JP3671915B2 - camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a camera having a function of taking an image while correcting camera shake.
[0002]
[Prior art]
In recent years, a camera shake correction function has been provided to a camera in order to prevent a shake of a user holding the camera from appearing in a photographed image. Image stabilization is performed by displacing a part of the photographic optical system that forms an image of light from the subject in a direction perpendicular to the optical axis. In digital cameras and video cameras, light from the photographic optical system is used. This is also performed by displacing an image sensor that performs photoelectric conversion in a direction perpendicular to the optical axis of the imaging optical system.
[0003]
The camera shake correction is for preventing the quality of a captured image from being deteriorated. Therefore, the camera shake correction is performed only when the image is captured, and is not performed when the recorded image is reproduced and displayed. There is also a camera in which a user can arbitrarily select whether to perform camera shake correction when shooting an image by setting a shooting mode in which camera shake correction is performed and a shooting mode in which camera shake correction is not performed. Digital cameras that shoot images for recording in response to user instructions should not perform camera shake correction when shooting images other than images for recording, but only perform camera shake correction when shooting images for recording. Some have done.
[0004]
It has been proposed to use a moving coil as an actuator for displacing a camera shake correction member. While this method has the advantage of being easy to control, a separate locking mechanism is required to hold the correction member in a predetermined position when no camera shake correction is performed. For this reason, the configuration becomes complicated, and there is a great restriction on the miniaturization of the camera. Although it is possible to hold the correction member in a predetermined position by the moving coil itself, it always consumes electric power and is not suitable for a camera using a battery as a power source.
[0005]
Some actuators that use frictional force are used as actuators for displacing a camera shake correction member. In this method, the correction member and the actuator are slidably engaged so that the correction member can only follow the low-speed displacement of the actuator. The correction member is displaced by repeating the high-speed displacement to. The actuator can not only displace the correction member but also hold the correction member at a position after the displacement. Therefore, a lock mechanism is unnecessary and there are few restrictions on miniaturization of the camera. In addition, there is no power consumption when camera shake correction is not performed.
[0006]
However, in the method in which the camera shake correction member is displaced by the frictional force, it is necessary to set the frictional force between the correction member and the actuator within an appropriate range. When an impact exceeding this range is applied to the camera, The member is displaced. During the period when the user is holding the camera and shooting, such a large impact is unlikely to occur, and even if a large impact occurs during shooting, it is handled as a hand shake, so there is no problem. . However, when the shooting is not performed, for example, when the camera is placed on a desk, the impact is large, and when the correction member is displaced, the camera shake correction in the next shooting is adversely affected.
[0007]
Since camera shake occurs in the up / down (vertical) direction and left / right (horizontal) direction, the image stabilization member can be displaced in either the up / down direction or left / right direction, but in either the up / down direction or the left / right direction It is difficult to predict whether camera shake will occur. In addition, there is a limit to the amount by which the correction member can be displaced. For this reason, during a period when shooting is not performed, the camera shake correction member is set at an initial position determined at the center within a displaceable range in both the vertical direction and the horizontal direction. If the correction member is displaced by an impact in this state, the amount of displacement of the member in the direction of the displacement is reduced, so that the camera shake cannot be sufficiently corrected.
[0008]
In order to avoid this inconvenience, in a camera that always performs camera shake correction when shooting an image, the camera shake correction member is placed at the above-described initial position immediately after switching from the mode for reproducing and displaying the image to the mode for shooting the image. To return to. Similarly, in a camera having a shooting mode in which camera shake correction is performed and a shooting mode in which camera shake correction is not performed, the camera shake correction member is returned to the initial position immediately after switching to the shooting mode in which camera shake correction is performed. . In addition, in a camera that performs camera shake correction only when a recording image is captured, the camera shake correction member is returned to the initial position immediately after an instruction to capture the recording image is given.
[0009]
[Problems to be solved by the invention]
However, if the camera shake correction member is returned to the initial position immediately after mode switching or immediately after an instruction to shoot a recording image, the start of the shooting operation may be delayed and a photo opportunity may be missed. In order to avoid this, if the photographing operation is performed in parallel with the returning operation of the correction member, the camera shake correction process is delayed, and it is difficult to appropriately perform the camera shake correction.
[0010]
Many digital cameras and video cameras have a function to provide live view by repeatedly capturing images and displaying the captured images, but when starting live view display immediately after mode switching. The camera shake correction member is returned to its initial position while the live view is displayed, and the live view changes even when the camera is stationary, giving an unnatural impression. End up.
