects the raised portion  59  and the other actuator  58 . Meanwhile, the mirror  41  is rotated around the straight line “S” which connects the raised portion  59  and the one actuator  57 . 
   The raised portion  59  may be made, for example, of rubber having proper hardness, and fixed on both of the mirror base  51  and the mirror  41  with an adhesive. Each of the actuators  57  and  58  is, for example, of a laminating type of piezoelectric elements. As for each of the actuators  57  and  58 , both ends thereof in a direction in which each of the actuators  57  and  58  expands and contracts are fixed to the mirror  41  and the mirror base  51 , respectively. Applying a voltage to each of the actuators  57  and  58 , changes the distance between the mirror  41  and the mirror base  51 , so that the angle of the mirror  41  changes relative to the mirror base  51  (therefore, relative to the acceptance surface of the image sensor  42 ). 
   As shown in  FIGS. 5A and 5B , a pair of shake sensing gyroscopes  55  and  56  are mounted in a space behind the mirror base  51 , or in the side opposite to the optical axes A and B. The shake sensing gyroscopes  55  and  56  detect the shake of the camera body  12 . One shake sensing gyroscope  55  detects any shake in a pitch direction, or in a direction of vertical rotation around a line perpendicular to a drawing plane of  FIG. 5A . The actuator  57  is driven on the basis of the output of the shake sensing gyroscope  55 , so that the mirror  41  is rotated in the pitch direction designated by an arrow  90 . On the other hand, the other shake sensing gyroscope  56  detects any shake in a yaw direction, or in a direction of horizontal rotation (or lateral rotation) around a vertical line parallel to the drawing plane of  FIG. 5A . The actuator  58  is driven on the basis of the output of the shake sensing gyroscope  56 , so that the mirror  41  is rotated in the yaw direction. 
   The mirror  41  is driven with reference to the mirror base  51 . The mirror base  51  is fixed to the housing of the camera cone unit  11  through adjustment members  54   a  and  54   b . Fixing position of the mirror base  51  can be adjusted by the adjustment members  54   a  and  54   b , so that a deflection (or alignment) of the optical axis of the bent optical system  40  can be adjusted. 
   The angle of the mirror  41  is detected by a pair of position sensors  52  and  53 . When the mirror  41  is driven by the piezoelectric actuators  57  and  58  directly as mentioned above, each of the driving amounts of the actuators  57  and  58  is generally proportional to a voltage applied thereto, respectively. Therefore, it is preferable that a position of the mirror  41  is detected by the position sensors  52  and  53 , or by the image sensor  42 , and that the voltage applied to each of the piezoelectric elements is compensated or corrected by feedback of the position of the mirror  41 . If compensation of temperature environment etc. is possible, one or both of the position sensors  52  and  53  can be eliminated or omitted. 
   Specifically, the position sensors  52  and  53  are constructed as shown in  FIGS. 9A and 9B . 
     FIG. 9A  schematically shows a construction, in which a PSD (Position Sensitive Detector) type of position sensor is employed for each of the position sensors  52  and  53 . A mask member  100  and a small chip IRED (infrared ray emitting diode)  110  are fixed to the mirror  41 . The mask member  100  has an opening hole  102 , through which a beam of light emitted by the luminescence chip  112  of the small chip IRED  110  is narrowed down. A one-dimensional PSD (Position Sensitive Detector)  120  for detecting a one-dimensional position is arranged opposite the opening hole  102  of the mask member  100 , and it is fixed to a housing of the camera cone unit  11 , so that the beam of light  180  passing through the opening hole  102  is received by an acceptance unit (or light receiving unit)  122  of the PSD  120 . The acceptance unit  122  has a plurality of acceptance elements (or light receiving elements) which detect light and which are arranged in a line. The PSD  120  outputs the optical current from both ends thereof. The ratio of the optical currents changes depending on the position of weighted center of light received by the acceptance elements of the acceptance unit  122  of the PSD  120 . Accordingly, based on such a ratio of the outputs of the optical currents, the displacement of the mirror  41 , the direction of which is the same as that of the line of the acceptance elements in the acceptance unit  122 , can be detected. 
