JP2007093953A - Shake correcting apparatus for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shake correcting apparatus for camera which is compact by simplifying its structure, has wide correction range and is excellent in followability. <P>SOLUTION: Sensor modules 60P and 60Y for detecting the camera shake in pitch and yaw directions are fixed on the outer frame 16 fixed to a housing. An intermediate frame 20 is supported related to the outer frame 18 so that it may freely oscillate around a second axis Y vertical to the outer frame 18. An inner frame 22 is supported related to the intermediate frame 20 so that it may freely oscillate around a first axis P horizontal to the intermediate frame 20. A camera module 24 incorporating a photographic lens and an image sensor is fixed in the inner frame 22. The camera shake is corrected in the whole camera module 24 by oscillating the inner frame 22 in the pitch direction in accordance with a camera shake signal from the sensor module 60P and also oscillating the intermediate frame 20 in the yaw direction in accordance with a camera shake signal from the sensor module 60Y. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a camera shake correction apparatus, and more particularly, to a camera shake correction apparatus that corrects camera shake that occurs during shooting of a still image and that can capture a blur-free image.

Even if there is a camera shake during the shooting of a still image, a camera shake correction apparatus has been put into practical use in which a clear shooting can be performed by preventing an image blur on the imaging plane. As known from Patent Documents 1 and 2 and the like, a camera shake correction device for a digital camera mainly includes a method of moving a part of lenses in a photographing optical system and a CMOS disposed on an imaging surface of the photographing optical system. There is a method of moving an image sensor such as a sensor or a CCD sensor.
JP 2004-348147 A JP 2004-274242 A

  These camera shake correction apparatuses include a vibration sensor such as an angular velocity sensor that detects camera shake, a calculation unit that calculates a correction movement amount of a lens or an image sensor based on a camera shake signal from the vibration sensor, and a calculation unit. And an actuator that moves the lens and the image sensor in response to the correction signal. In either method, the vibration sensor detects the shake angle of the photographic optical axis associated with camera shake as a camera shake signal, and moves and adjusts the lens and image sensor in a plane perpendicular to the photographic optical axis based on the camera shake signal. It has become.

  However, in these image stabilization devices, it is necessary to adjust the movement of the lens and image sensor in a plane perpendicular to the photographing optical axis, and not only the structure after the actuator becomes complicated and large, but also in terms of cost. The burden is also great. In addition, since the angular displacement of the photographic optical axis detected by the vibration sensor has to be corrected by converting it to linear movement on xy orthogonal coordinates, there is also a drawback that it takes a long time for the arithmetic processing. Due to such structural limitations, effective correction becomes difficult when the angle of deflection of the photographic optical axis exceeds about 30 minutes, and the shutter speed corresponding to the signal charge accumulation time of the image sensor is 1/15. If it is later than 1 second to 1/8 second, it is impossible to follow the whole period, and effective camera shake correction cannot be performed when shooting a night scene or the like.

  The present invention has been made in consideration of the above-described conventional technology. For example, the present invention can be miniaturized to a degree that can be applied to a digital camera built in a mobile phone, has a low cost burden, and further has a housing swing angle. It is an object of the present invention to provide a camera shake correction device that can perform effective camera shake correction even when the angle is about 1 ° to 2 ° and that can sufficiently follow even when the shutter speed exceeds 1 second.

  In achieving the above object, the camera shake correction apparatus of the present invention accommodates a camera module in which a photographing lens and an image sensor are integrated in a housing, and the camera module is orthogonal to the photographing optical axis inside the housing. In addition, it has a configuration that swingably supports the first axis and the second axis that intersect at right angles to each other, and controls the posture of the camera module inside the case according to the shake of the case detected by the camera shake sensor. Therefore, camera shake correction during still image shooting is performed.

  As a structure for supporting the camera module so as to be swingable around the first axis and the second axis in the housing and for adjusting and controlling the posture of the camera module, an inner frame on which the camera module is fixed is viewed from the outside. An inner frame that is swingably supported about the first axis; an outer frame that is fixed to the housing and supports the middle frame from the outside so as to be swingable about the second axis; Built in either the frame or the middle frame, the first drive means for swinging the inner frame around the first axis in response to a camera shake signal from the camera shake sensor, and incorporated in either the middle frame or the outer frame And a second driving means for swinging the middle frame around the second axis in accordance with a camera shake signal from the camera shake sensor, and the first axis and the second axis on the photographing optical axis. Combining the inner and outer frames so that they intersect at a single point Is an interest.