[0011]
The present invention has been made in view of such problems, and an object of the present invention is to provide a camera that can immediately start shooting with camera shake correction and perform camera shake correction accurately.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention includes an imaging device that captures an image and a photographic optical system that guides light to the imaging device, and a part of the imaging device or the photographic optical system with respect to the optical axis of the photographic optical system. As a displacement member that can be displaced in a substantially vertical direction, a camera that corrects camera shake by displacing the displacement member is provided, and includes an actuator that displaces the displacement member by frictional frictional force. In which the driving force is transmitted to the displacement member via the friction coupling to displace the displacement member, and when the camera shake correction is not performed, the actuator is stopped and the position of the displacement member is maintained by the frictional force of the friction coupling. Mode setting means for setting the camera to either a shooting mode for shooting an image or a non-shooting mode for not shooting an image; and a shooting mode Correction determining means for determining whether or not to correct camera shake in the camera, and shooting instruction means for giving an image shooting instruction in accordance with an instruction from the user when the shooting mode is set by the mode setting means Whether or not switching to the correction mode in which the correction determination unit corrects camera shake is performed in a state where the photographing mode is set by the mode setting unit and it is determined that the camera shake is not corrected by the correction determination unit. The displacement member is returned to the initial position when the displacement member is deviated from the initial position during the period in which the displacement member is repeatedly determined and the period in which the mode setting unit sets the non-photographing mode.
[0013]
This camera uses an actuator that displaces a displacement member for correcting camera shake using a frictional force, and does not require a separate member for maintaining the position of the displacement member. When the shooting mode is set and camera shake is not corrected, it is determined whether or not the displacement member is deviated from the initial position before starting image shooting. Return to. Even when the non-photographing mode is set, it is determined whether or not the displacement member is displaced from the initial position. If the displacement member is displaced, the displacement member is returned to the initial position. Therefore, even when the camera shake correction displacement member is displaced due to an impact or the like while the camera shake correction is not performed , the camera shake correction member exists at the initial position when the camera mode is set to perform the camera shake correction. Become. For this reason, it is possible to start shooting with camera shake correction at the same time when the shooting mode for performing camera shake correction is set, and it is possible to accurately perform camera shake correction. When the live view display is started at the same time as the shooting mode for performing camera shake correction is set, it is possible to avoid unnatural live view. The non-shooting mode may be any mode as long as the camera performs some operation other than shooting.
[0014]
Here, the displacement member may be returned to the initial position only when the displacement of the displacement member from the initial position is a predetermined amount or more. By doing so, it is possible to avoid performing the operation of returning to the initial position until there is little deviation from the initial position of the displacement member for correcting camera shake and there is no problem with subsequent camera shake correction. it can.
[0015]
The non-shooting mode includes a playback mode for playing back an image or a standby mode for suspending some functions of the camera, and the displacement member is at an initial position during the period set by the mode setting means to the playback mode or the standby mode. It is preferable to return the displacement member to the initial position when it is deviated from. In playback mode and standby mode, there is a higher possibility of impact on the camera than in shooting mode, and the displacement member is likely to deviate from the initial position.However, by returning the displacement member to the initial position in playback mode or standby mode, Even when the displacement member is displaced from the initial position during this mode, the displacement member can be brought into a state without displacement before the photographing mode for performing camera shake correction.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of the optical configuration of the digital camera 1 according to the first embodiment. The digital camera 1 includes an imaging element 12 that performs photoelectric conversion to capture an image, a photographing lens 11 that forms an image of light from the photographing target on the imaging element 12, and a display unit 13 that displays the captured image. .
[0017]
The imaging element 12 is a CCD type area sensor, and is arranged and fixed perpendicular to the optical axis of the photographing lens 11. The photographing lens 11 is a zoom lens, and includes a plurality of lens groups for adjusting a focal length and a focal position, and a lens barrel 11b that holds these lens groups. The display unit 13 includes an LCD and is provided on the back surface of the digital camera 1. A live view is provided by repeatedly capturing an image with the image sensor 12 and displaying an image with the display unit 13, and the display unit 13 functions as a video finder.
[0018]
The photographic lens 11 includes a lens group 11a that is perpendicular to the optical axis and is held so as to be displaceable in two directions (vertical direction and horizontal direction). The digital camera 1 includes the lens group 11a. The camera shake is corrected by displacing it. For example, when a vertical camera shake occurs as indicated by an arrow V, the movement of the image on the image sensor 12 is suppressed by displacing the lens group 11a in the vertical direction as indicated by an arrow A.
[0019]
A schematic circuit configuration of the digital camera 1 is shown in FIG. The digital camera 1 includes an image sensor driving unit 14, an image processing unit 15, a recording unit 16, an image reproducing unit 17, an AF / AE calculation unit 18, a lens driving unit 19, a power supply unit 20, an operation unit 21, and a control unit 30. I have.