     FIG. 9B  schematically shows a construction according to a modification to  FIG. 9A , in which a PI (photo-interrupter) type of position sensor is employed for each of the position sensors  52  and  53 . A light blocking member  230  is fixed to the mirror  41 . A PI (photo-interrupter)  200  is fixed near to an end of the light blocking member  230 . The PI  200  has a light emitting part  210  and a light receiving part  220 , between which the end of the light blocking member  230  is inserted. The light emitting part  210  emits a generally parallel beam of light  240  toward the light receiving part  220  as a light acceptance unit. The end of the light blocking member  230  blocks part of the beam of light  240 . When the mirror  41  moves in a direction designated by an arrow  290 , the amount of light blocked by the end of the light blocking member  230  changes, so that an output of the PI  200  changes depending on the amount of light received by the light acceptance unit  220 . Thus, the position of the mirror  41  can be detected, by comparing the output of the PI  200  when the end of the light blocking member  230  blocks none of the beam of light emitted by the light emitting part  210  with the output threof when the end of the light blocking member  230  blocks the beam of light thereof. Using signals of the PI  200  in analog allows the position sensor to be micro-miniaturized. 
     FIG. 6  is a system configuration figure of the image shake preventing part  50  for realizing the compensation, or correction, of the image shake. 
   A drive circuit  70  which drives the image shake preventing mechanism  74 , a shake sensing circuit  78  of an image shake detection system  76 , and a temperature sensor  72 , are connected to an image shake preventing microcomputer  80  which carries out the image shake preventing control, and which communicates with the sequence control microcomputer  60 . 
   Hereinafter, it is explained about a gyroscope (angular-velocity sensor) detection system, an image shake preventing (or compensation or correction) optical system with a reflection mirror rotating system, and a (digital) servo-control system with direct drive system in which a voltage is applied to a laminating type of piezoelectric elements to be driven and with position sensors. 
   If a camera is shaken during image taking, an image focused on an imaging surface (or on a surface of an image taking element) moves so that the captured image becomes blurred. It is possible to prevent such an image shake by the detecting system detecting amount and direction of the shake, and by the correcting optical system bending a light from an object in a direction in which the movement of the image with respect to the imaging surface is counteracted. The camera shakes at about 10 Hz of sine waves at maximum. In order to prevent (or compensate or correct) such as image shake, the correction optical system is driven so as to counteract such waves. 
   The shake sensing gyroscopes  55  and  56  of the image shake detection system  76  are gyroscope sensors for detecting the shake of the camera body  12 . The gyroscopes  55  and  56  detect the angular-velocity of rotation caused by the shake of the camera body  12 . Each thereof detects rotation in one direction, respectively. Thus, one gyroscope  55  detects a shaking of the rotation in the direction of P (pitch). The other gyroscope  56  detects a shaking of the rotation in the direction of Y (yaw). 
   The shake sensing circuit  78  of the image shake detection system  76  is provided with: a filter circuit (a low pass filter and a high pass filter) for cutting noise and drift of the signal from the gyroscopes  55  and  56 ; and an integration circuit for changing a signal of the angular velocity into a signal of an angle, and so on. 
   A block of the image shake preventing microcomputer  80 , which is an image shake preventing control part, is a digital processing part by the microcomputer. The image shake amount detecting part  84  detects the rotations of the P and Y directions outputted from the shake sensing circuit  78  for a predetermined time, and it outputs an amount of rotation of a camera. A sequence control part  86  for compensating image shake, controls an image shake compensation sequence, responding to a signal from the camera sequence control microcomputer  60 . The drive control part  82  determines a target position to drive, based on the output of shake from the image shake amount detecting part  84 . At this time, the target position is rectified with respect to the quantity which changes depending to the temperature, by using the output of the temperature sensor  72 . By detecting a present position signal outputted from the drive circuit part  70  and by comparing it with the target position, an optimal control value (in this case, a value of voltage applied to the actuators) is determined, and it outputs to the drive circuit  70 . 