  As the first and second drive means, a stepping motor, a reduction gear train that reduces the rotation of the stepping motor, and a cam that rotates integrally with the final stage gear and swings the inner frame and the inner frame, respectively, are effective. In order to simplify the structure, it is advantageous to assemble the first driving means to the inner frame and the second driving means to the outer frame. Further, the middle frame and the outer frame are configured by rectangular cylinders surrounding the imaging optical axis, and a plurality of gears constituting the reduction gear train are arranged on one side of each rectangular cylinder in a direction substantially perpendicular to the imaging optical axis. In addition, the camera shake correction device can be made compact particularly in the direction of the photographing optical axis, and can be easily incorporated into, for example, a mobile phone having a casing thickness of about several tens of millimeters.

  It is also possible to adopt a structure in which each stepping motor, gear train, and cam constituting the first and second drive means are composed of common parts and assembled to the inner frame and the outer frame by holding plates having the same shape, respectively. Thus, the manufacturing cost and the number of assembly steps can be further reduced and misassembly can be prevented. Further, by suppressing the maximum diameter of the cam to be equal to or less than the outer diameter of the gear in the final stage, it is possible to configure them with a low-cost integrally molded product. By making the cam a constant velocity cam, it is possible to simplify the control of the first and second driving means based on the camera shake signal.

  Furthermore, a pair of circuit components for controlling the amount of rotation of the stepping motor in accordance with a camera shake signal is attached to each holding plate, and a vertical direction (pitch direction) shake and a horizontal direction (yaw direction) shake of the housing are detected. By attaching the camera shake sensor to the outer frame, the camera module and the camera shake correction device can be unitized, and the assembling work into the housing can be greatly simplified as compared with the conventional device.

  According to the camera shake correction apparatus of the present invention, in accordance with the camera shake signal from the camera shake sensor, camera shake correction can be performed by swinging the camera module in which the photographing optical system and the image sensor are integrated inside the housing, and the correction range. As a result, it is possible to improve the followability while expanding the image quality and to obtain a camera shake correction effect with high accuracy and excellent responsiveness. The camera module can be freely swung in the pitch direction and the yaw direction by a gimbal mechanism comprising an inner frame, an inner frame that supports the inner frame in a swingable manner, and an outer frame that supports the inner frame in a swingable manner. Since the first and second driving means can be efficiently incorporated between the inner frame and the outer frame, the above effect can be ensured while simplifying the structure.

  In addition, if the middle frame and the outer frame are formed of rectangular cylinders, the reduction gear train used in the first and second driving means is disposed on one surface of each rectangular cylinder and is substantially orthogonal to the photographing optical axis. Since the individual gears can be arranged in the orientation, it is possible to greatly reduce the thickness of the entire image stabilizer in the optical axis direction, and it can be easily incorporated into devices with thin casings such as mobile phones. be able to. In carrying out the present invention, various ideas for reducing the manufacturing cost can be applied, and these will be described in the following embodiments.

  Hereinafter, an embodiment in which the device of the present invention is used in a foldable mobile phone will be described with reference to the drawings. As shown in FIG. 1, in the mobile phone 2, a transmission unit 3 and a reception unit 4 are connected by a hinge 5. Known operation buttons such as dial buttons and function buttons are arranged on the inner surface side of the transmission unit 3, and a memory card 6 can be inserted into a slot formed on the side surface as shown in the figure. A well-known display panel is incorporated on the inner surface side of the receiver unit 4 and can be used as a standby screen display, a dial display during a call, or a monitor screen during mail transmission.

  On the outer surface of the reception unit 4, a display panel 8 for notification of incoming calls, an illumination window 9, and a photographing window 10 are provided. An LED that emits white light is incorporated in the back of the illumination window 9, and the subject can be illuminated if the brightness is insufficient when a still image is captured through the imaging window 10. A camera unit 12 is incorporated in the back of the photographing window 10. As will be described in detail later, the camera unit 12 includes a photographing lens, an image sensor, and a camera shake correction device, and photographs a subject image obtained through the photographing window 10.

  When the transmission unit 3 and the reception unit 4 are opened by a certain angle or more to expose the operation buttons, and the mode is switched to the camera mode by an appropriate button operation, the display panel provided on the inner surface of the reception unit 4 functions as a finder. A through image captured by the unit 12 is displayed. When framing is performed while observing a through image and the function button assigned to the release button is pressed, the still image at that moment can be taken, and the image data is recorded and stored in the internal memory or the memory card 6. can do.