[0020]
The image sensor driving unit 14 controls photoelectric conversion of the image sensor 12 and performs predetermined analog processing such as amplification on the output signal of the image sensor 12. The image processing unit 15 digitizes the output signal of the image sensor 12 that has been subjected to analog processing, and performs processing such as pixel interpolation, white balance adjustment, and γ correction on the digital signal to generate image data representing the captured image. The recording unit 16 records the generated image data on a detachable recording medium M and reads out the image data recorded on the recording medium M. The image reproduction unit 17 processes the image data generated by the image processing unit 15 or the image data read from the recording medium M by the recording unit 16 to create image data suitable for display on the display unit 13.
[0021]
The AF / AE calculation unit 18 performs calculation for automatic focus adjustment (AF) and calculation for automatic exposure control (AE). The lens driving unit 19 drives the focal length adjustment lens group and the focal position adjustment lens group included in the photographing lens 11 in the optical axis direction. The lens driving unit 19 also drives the lens group 11a for camera shake correction in the optical axis direction, but does not displace the lens group 11a in a direction perpendicular to the optical axis. The power supply unit 20 includes a battery and supplies power to each unit.
[0022]
The operation unit 21 includes various operation members operated by a user. A switch is linked to each operation member, and the operation of the operation unit 21 is detected by opening and closing the switch. The switches include a main switch 22, an S1 switch 23, an S2 switch 24, a shooting / playback changeover switch 25, and a camera shake correction switch 26.
[0023]
The main switch 22 is used for instructing start and stop of power supply from the power supply unit 20. The S1 switch 23 and the S2 switch 24 are linked to the release button. When the release button is half-pressed, the S1 switch 23 is closed, and when the release button is fully pressed, the S2 switch 24 is closed. The S1 switch 23 is used for an instruction to start automatic focus adjustment and automatic exposure control, and the S2 switch 24 is used for an instruction to take a recording image and record the image. The shooting / playback switch 25 is used to instruct switching between a shooting mode for shooting an image and a playback mode for playing back and displaying an image recorded on the recording medium M. The camera shake correction switch 26 is used to instruct whether or not to perform camera shake correction in the shooting mode.
[0024]
The control unit 30 is composed of a microcomputer and controls the entire digital camera 1. The control unit 30 monitors the open / closed state of the switches 22 to 26 and reflects the operation of the operation unit 21 by the user in the control.
[0025]
When the shooting mode is specified by the shooting / playback switch 25, the control unit 30 causes the image sensor 12 to perform photoelectric conversion via the image sensor driving unit 14, and the image processing unit 15 processes the output signal. Image data is generated. Then, the image represented by the generated image data is displayed on the display unit 13 via the image reproduction unit 17 to provide a live view.
[0026]
In the meantime, when an instruction for focus adjustment and exposure control is given by the S1 switch 23, the output signal of the image sensor 12 is given to the AF / AE calculation unit 18, and the appropriate driving amount of the photographing lens 11 and the appropriate image sensor are selected. A simple photoelectric conversion time is calculated, and automatic focus adjustment is performed via the lens driving unit 19. Further, when a recording instruction is given by the S2 switch 24, automatic exposure control is performed through the image sensor driving unit 14, and image data representing an image photographed immediately thereafter is recorded through the recording unit 16 as a recording medium. Record in M.
[0027]
When the playback mode is designated by the shooting / playback switch 25, the control unit 30 reads out the image data from the recording medium M through the recording unit 16 and displays the image through the image playback unit 17. To display.
[0028]
In addition, the digital camera 1 includes a shake detection unit 31 and a shake correction unit 32. The shake detection unit 31 is composed of a vibration gyro using piezoelectric ceramics, and detects the angular velocity of rotation of the digital camera 1 caused by hand shake. Two vibration gyros are provided, and a vertical camera shake and a horizontal camera shake are detected.
[0029]
The shake correction unit 32 includes the above-described lens group 11a for correcting camera shake and a mechanism for holding and displacing the lens group 11a. The camera shake correction unit 32 will be described with reference to FIGS. 3 and 4. In these drawings, the Z axis is an axis parallel to the optical axis of the photographic lens 11, the X axis is an axis perpendicular to the optical axis of the photographic lens, and the Y axis is an axis perpendicular to both the Z axis and the X axis. The X-axis direction corresponds to the up-down direction, and the Y-axis direction corresponds to the left-right direction.
[0030]
The shake correction unit 32 includes a fixed frame 120, a moving frame 140 disposed to face the fixed frame 120, and a holding frame 160 that holds the lens group 11 a and is disposed between the fixed frame 120 and the moving frame 140. . The fixed frame 120 is supported by the lens barrel 11b so as to be movable in the Z-axis (optical axis) direction, and the movable frame 140 is attached to the fixed frame 120 so as to be movable in the X-axis direction (up and down). Yes. The holding frame 160 is attached to the moving frame 140 so as to be movable in the Y-axis direction (left and right).