   The temperature sensor  72  is used in order to rectify, or compensate, a change in performance by temperature. In order to realize an optimal compensation under an operating temperature condition, the change in temperature of the shake compensating optical system and the position sensor, is rectified. When necessary, the drive voltage of the actuator and other parameters are rectified. 
   The drive-system circuit part  70  is provided with: a drive circuit part which applies a voltage corresponding to a result calculated by the drive control part  82  to actuators  56  and  58 ; and a position sensor circuit part which converts a signal from each of the position sensors  52  and  53  of P and Y directions to a voltage value. 
   In the image shake preventing mechanism  74 , the light from an object is reflected by the mirror  41 . When each of actuators  57  and  58  drives the mirror  41 , the light from the object is reflected by the mirror  41  in its respective direction. As a result, the image shake is corrected. 
   The aforementioned one actuator (or P-drive actuator)  57  is an actuator for driving the mirror  41  in the pitch direction. In this embodiment, the direct-drive system, which uses the laminating type piezoelectric element, is employed for the P-drive actuator  57 . 
   The aforementioned one position sensor (or P-direction position sensor)  52  is a position sensor for detecting a motion, or movement, in the pitch direction of the mirror  41 . In the embodiment, an IRED (infrared ray emitting diode) and a slit are provided on a movable side thereof, and a PSD is provided on the fixed side thereof. 
   The aforementioned other actuator (or Y-drive actuator)  58  is an actuator for driving the mirror  41  in the yaw direction. The piezoelectric element direct drive system is employed for the Y-drive actuator  58 , as well as the P-drive actuator  56 . 
   The aforementioned Y-direction position sensor  53  is a position sensor for detecting a motion, or movement, in the yaw direction of the mirror  41 . In the embodiment, an IRED and a slit are provided on a movable side thereof, and a PSD is provided on the fixed side thereof, as well as the P-direction position sensor  52 . 
   Next, it is explained about an operation to compensate or correct the image shake, referring to  FIGS. 7A ,  7 B, and  7 C. 
     FIGS. 7A ,  7 B and  7 C illustrate an image shake compensating (or correcting) principle of the pitch direction in detail. By controlling a voltage applied to the piezoelectric element  57 , length or displacement thereof is changed. Thus, the mirror  41  rotates in the pitch direction around a center support part (i.e. about the line “T” in  FIG. 10B ). 
     FIG. 7A  shows a case where no voltage is applied to the piezoelectric element of the p-drive actuator  57 . 
     FIG. 7B  shows a case where a positive voltage is applied to the piezoelectric element  57  so that the piezoelectric element of the p-drive actuator  57  extends. Thereby, the mirror  41  rotates in a direction designated by an arrow P 1  (or in a clockwise direction in  FIG. 7B ), so that the optical axis B 1  moves ahead or forward, with respect to a standard condition, or position, as shown by B 0 . 
     FIG. 7C  shows a case where a negative voltage is applied to the piezoelectric element of the p-drive actuator  57 , so that the piezoelectric element of the actuator  57  refracts or shrinks. Thereby, the mirror  41  rotates in the other direction designated by an arrow P 2  (or in a counterclockwise direction in  FIG. 7C ), so that the optical axis B 2  moves backward or rearward, with respect to the standard condition, or position, as shown by B 0 . 
   Relation between a rotational angle through which the mirror  41  is driven to rotate and an angle in which the camera body  12  is shaken, is shown by an equation below:
 
θ M =θ C   /P   L1   (1)
 
In the equation, “θ M ” is a rotational angle of the mirror  41 , “θ c ” is a rotational angle caused by shake of the camera body  12 , and “P L1 ” is a power of the lens L 1 .
 
   It is desirable to employ the lens L 1  having a strong (or great) power, in order to realize the compensation of the image shake with a small displacement of the piezoelectric element. On the contrary, it is desirable to employ the lens L 1  having a weak (or small) power, in order to miniaturize the image taking lens. In this case, an actuator having a large displacement (for example, an impact actuator employing a piezoelectric element, a bimorph actuator employing a piezoelectric element, and the like) can be employed for the actuator. 