  In FIG. 2 showing a cross section of the main part of the receiver unit 4, a transparent cover plate 15 is fitted in the photographing window 10, and a camera unit 12 is provided in the back thereof. The camera unit 12 is positioned and fixed to a rigid printed circuit board 19 by pins 18a projecting at four positions on the rear end side of the outer frame 18, and the printed circuit board 19 is secured to the casing 7 of the receiver unit 4 with screws. It is fixed.

  As described above, the camera unit 12 includes an outer frame 18 fixed to the printed circuit board 19, an inner frame 20 disposed inside the outer frame 18, an inner frame 22 disposed further inside, and an inner frame 22. And a camera module 24 fixed to the camera. The middle frame 20 is swingably supported by support shafts 18 b and 18 b that project from the inner side of the outer frame 18. The swing axis of the middle frame 20 defined by the pair of support shafts 18b, 18b coincides with a vertical line orthogonal to the photographing optical axis S, and thereby the middle frame 20 can swing in the yaw direction. A pair of support shafts projecting in a direction perpendicular to the paper surface are integrally formed on the inner side of the middle frame 22, and thereby the inner frame 24 is supported so as to be swingable. The swing axis of the inner frame 24 defined by the pair of support shafts that support the inner frame 24 coincides with a horizontal line orthogonal to the photographing optical axis S, and thereby the inner frame 24 can swing in the pitch direction. The pitch-direction oscillating axis and the yaw-direction oscillating axis intersect the photographing optical axis S at one point.

  The camera module 24 includes a plurality of photographic lenses 26 incorporated in a lens barrel 25 and a circuit board 28 on which an image sensor 27 is mounted at the rear end of the lens barrel 25. The camera module 24 is incorporated in the inner frame 22. ing. The photographing lens 26 includes a focusing lens 26a, and is held by a movable cylinder 29 that is movable in the optical axis direction. The movable cylinder 29 is moved by a stepping motor (not shown) incorporated in the inner frame 22 and driven during focusing, and moves the lens 26a to the in-focus position. Of course, a pan focus type lens can be used as the photographing lens 26. In addition, it is possible to provide the photographic lens 26 with a zooming function such as a zoom lens. In this case, it is necessary to attach a zooming actuator to the inner frame 22 or the lens barrel 25 as well. Further, it is desirable that the photographing lens 26 is incorporated in the lens barrel 25 as a whole. However, as long as it does not affect the camera shake correction, the cover plate 15 may be given power and used as a part of the photographing lens. A gear housing portion 18c is formed integrally with the lower portion of the outer frame 18, and a holding plate 30 holding a plurality of gears constituting the reduction gear train is assembled.

  As shown in FIG. 3, the camera unit 12 is combined so that a rectangular cylindrical outer frame 18, a rectangular cylindrical inner frame 20, and a rectangular cylindrical inner frame 22 are sequentially connected to the inside. The camera module 24 is housed in a rectangular parallelepiped shape as a whole. As described above, the inner frame 22 to which the camera module 24 is fixed is swingable with respect to the middle frame 20 about the first axis P that intersects the photographing optical axis S horizontally, and the middle frame 20 is the photographing light. It is swingable with respect to the outer frame 18 around a second axis Y perpendicular to the axis S. As a result, the camera module 24 is supported by a gimbal mechanism extending from the inner frame 22 to the outer frame 18, and the photographing optical axis S can be directed in an arbitrary direction.

  The outer frame 18, the inner frame 20, and the inner frame 22 are each formed of a plastic molded product. Depending on the plastic material or molding method, the outer frame 18 having a particularly large size may be a pincushion mold when taken out from the molding die. May be deformed. If the outer frame 18 is deformed into a pincushion type, the inner wall of the outer frame 18 and the outer wall of the middle frame 20 may come into contact with each other, which may hinder the swinging of the middle frame 20, but as shown in FIG. By projecting a pin 18a extending in the optical axis direction at the rear end of 18 and fitting it into a rigid printed circuit board 19, the outer frame 18 is fixed with its deformation corrected. Become.

  Stepping motors 35 and 36 are used to swing each of the inner frame 22 and the middle frame 20 around the first axis P and the second axis Y. An example of the camera shake correction control circuit for driving these motors is shown in FIG. Shown in The P camera shake correction control circuit 38 includes a P correction amount calculation circuit 38a and a driver 38b. A P camera shake signal corresponding to the shake amount in the pitch direction of the housing 7 is input to the P correction amount calculation circuit 38a. Similarly, the Y camera shake correction control circuit 39 includes a Y correction amount calculation circuit 39a and a driver 39b, and a Y camera shake signal corresponding to the shake amount of the housing 7 in the yaw direction is input to the Y correction amount calculation circuit 39a. . The shake direction of the casing 7 due to camera shake varies, but if a pair of angular velocity sensors having sensitivity only in the pitch direction and the yaw direction are used as the vibration sensor, the P camera shake signal and the Y It can be detected by being decomposed into two types of camera shake signals.