[0031]
On the surface 120 a of the fixed frame 120 on the moving frame 140 side, an element fixing portion 122 to which one end face of the piezoelectric element 132 extending in the X-axis direction is fixed, and one end face to the other end face of the piezoelectric element 132 is fixed. A pair of rod support portions 124a and 124b for supporting the driven rod 134 movably in the X-axis direction are provided. On the opposite side of the optical axis, a pair of driven shaft support portions 126 a and 126 b that support both ends of the driven shaft 136 extending in the X-axis direction are provided in parallel with the drive rod 134. Further, a position detection element (PSD) 121x is provided between the driven shaft support portions 126a and 126b, and a PSD 121y is also provided between the rod support portion 124b and the driven shaft support portion 126b.
[0032]
On the surface 140b of the moving frame 140 on the fixed frame 120 side, a driven portion 148 that engages with the driving rod 134 of the fixed frame 120 by friction and receives a driving force from the driving rod 134, and a driven shaft 136 of the fixed frame 120 A sliding portion 149 that freely slides is provided. Furthermore, on the surface 140b, an element fixing portion 142 in which one end face of the piezoelectric element 152 extending in the Y-axis direction is fixed, and a drive rod 154 in which one end face is fixed to the other end face of the piezoelectric element 152 are provided in Y A pair of rod support portions 144a and 144b that are movably supported in the axial direction are provided. On the opposite side of the optical axis, a pair of driven shaft support portions 146a and 146b that support both ends of the driven shaft 156 extending in the Y-axis direction are provided in parallel with the drive rod 154.
[0033]
On the outer peripheral surface 160c of the holding frame 160, a driven portion 168 that engages with the driving rod 154 of the moving frame 140 by friction and receives a driving force from the driving rod 154, and a driven shaft 156 of the moving frame 140 slide freely. A moving sliding part 169 is provided. Further, the outer peripheral surface 160c is provided with a protrusion 166x protruding in the Y-axis direction and a protrusion 166y protruding in the X-axis direction. These protrusions 166x and 166y are directed toward the fixed frame 120 side. LEDs 161x and 161y that emit light are respectively provided. The LED 161x faces the PSD 121x of the fixed frame 120, and the LED 161y faces the PSD 121y of the fixed frame 120.
[0034]
The cross sections of the drive rods 134 and 154 and the driven parts 148 and 168 are shown in FIG. The driven parts 148 and 168 are each composed of two members 111 and 112 each having a V-shaped groove and coil springs 113a and 113b that connect them, and the driving rods 134 and 154 are grooves of the two members 111 and 112, respectively. Located between the parts. The coil springs 113a and 113b are slightly stretched, and the members 111 and 112 are pressed against the peripheral surfaces of the drive rods 134 and 154 by the contraction force. Thereby, when the drive rods 134 and 154 are displaced, a frictional force is generated between the drive rods 134 and 154 and the driven parts 148 and 168.
[0035]
The piezoelectric element 132 and the drive rod 134 of the fixed frame 120 form an actuator that displaces the lens group 11a in the X-axis direction together with the moving frame 140. The piezoelectric element 152 and the drive rod 154 of the moving frame 140 move the lens group 11a to the Y direction. It constitutes an actuator that is displaced in the axial direction. The piezoelectric elements 132 and 152 expand or contract according to the applied voltage, and the drive rods 134 and 154 fixed thereto are displaced according to the expansion and contraction of the piezoelectric elements 132 and 152.
[0036]
When the gradient of the voltage applied to the piezoelectric elements 132 and 152 is gentle, the piezoelectric elements 132 and 152 are gently expanded or contracted, and driven parts 148 and 168 engaged with the drive rods 134 and 154 by a frictional force. Follows the displacement of the drive rods 134,154. On the other hand, when the gradient of the applied voltage of the piezoelectric elements 132 and 152 is steep, the piezoelectric elements 132 and 152 rapidly expand or contract, and the driven parts 148 and 168 cannot follow the displacement of the drive rods 134 and 154. . Therefore, the lens group 11a can be displaced by alternately applying voltages having different polarities to the piezoelectric elements 132 and 152 with different gradients.
[0037]
When no voltage is applied to the piezoelectric elements 132 and 152, the drive rods 134 and 154 are not displaced, and the driven parts 148 and 168 engaged with the drive rods 134 and 154 are not displaced by the frictional force. 11a is kept in position.