   The relation between the rotating amount of the mirror  41  and the moving amount of the image focused on the acceptance surface of the image sensor  62  changes, depending on its zoom position and its focal position. Therefore, it is desirable to rectify (or compensate) the rotation amount of the mirror  41  for driving it, based on the condition or state of the digital camera  10 . 
   Next, it is explained about an adjustment of the deflection of the optical axis, referring to  FIGS. 8A and 8B . In order to adjust the deflection of the optical axis, the aforementioned pair of adjustment members  54   a  and  54   b  with which the camera cone unit  11  is provided, are moved for the adjustment so that the mirror  41  is moved or shifted with respect to a housing of the camera cone unit  11 . For example, screws, members made of heat hardening resin, and so on, are employed for the adjustment members  54   a  and  54   b . The deflection of the optical axis is adjusted before shipment from factory. 
   For example, as shown in  FIG. 8B , the adjustment member  54   a  can move in a direction as shown by an arrow  91 . When the member  54   a  is a screw, it is rotated to realize the movement. Thereby, the mirror  41  is rotated in a direction designated by an arrow  92  so that the angle of the mirror  41  is changed. In such an adjustment, there is no need of driving the piezoelectric element. 
   On the other hand, in case that the piezoelectric element is driven not only for correcting the image shake, but also for adjusting the deflection of the optical axis, it is possible to prevent a camera body from becoming large, even if the optical axis deflection adjustment mechanism is provided. That is, the piezoelectric element for compensating the image shake is used to move the mirror  41  so that the optical axis locates at a predetermined position. In this arrangement, an image is captured under a condition of applying a voltage to the piezoelectric element so as to move it to the predetermined position. 
   Alternatively, it is possible to perform a general adjustment thereof by employing the adjustment mechanism as shown in  FIG. 8 , and to perform a precise adjustment by using the image shake compensating mechanism. 
   As explained above, the bent optical system in which the deflection of the optical axis is adjustable, is useful to make the camera body low-profile and compact. With the arrangement, the mirror drive mechanism for correcting the image shake becomes simple, and thus the digital camera can be miniaturized. In addition, with the arrangement, the optical system employed exclusively for correcting the image shake, such as an afocal lens, becomes unnecessary. 
   Moreover, with the arrangement, it is possible to combine an optical axis deflection adjustment function with the image shake correction function, or it is possible to adopt the optical axis deflection adjustment mechanism for an additional precise adjustment, which is difficult by using the optical axis deflection adjustment mechanism. 
   Although the present invention has been fully described in connection with the preferred embodiment thereof with reference to the accompanying drawings, it is to be noted that various other changes and modifications are also apparent to those skilled in the art. 
   For example, the mirror can be driven by any proper actuator (for example, impact actuator employing a piezoelectric element). Moreover, the mirror is not limited to the mirror which is supported by a single point substantially or generally and which is driven in two directions around the single point. For example, the mirror may be supported by three or more piezoelectric elements, without a raised portion for supporting the mirror (i.e. without a support projection for the mirror). 
   Parallel translation of the mirror in a direction perpendicular to a reflective surface of the mirror and angle change of the mirror in a plane including the bent optical axis, can be combined. Moreover, instead of the mirror, for example, a triangular prism can be used to bend the optical axis thereof. In this arrangement, the prism is moved to compensate or correct the image shake. 
   Moreover, the bent optical system  60  having two optically bent components (or mirrors) as shown in  FIG. 11 , can be used. As shown in  FIGS. 12A and 12B , the digital camera provided with the bent optical system  60  can rectify or correct the deflection of the optical axis in the pitch direction by moving a mirror  61 , and the deflection thereof in the yaw direction by moving a second mirror  62 . Each of the mirrors  61  and  62  is pivotally supported at a center thereof, as shown in  FIGS. 12A and 12B . Each of the mirrors  61  and  62  is driven by an actuator  57 . The method of detecting any shake of rotation of the camera body by a gyroscope and of controlling the drive of the actuator, is the same as that of the aforementioned embodiment.