  Each of the correction amount calculation circuits 38a and 39a calculates a signal for swinging the inner frame 22 and the inner frame 20 so as to cancel the shake of the casing 7 represented by the P camera shake signal and the Y camera shake signal. Accordingly, the stepping motors 35 and 36 are driven via the drivers 38b and 39b. In this embodiment, for example, if the casing 7 is swung by 1 ° in the pitch direction, the inner frame 22 may be swung by 1 ° in the reverse pitch direction. In addition, since the first axis P and the second axis Y intersect at one point of the photographing optical axis S, the middle frame 20 is shaken in the opposite direction to the shaking direction of the housing 7 in the same manner with respect to camera shake in the yaw direction. Move it. Accordingly, each of the correction amount calculation circuits 38a and 39a only needs to perform calculation considering the correction for the mechanical interlocking system after the stepping motors 35 and 36, and the calculation processing time can be almost ignored.

  The camera shake correction at the time of still image shooting only needs to drive the stepping motors 35 and 36 only during the period in which the image sensor 27 is accumulating signal charges, so that the shutter signal corresponding to the timing of the accumulation start and accumulation end is corrected. The stepping motors 35 and 36 are preferably turned off during an unnecessary period when they are input to the quantity calculation circuits 38a and 39a. Further, a control signal is also input to the correction amount calculation circuits 38a and 39a. This control signal is a signal that returns the stepping motors 35 and 36 to the initial position after the photographing is completed, or due to other factors. This is used as a delay signal when the correction needs to be delayed, for example, when a focusing process by the autofocus device is required before starting the camera shake correction.

  As shown in FIG. 5, support shafts 18 b and 18 b project from the upper and lower inner wall surfaces of the outer frame 18, and are inserted into bearing holes 20 a and 20 a formed on the upper and lower surfaces of the middle frame 20, thereby The second shaft Y is assembled so as to be swingable with respect to the outer frame 18. A torsion spring 45 is applied to one of the support shafts 18b, one end of which presses a pin 20b projecting from the middle frame 20, and the middle frame 20 is urged counterclockwise with respect to the second axis Y. Similarly, support shafts 20c and 20c are projected on the inner surfaces of both side walls of the inner frame 20, and are inserted into bearing holes 22a and 22a formed on both side walls of the inner frame 22, so that the inner frame 22 is first. The shaft P is assembled so as to be swingable with respect to the middle frame 20. A torsion spring 46 is applied to one support shaft 20c, one end of which presses a pin projecting from the left side wall outer surface of the inner frame 22, and the inner frame 22 is urged counterclockwise with respect to the first shaft P. The

  The holding plate 30 is attached to the outer frame 18 by hook claws 30a so as to cover the gear housing portion 18c integrally formed on the bottom surface of the outer frame 18. On the upper surface side of the holding plate 30, a stepping motor 36 that is driven at the time of correcting shake in the yaw direction and a gear train 51 for reduction are assembled, and a cam 52 is provided integrally with the final stage gear. The cam 52 protrudes upward from an opening 54 formed in the lower wall of the outer frame 18, passes through an opening edge formed in the lower wall of the middle frame 20, and a cam follower 55 protruding from the opening edge is provided with a torsion spring 45. It abuts on the cam surface by the force. The components from the stepping motor 36 to the cam 52 constitute second drive means for swinging the middle frame 20 around the second axis Y. The side surface of the cam 52 is used as a cam surface, but the maximum diameter of the cam surface is smaller than the outer diameter of the gear in the final stage and smaller than the outer diameter of the shaft portion inserted through the opening 54. Therefore, the mold for integrally molding the cam 52 with the gear in the final stage can have a simple structure in which the molded product can be removed from the axial direction, which is advantageous in reducing the manufacturing cost. Become.

  A flexible printed wiring board (FPC) 58 is fixed to the bottom surface side of the holding plate 30 by adhesion or the like. The FPC 58 includes an HP sensor 59 with a built-in reflective photosensor, a Y-shake correction control circuit 39 that is integrated into one chip, an angular velocity sensor that detects shake in the yaw direction of the housing 7, and a shake amount detection circuit. The unitized sensor module 60Y is mounted, and after these mounted components are positioned by the recess formed on the bottom surface of the holding plate 30, the FPC 58 is fixed. The HP sensor 59 is used to photoelectrically detect a signal portion provided on the bottom surface of the last gear through an opening formed in the holding plate 30 and detect whether or not the last gear is in the initial position. The FPC 58 is also mounted with a sensor module 60P in which an angular velocity sensor for detecting a shake in the pitch direction and a shake amount detection circuit are unitized, and the sensor module 60P is positioned by a recess formed in the outer frame 18. The FPC 58 is fixed so as to cover the side surface of the outer frame 18.