[0038]
The position of the lens group 11a in the X-axis direction is detected by a PSD 121x that receives light from the LED 161x, and the position in the Y-axis direction is detected by a PSD 121y that receives light from the LED 161y. The control unit 30 controls the displacement of the lens group 11a by controlling the voltage application to the piezoelectric elements 132 and 152 while monitoring the outputs of the PSDs 121x and 121y.
[0039]
FIG. 6 shows an outline of a circuit configuration related to camera shake correction. In FIG. 6, a driving unit 170 is a circuit that applies a voltage to the piezoelectric elements 132 and 152, and is provided inside the lens barrel 11b.
[0040]
When the camera 30 is instructed to perform camera shake correction by the camera shake correction switch 26 in the photographing mode, the control unit 30 monitors the output of the camera shake detecting unit 31 and controls the piezoelectric element 132 or 152 according to the detected shake. Apply a voltage to correct camera shake. As a result, the shaking of the live view is suppressed, and the shaking of the recorded image hardly occurs.
[0041]
When the playback mode is designated by the shooting / playback switching switch 25, and when the switch 26 is instructed not to perform the camera shake correction even if the shooting mode is designated, the control unit 30 is for camera shake correction. The lens group 11a is maintained at the initial position. The initial position of the lens group 11a is a position where the optical axis of the lens group 11a itself coincides with the optical axes of other lens groups. The initial position is the center of the displaceable range of the lens group 11a in the X-axis (up and down) direction, and is also the center of the displaceable range of the lens group 11a in the Y-axis (left and right) direction. Therefore, when the lens group 11a is in the initial position, it is possible to correct the upward camera shake and the downward camera shake equally, and it is possible to correct the left camera shake and the right camera shake equally. is there. The control unit 30 stores the initial position of the lens group 11a.
[0042]
As described above, the control unit 30 keeps the lens group 11a at the initial position when the camera shake correction is not performed, but the impact exceeding the frictional force between the drive rods 134 and 154 and the driven units 148 and 168 is applied to the digital camera 1. Is added, the lens group 11a is displaced from the initial position. When camera shake correction is started while the lens group 11a is displaced from the initial position, the range in which the lens group 11a can be displaced becomes narrower in one of the vertical direction and the horizontal direction, and accurate correction cannot be performed.
[0043]
Therefore, the control unit 30 monitors the position of the lens group 11a with the PSDs 121x and 121y in the photographing mode in which no camera shake correction is performed, and returns the lens group 11a to the initial position if it is deviated from the initial position. Even in the reproduction mode, the position of the lens group is monitored, and if it deviates from the initial position, the lens group 11a is returned to the initial position. The digital camera 1 has a standby mode in which the photographing and display by the display unit 13 are stopped when the operation unit 21 is not operated for a predetermined time, and the power consumption of the power supply unit 20 is reduced. is there.
[0044]
FIG. 10 shows the flow of processing of the digital camera 1 in the shooting mode in which no camera shake correction is performed. First, the position of the lens group 11a for camera shake correction is detected (step # 105). Next, it is determined whether or not the deviation amount X from the initial position in the X-axis direction is equal to or greater than a predetermined value X0 (step # 110). If the deviation amount X is less than the predetermined value X0, the deviation in the Y-axis direction is determined. It is determined whether or not the deviation Y from the initial position is greater than or equal to a predetermined value Y0 (step # 115).
[0045]
If the displacement amount X in the X-axis direction is equal to or greater than the predetermined value X0 or the displacement amount Y in the Y-axis direction is greater than or equal to the predetermined value Y0, the lens group 11a is returned to the initial position (step # 120). When the deviation amount X in the X-axis direction is less than the predetermined value X0 and the deviation amount Y in the Y-axis direction is less than the predetermined value Y0, the lens group 11a is kept at the position at that time.
[0046]
Thereafter, it is determined whether or not a camera shake correction switch 26 is instructed to perform camera shake correction (step # 125). If the camera shake correction switch 26 is instructed, the camera mode is switched to a shooting mode in which camera shake correction is performed (step # 130). Further, it is determined whether or not the reproduction mode is designated by the photographing / reproduction switching switch 25 (step # 135), and if designated, the reproduction mode is switched (step # 140). Further, it is determined whether or not a stop of power supply is instructed by the main switch 22 (step # 145). If instructed, the power supply is stopped and the operation is ended (step # 150). When there is no instruction, the process returns to step # 105 and the above processing is repeated.
[0047]
It should be noted that the predetermined values X0 and Y0 used as a reference for determining whether or not to return the lens group 11a to the initial position may be arbitrarily determined or may be zero. However, if the shift amounts X and Y are so small that there is no problem with camera shake correction, there is no point in returning the lens group 11a to the initial position. Therefore, considering this, the predetermined values X0 and Y0 are set to appropriate positive values. The value is preferably determined.