  In exactly the same manner, a gear housing portion 20d is formed on one side wall of the middle frame 20, and a holding plate 62 is attached to the middle frame 20 by hook claws 62a so as to cover the gear housing portion 20d. The holding plate 62 has the same shape as the holding plate 30, and the first driving means comprising the same components as the stepping motor 36, the gear train 51, and the cam 52 assembled to the holding plate 30 is assembled to the side wall of the middle frame 20. It is done. The cam 63 integrally formed with the gear in the final stage protrudes into the inner frame 20 through the opening 64 and enters the recess formed in the side wall of the inner frame 22, and is a cam follower 65 protruding from the inner peripheral wall of the recess. Comes into contact with the cam surface by the urging of the torsion spring 46. The first drive means has an action of swinging the inner frame 22 around the first axis P.

  If the outer frame 18 has a rectangular cylindrical shape as described above, the gear train 51 extending from the spindle gear of the stepping motor 36 to the final gear along the flat surface of the outer frame 18 is configured by a simple spur gear combination. In addition, since these gears can be arranged in a direction substantially orthogonal to the photographing optical axis S, the length of the outer frame 18 in the optical axis direction can be shortened to about 10 mm, and a camera shake correction function is provided. The provided camera unit 12 can be sufficiently incorporated into a mobile phone. Of course, the same applies to the middle frame 20, and all the components can be accommodated in the outer frame 18 by accommodating the inner frame 22 and the camera module 24 so as not to protrude from the front and rear of the middle frame 20. Further, if the holding plates 30 and 62 and the first and second driving means assembled therewith are made to have the same configuration, any of them may be assembled to the outer frame 18 or the inner frame 20, and only the parts are shared. In addition, misassembly can be prevented and manufacturing costs can be reduced.

  An FPC 66 is fixed to the holding plate 62 by adhesion or the like. Similar to the HP sensor 59, the FPC 66 is equipped with an HP sensor 68 that detects whether or not the final stage gear supported by the holding plate 62 is in the initial position, and is held by fixing the FPC 66 to the holding plate 62. It is stably positioned and fixed in the concave portion of the plate 62. As is clear from FIG. 3, the holding plate 62 is assembled to the side wall of the middle frame 22, and the FPC 66 is fixed to the holding plate 62, all of which are designed to fit within the outer frame 18 with a margin. When the middle frame 20 swings around the second axis Y, a part thereof does not contact the outer frame 18. Although not shown, a P camera shake correction control circuit 38 that controls the stepping motor 35 that is driven during camera shake correction in the pitch direction is also mounted on the FPC 66. The inner cylinder 22 is connected to an FPC 67 for driving the image sensor 27 and taking out an image signal. The swing angle of the inner cylinder 22 for correcting camera shake is about 1 ° to 2 ° at most. Therefore, the flexibility of the FPC 67 does not hinder the swinging of the inner cylinder 22.

  Since the cam follower 55 abuts against the cam surface of the cam 52 by the urging force of the torsion spring 45, the inner frame 20 swings around the second axis Y according to the cam surface shape when the cam 52 rotates. Similarly, when the cam 63 rotates, the inner frame 22 swings around the first axis P. In order to easily control the amount of rotation of the cams 52 and 63 and the amount of swing of the middle frame 20 and the inner frame 22, the distance d between the second shaft Y and the cam follower 55, the first shaft P and the cam follower 65. And a constant speed cam is used for each of the cams 52 and 63.

  The constant velocity cam is a cam in which the rotation angle and the displacement amount of the cam follower contacting the cam surface maintain a linear relationship, and has a cam surface as shown in FIG. Although the cam 52 is shown in FIG. 6, the cam 63 is exactly the same. While the cam surface rotates from the start point 52a to the end point 52b, the cam follower 55 is linearly displaced by a distance 2L. If the position of the cam surface when the cam follower 55 is located in the middle of the distance 2L is taken as the origin, as shown in FIG. 7, if the cam surface is rotated by an angle “−α” from the origin, the displacement of the cam follower 55 is “− If the cam surface rotates by an angle “α”, the displacement amount becomes “L”. In addition, a straight line is obtained by connecting the displacement points of the cam follower 55 at an arbitrary angular position. The displacement amount of the cam follower 55 corresponds to the swing amount of the middle frame 20 around the second axis Y, and the swing angle of the middle frame 20 necessary for camera shake correction is often in seconds, and even when it is large. Since it is about 1 ° at most, the rotation angle of the cam 52, that is, the rotation angle of the stepping motor 36 may be determined in proportion to the magnitude of the Y camera shake signal.

  In order to finely control the displacement amount of the cam follower 55, the number of rotation steps of the stepping motor 36 may be increased. However, the maximum swing angle of the middle frame 20 is set to ± 1.5 °, and the cam follower 55 at this time If the displacement amount is ± 0.2 mm, there is no practical problem if the number of rotation steps of the stepping motor 36 is 30 steps in the ± direction. In this case, the swing angle of the middle frame 20 per one-step rotation is about 3 minutes, and sufficient camera shake correction can be performed even in consideration of the imaging performance of the photographing lens 26 and the pixel pitch of the image sensor 27. In addition, a cam surface rotation angle of about ± 120 ° is sufficient.

  FIG. 8 is a block diagram showing an outline of a circuit configuration used together with the camera unit 12. The system controller 70 generally controls the operation of each circuit block via the bus line 71 and controls the operation of the digital camera. The image signal processing circuit 72 performs analog processing on the image signal output from the image sensor 27 and performs known image processing such as gamma correction and white balance adjustment. The image signal processed by the image signal processing circuit 72 is digitized by the AD converter 73 and input to the digital signal processing circuit 74. The digital signal processing circuit 74 performs digital interpolation processing, contour enhancement processing, and the like based on the input image data, and sends the image data to the bus line 71.

  When the camera mode is activated, the image sensor 27 continues to shoot, and image data obtained by the above processing is sequentially updated on the DRAM 75. Through images are sequentially displayed on the display panel 76 provided on the inner surface side of the receiver unit 4 by the image data sequentially read from the DRAM 75. While the through image is being displayed, the luminance of the photographed subject is monitored by the digital signal processing circuit 74, and a control signal for adjusting the charge accumulation time of the image sensor 27 is output so that the luminance is appropriate. To do. In response to this control signal, the system controller 70 operates the timing generator 77 to adjust the charge accumulation time of the image sensor 27. In addition, in order to give auxiliary illumination to the subject, it is also possible to turn on the LED 78 provided in the back of the illumination window 9 as necessary.

  The AF processing circuit 79 drives the stepping motor 79 a while calculating the integrated value of the contrast component of the subject image based on the digitized image data, and moves the focusing lens 26 a in the photographing lens 26. The integrated value of the contrast component of the subject image changes due to the movement of the lens 26a, but the stepping motor 79a is feedback-controlled so that this becomes a peak value, and when the peak value is reached, the stepping motor 79a is stopped to stop the lens 26a. Stops at the in-focus position.

  The HP sensors 59 and 68 are used to set the cams 52 and 63 constituted by constant velocity cams at the origin position shown in FIG. These HP sensors 59 and 68 detect whether or not the final stage gears of the first and second drive means are in the initial position, but the cams 52 and 63 are integrally formed with the final stage gear, Since the position coincides with the origin position of the cams 52 and 63, it is possible to check whether the cams 52 and 63 are set at the origin position by monitoring signals from the HP sensors 59 and 68. it can.

  The shake in the pitch direction of the casing 7 is detected by the sensor module 60P, and the shake in the yaw direction is detected by the sensor module 60Y. Each of these sensor modules 60P and 60Y outputs a high-speed responsive angular velocity sensor 80, an AD converter 81 that digitizes an analog output from the angular velocity sensor 80, and a camera shake signal corresponding to the signal from the AD converter 81. The P camera shake signal and the Y camera shake signal obtained from the camera shake amount detection circuit 82 are input to the P camera shake correction control circuit 38 and the Y camera shake correction control circuit 39 via the bus line 71, respectively. As described above, the camera shake correction control circuits 38 and 39 drive the stepping motors 35 and 36 in accordance with the input camera shake signals, respectively, and swing the camera unit 12 about the first axis P and the second axis Y. Move. The above-described camera shake correction control is performed after receiving a signal from the release switch 85 that is turned on by pressing the release button, and is not performed during the live view display period because the load on the built-in battery increases.