[0048]
FIG. 11 shows a processing flow of the digital camera 1 in the reproduction mode. First, the position of the lens group 11a for camera shake correction is detected (step # 205). Next, it is determined whether or not the deviation amount X from the initial position in the X-axis direction is equal to or greater than a predetermined value X0 (step # 210). If the deviation amount X is less than the predetermined value X0, the deviation in the Y-axis direction is determined. It is determined whether or not the deviation Y from the initial position is greater than or equal to a predetermined value Y0 (step # 215).
[0049]
If the displacement amount X in the X-axis direction is equal to or greater than the predetermined value X0 or the displacement amount Y in the Y-axis direction is equal to or greater than the predetermined value Y0, the lens group 11a is returned to the initial position (step # 220). When the deviation amount X in the X-axis direction is less than the predetermined value X0 and the deviation amount Y in the Y-axis direction is less than the predetermined value Y0, the lens group 11a is kept at the position at that time.
[0050]
Thereafter, it is determined whether or not a shooting mode has been designated by the shooting / playback switch 25 (step # 225). If designated, the mode is switched to the shooting mode (step # 230). Further, it is determined whether or not the main switch 22 has instructed to stop power supply (step # 235). If instructed, the power supply is stopped and the operation is ended (step # 240). If there is no instruction, the process returns to step # 205 and the above processing is repeated.
[0051]
FIG. 7 shows an outline of the optical configuration of the digital camera 2 according to the second embodiment. In the digital camera 2 of the present embodiment, the image sensor 12 is held so as to be displaceable in two directions (vertical direction and left-right direction) perpendicular to the optical axis of the photographing lens 11, and the image sensor 12 is displaced. Correct camera shake. For example, when vertical camera shake occurs as indicated by the arrow V, the image sensor 12 is displaced in the vertical direction as indicated by the arrow B, thereby suppressing the movement of the image on the image sensor 12.
[0052]
Except for this point, the digital camera 2 has the same configuration as that of the digital camera 1, and the circuit configuration is as shown in FIG. In the digital camera 2, the shake correction unit 32 includes the image sensor 12 and a mechanism that holds and displaces the image sensor 12. The mechanism for holding and displacing the image sensor 32 is configured in the same manner as the mechanism shown in FIGS. 3 to 5 for holding and displacing the lens group, and redundant description is omitted. The circuit configuration relating to camera shake correction is also as shown in FIG.
[0053]
Also in the digital camera 2, the position of the image sensor 12 is monitored by the PSDs 121x and 121y in modes other than the shooting mode in which camera shake correction is performed, and the image sensor 12 is returned to the initial position if the position deviates from the initial position. The processing flow in the shooting mode in which no camera shake correction is performed and in the playback mode is as shown in FIGS. 10 and 11. In steps # 105 and # 205, the position of the image sensor 12 is detected, and steps # 120 and # 220. Then, the image sensor 12 is returned to the initial position.
[0054]
In the digital camera 2 that performs camera shake correction by displacing the image sensor 12, the photographic lens 11 can be easily replaced. Since it is not necessary to provide a lens group for camera shake correction in each photographing lens 11, it is possible to reduce the cost of the entire lens exchangeable camera system.
[0055]
FIG. 8 shows an outline of the optical configuration of the digital camera 3 according to the third embodiment. The digital camera 3 of the present embodiment is obtained by adding an optical viewfinder 41 to the digital camera 2 of the second embodiment. The optical viewfinder 41 includes a mirror 42 and an eyepiece lens 43. The digital camera 3 is a single-lens reflex camera, and the light transmitted through the photographing lens 11 is branched and guided to both the image sensor 12 and the optical viewfinder 41. For this purpose, a mirror 44 is disposed on the optical path from the photographing lens 11 to the image sensor 12.
[0056]
The mirror 44 rotates about an axis perpendicular to the optical axis of the photographing lens 11, and an advancing position that obliquely intersects the optical path from the photographing lens 11 to the image sensor 12 and a retracted position that does not intersect the optical path. And take. 8A shows a state where the mirror 44 is in the advanced position, and FIG. 8B shows a state where the mirror 44 is in the retracted position. When the mirror 44 is in the advanced position, all of the light is guided to the optical finder 41, and photographing cannot be performed, and the optical finder 41 can be used. On the other hand, when the mirror 44 is in the retracted position, all of the light is guided to the image sensor, so that an image can be taken, and it can also be used as a live view video finder displayed on the display unit 13.
[0057]
The digital camera 3 includes an eyepiece detection unit 45 for detecting that the user is observing the image of the optical finder 41, and the mirror 44 is used when the user is observing the image of the optical finder 41. Is set to the advanced position, otherwise the mirror 44 is set to the retracted position. The eyepiece detection unit 45 includes a light-emitting element that emits infrared light and a light-receiving element that detects infrared light reflected by the user's face. It is possible to switch between using the optical finder 41 and the video finder.