  When a release signal is input from the release switch 85, a still image is captured, and image data of the captured still image is stored in the flash memory 86. The image data stored in the flash memory 86 can be arbitrarily read and transferred to the memory card 6 and stored as necessary. The interface circuit 87 is used when image data stored in the flash memory 86 is transferred to a personal computer or displayed on a television monitor for observation.

  FIG. 9 shows processing when a still image is shot using the camera shake correction function of the apparatus of the present invention. When the mobile phone 2 is switched to the camera mode, the image sensor 27 is driven under the control of the system controller 70. Image signals sequentially output from the image sensor 27 are converted into image data via an image signal processing circuit 72, an AD converter 73, and a digital signal processing circuit 74, and are sequentially written in the DRAM 75. Image data is read from the DRAM 75 for each screen, and a through image is displayed on the display panel 76.

  During the live view display process, the digital signal processing circuit 74 measures the subject brightness based on the sequentially obtained image data, and sets the signal charge accumulation time by the image sensor 27 so that the appropriate brightness is obtained. Control to feedback type. Note that when an aperture is provided in the photographing optical system, it is possible to cope with not only adjustment of the accumulation time but also adjustment of the aperture opening. If the subject brightness does not reach a predetermined level even after making these adjustments, the auxiliary illumination LED 78 can be used automatically or by a user selection operation.

  After performing framing on the display panel 76, when a release button assigned to the function button of the mobile phone 2 is pressed and a release signal is input from the release switch 85, a photographing process is started. In response to the input of the release signal, the AF processing circuit 79 operates to execute AF processing, that is, focus the photographing lens 26 according to the contrast method. When the focusing process is completed, the sensor modules 60P and 60Y are activated to measure the shake applied to the housing 7, and output the P camera shake signal and the Y camera shake signal, respectively. The P camera shake correction control circuit 38 and the Y camera shake correction control circuit 39 calculate camera shake correction amounts according to the input P camera shake signal and Y camera shake signal, respectively. The correction amount calculated in this way corresponds to the number of rotation steps of the stepping motors 35 and 36, and thereby the stepping motors 35 and 36 are driven. The camera shake correction operation is started by driving the stepping motors 35 and 36. For example, when the housing 7 is shaken in the pitch direction for 30 seconds, the inner frame 22 is swung in the opposite pitch direction for 30 seconds, and the camera module 24 The photographing optical axis S is maintained in the direction immediately before the housing 7 is shaken.

  At this time, since the accumulation of signal charges by the image sensor 27 has not yet been started, the above-described camera shake operation is not necessary, but the sensor modules 60P and 60Y or the P camera shake correction control circuit 38, the Y camera shake correction control circuit 39, Furthermore, when there is a concern about response delay at the moment when the stepping motors 35 and 36 are activated, it is desirable to operate the camera shake correction device prior to the start of signal charge accumulation by the image sensor 27. Of course, if these response delays can be ignored, the camera shake correction device may be activated in synchronization with the start of signal charge accumulation in consideration of the consumption of the internal battery.

  In response to the signal from the timing generator 77, the image sensor 27 starts accumulating signal charges for still image shooting. Since the signal charge accumulation time during which the subject can be photographed with appropriate luminance has already been determined, the signal charge accumulation is continued until the accumulation end signal is input from the timing generator 77, and the handshake signal input by the sensor modules 60P and 60Y and The operations of the P camera shake correction control circuit 38 and the Y camera shake correction control circuit 39 based on the input camera shake signal and the operations of the stepping motors 35 and 36 are also continued. Therefore, even if the housing 7 shakes variously during the period until the signal charge accumulation time elapses, if the P camera shake signal and the Y camera shake signal are within ± 1.5 °, follow this. The inner frame 22 and the middle frame 20 are swung, and the photographing optical axis S of the camera module 24 is maintained in a certain direction.

  When the signal charge accumulation period ends, the shooting of the still image is completed. In synchronization with this, the operation of the sensor modules 60P and 60Y is stopped, the P camera shake correction control circuit 38 and the Y camera shake correction control circuit 39 are also turned off, and the camera shake correction operation ends. Thereafter, the process of returning the cams 52 and 63 to the origin position is performed, and one frame still image shooting process is completed. The origin position setting process for the cams 52 and 63 is performed by monitoring signals from the HP sensors 59 and 68 and returning the gears at the final stage to the initial positions.