[0058]
An outline of the circuit configuration of the digital camera 3 is shown in FIG. This is obtained by adding an eyepiece detecting unit 45 and a mirror driving unit 46 for rotating the mirror 44 to the circuit configuration of the digital cameras 1 and 2 shown in FIG.
[0059]
In the digital camera 3, an image cannot be taken when the mirror 44 is in the advanced position. Therefore, while the eyepiece detection unit 45 detects that the user is observing the image of the optical finder 41, In order to avoid wasteful consumption, the image pickup by the image sensor 12 and the image display by the display unit 13 are not performed. A mode that provides an image of the optical finder 41 without performing shooting and live view display is referred to as an observation mode.
[0060]
Also in the digital camera 3, the position of the image sensor 12 is monitored by the PSDs 121 x and 121 y in the shooting mode and the playback mode in which no camera shake correction is performed, and the image sensor 12 is returned to the initial position if it is deviated from the initial position. Further, even in the observation mode, the position of the image sensor 12 is monitored, and if it deviates from the initial position, the image sensor 12 is returned to the initial position. This is performed regardless of whether or not the camera shake correction switch 26 is instructed to perform camera shake correction in the shooting mode.
[0061]
The flow of processing in the observation mode when not instructed to perform camera shake correction and when instructed is shown in FIGS. 12 and 13, respectively. First, the position of the image sensor 12 for camera shake correction is detected (steps # 305 and # 405). Next, it is determined whether or not the deviation amount X from the initial position in the X-axis direction is equal to or greater than a predetermined value X0 (steps # 310 and # 410). If the deviation amount X is less than the predetermined value X0, the Y-axis It is determined whether or not the deviation amount Y from the initial position in the direction is greater than or equal to a predetermined value Y0 (steps # 315 and # 415).
[0062]
If the displacement amount X in the X-axis direction is equal to or larger than the predetermined value X0 or the displacement amount Y in the Y-axis direction is equal to or larger than the predetermined value Y0, the image sensor 12 is returned to the initial position (Steps # 320 and # 420). ). When the deviation amount X in the X-axis direction is less than the predetermined value X0 and the deviation amount Y in the Y-axis direction is less than the predetermined value Y0, the image sensor 12 is kept at the position at that time.
[0063]
Thereafter, the eyepiece detection unit 45 determines whether or not the user has finished observing the image of the optical viewfinder 41 (steps # 325 and # 425). View display is started (steps # 330 and # 430). Further, it is determined whether or not the reproduction mode is designated by the photographing / reproduction switching switch 25 (steps # 335 and # 435), and if designated, the reproduction mode is switched (steps # 340 and # 440). Further, it is determined whether or not the main switch 22 has instructed to stop the power supply (steps # 345 and # 445). If instructed, the power supply is stopped and the operation is terminated (steps # 350 and # 445). 450). If there is no instruction, the process returns to step # 305 or # 405 and the above processing is repeated.
[0064]
The image of the optical viewfinder 41 is affected by camera shake as in the live view. Instead of performing camera shake correction by displacing the image sensor 12, if the camera shake correction is performed by displacing some lens groups 11a as in the first embodiment, the image of the optical viewfinder 41 is displayed. It is possible to correct camera shake. Thus, when it is possible to perform camera shake correction even in the observation mode, it is preferable that the user can select whether or not to perform camera shake correction. This designation may be performed by 26 on the camera shake correction switch, as in the case of the photographing mode.
[0065]
In each of the above embodiments, a digital camera has been described as an example, but the present invention can also be applied to a video camera. Also, here, the configuration for holding and displacing the camera shake correction member by the frictional force is shown, but the present invention is a correction member for a period in which no image is taken regardless of the configuration for holding and displacing the correction member. It can be applied to any camera that does not have a mechanism for securely fixing the camera.
[0066]
【The invention's effect】
In the camera of the present invention, before the start of image capturing in a shooting mode in which no camera shake correction is performed and in the non-shooting mode, the displacement member is returned to the initial position if the camera shake correcting displacement member is displaced from the initial position. Therefore, it is possible to start shooting with camera shake correction at the same time as setting the shooting mode for performing camera shake correction, and the possibility of missing a photo opportunity is greatly reduced. In addition, camera shake correction is also performed accurately. Furthermore, when the live view display is started at the same time as the shooting mode for performing the camera shake correction, the unnaturalness of the live view can be avoided.
[0067]
When deviations from the initial position of the displacement member for camera-shake correction is not less than the predetermined amount only when the displacement member so as to return to the initial position, deviation from the initial position of the displacement member is any trouble in image stabilization after It is possible to avoid the waste of returning the displacement member to the initial position until there is no such a problem.
[0068]
In particular, if the displacement member is returned to the initial position in the playback mode or standby mode in which the camera is likely to be shocked, there is a high possibility that the displacement member can be in a state of no deviation before the shooting mode in which camera shake correction is performed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing an optical configuration of a digital camera according to a first embodiment.
FIG. 2 is a block diagram schematically showing a circuit configuration of the digital camera according to the first and second embodiments.
FIG. 3 is an exploded perspective view schematically showing a mechanism for camera shake correction.
FIG. 4 is a perspective plan view schematically showing a main part of a mechanism for camera shake correction.
FIG. 5 is a cross-sectional view schematically showing a main part of a mechanism for camera shake correction.
FIG. 6 is a block diagram schematically showing a circuit configuration relating to camera shake correction of the digital camera of the first, second, and third embodiments.
FIG. 7 is a cross-sectional view schematically showing an optical configuration of a digital camera according to a second embodiment.
FIG. 8 is a cross-sectional view schematically showing an optical configuration of a digital camera according to a third embodiment.
FIG. 9 is a block diagram schematically illustrating a circuit configuration of a digital camera according to a third embodiment.
FIG. 10 is a flowchart showing a flow of processing in a shooting mode in which no camera shake correction is performed in the digital camera according to the first, second, and third embodiments.
FIG. 11 is a flowchart showing the flow of processing in the playback mode of the digital camera of the first, second, and third embodiments.
FIG. 12 is a flowchart showing a flow of processing in an observation mode in which no camera shake correction is performed in the digital camera according to the third embodiment.
FIG. 13 is a flowchart showing a flow of processing in an observation mode for performing camera shake correction of the digital camera of the third embodiment.
[Explanation of symbols]
1, 2, 3 Digital camera 11 Shooting lens 11a Camera shake correction lens group 11b Lens barrel 12 Image sensor 13 Display unit 14 Image sensor drive unit 15 Image processing unit 16 Recording unit 17 Image playback unit 18 AF / AE calculation unit 19 Lens Drive unit 20 Power supply unit 21 Operation unit 22 Main switch 23 S1 switch 24 S2 switch 25 Shooting / playback switch 26 Camera shake correction switch 30 Control unit 31 Camera shake detection unit 32 Camera shake correction unit 41 Optical viewfinder 42 Mirror 43 Eyepiece 44 Mirror 45 Eyepiece Detection unit 46 Mirror drive unit 111, 112 Driven member 113a, 113b Coil spring 120 Fixed frame 140 Moving frame 160 Holding frame 132, 152 Piezoelectric element 122, 142 Element fixing unit 134, 154 Drive rod 124a, 124b, 144a, 144b Rod Branch Holding portion 126a, 126b, 146a, 146b driven shaft support portion 136, 156 driven shaft 121x, 121y PSD
148, 168 Driven part 149, 169 Sliding part 161x, 161y LED
166x, 166y protrusion

Claims (3)

As a displacement member that includes an image sensor that captures an image and a photographing optical system that guides light to the image sensor, and that can displace a part of the image sensor or the photographing optical system in a direction substantially perpendicular to the optical axis of the photographing optical system A camera that corrects camera shake by displacing the displacement member, and includes an actuator that displaces the displacement member by the frictional force of the frictional coupling, and when correcting the camera shake, the actuator is operated to drive the driving force via the frictional coupling. When the displacement member is displaced by transmitting to the displacement member and the camera shake correction is not performed, the actuator is stopped and the position of the displacement member is maintained by the frictional force of the friction coupling.
Mode setting means for setting the camera to one of a shooting mode for shooting an image and a non-shooting mode for not shooting an image;
Correction determination means for determining whether or not to correct camera shake in the shooting mode;
A shooting instruction unit that gives an instruction to shoot an image in response to an instruction from the user when the shooting mode is set by the mode setting unit;
It is repeatedly determined whether or not switching to the correction mode in which the camera shake correction is performed by the correction determination unit is set in the shooting mode by the mode setting unit and it is determined that the camera shake is not corrected by the correction determination unit. A camera that returns the displacement member to the initial position when the displacement member is deviated from the initial position during the period during which the displacement setting member is set to the non-photographing mode by the mode setting means.   2. The camera according to claim 1, wherein the displacement member is returned to the initial position only when the displacement of the displacement member from the initial position is a predetermined amount or more.   The non-shooting mode includes a playback mode for playing back an image or a standby mode for suspending some functions of the camera. The camera according to claim 1 or 2, wherein the displacement member is returned to the initial position when the position is deviated from the position.

Images