  As described above, according to the present invention, the entire camera module 24 in which the photographing lens 26 and the image sensor 27 are integrated in accordance with the shake applied to the housing 7 during still image shooting. Since the camera module 24 only needs to be swung in the pitch direction or the yaw direction according to the amount of shake of the housing 7, the lens or image sensor can be moved according to hand shake as in the conventional case. Compared with the method of linear movement on the xy coordinate plane, the structure can be simplified, the correction accuracy can be improved, the manufacturing cost can be reduced, and the high-speed response can be obtained by shortening the arithmetic processing. it can. Along with this, even when shooting a dark scene where the signal charge accumulation time of the image sensor 27 is 1 to 2 seconds, it is possible to sufficiently follow the camera shake during that time, and there is also a correctable swing range. Up to about 1 ° to 2 ° can be secured with a margin.

  In carrying out the present invention, the components from the outer frame 18 to the inner frame 22 do not necessarily have to be rectangular cylinders. However, in order to simplify the structure and reduce the size, these components are used as in the embodiment. It is advantageous to arrange the first and second driving means using a flat surface of the rectangular cylinder, and in particular, arrange a plurality of gears constituting the gear train for reduction in a direction orthogonal to the photographing optical axis. By arranging them, it is possible to reduce the dimensions in the direction of the photographic optical axis, which is extremely effective for incorporating in a mobile phone having a thin casing itself.

  In supporting the camera module 24 so as to be swingable in the pitch direction and the yaw direction, the first axis and the second axis, which are the center of swing, do not necessarily intersect at one point on the photographing optical axis. However, if the amount of misalignment between both axes increases to a level that cannot be ignored, for example, the calculation for calculating the correction amount in the pitch direction and the correction amount in the yaw direction is not required. It can be dealt with by processing. Similarly, the distance from the cam follower 65 of the inner frame 22 to the first axis P and the distance from the cam follower 55 of the inner frame 20 to the second axis Y do not have to be exactly matched, and the difference becomes somewhat large. In such a case, it can be dealt with by arithmetic processing. Further, the first axis and the second axis need only be orthogonal to each other, and these axes do not necessarily have to coincide with a vertical line or a horizontal line.

  Although a pair of angular velocity sensors for detecting camera shake can be assembled to the casing 7 itself, the sensor modules 60P and 60Y together with these angular velocity sensors 80 are assembled to the outer frame 18, and the stepping motors 35 and 36 and P camera shake are combined. By assembling the correction control circuit 38 and the Y camera shake correction control circuit 39 to the outer frame 18 and the middle frame 20, respectively, the camera module 24 and the entire camera shake correction device can be combined as one camera unit 12, and the housing 7 can also be simplified. Furthermore, since the device according to the present invention is a method of swinging the entire camera module 24 in response to camera shake of the housing 7, it is not affected at all by the focal length of the photographing lens 26. Therefore, even when the photographic lens 26 is composed of a zoom lens, camera shake correction can be performed without considering any zoom magnification, and it can be widely applied to general digital cameras equipped with a zoom lens. It is.

1 is an external view of a mobile phone using the present invention. It is principal part sectional drawing of the mobile telephone shown in FIG. It is an external view of a camera unit using the present invention. It is a block diagram of a camera shake correction control circuit. It is a disassembled perspective view of a camera unit. It is explanatory drawing of a constant velocity cam. It is a graph which shows the relationship between the rotation angle and displacement amount of a constant velocity cam. It is a block diagram which shows the circuit structure used with a camera unit. 6 is a flowchart of still image shooting processing using a camera shake correction function together.

Explanation of symbols

2 Mobile phone 12 Camera unit 18 Outer frame 20 Middle frame 22 Inner frame 24 Camera module 26 Shooting lens 27 Image sensor 30, 62 Holding plate 45, 46 Torsion spring 52, 63 Cam 55, 65 Cam follower

Claims (8)

  A camera module in which a photographic lens and an image sensor are integrated is housed in a housing, and the camera module is swung around a first axis and a second axis perpendicular to the photographic optical axis and perpendicular to each other. Attaching freely to the housing, and correcting the camera shake during still image shooting by controlling the posture of the entire camera module inside the housing according to the shake of the housing detected by a camera shake sensor. A camera shake correction device featuring the camera. An inner frame that supports the inner frame to which the camera module is fixed from the outside so as to be swingable around the first axis;
An outer frame fixed to the casing and supporting the middle frame from the outside so as to be swingable around the second axis;
First driving means incorporated in either the inner frame or the middle frame, and swinging the inner frame about the first axis in response to a camera shake signal from the camera shake sensor;
2. A second drive unit that is incorporated in either the middle frame or the outer frame and swings the middle frame around a second axis in accordance with a camera shake signal from the camera shake sensor. 1. A camera shake correction apparatus for a camera according to 1.   The first drive means is assembled to the inner frame, and the second drive means is assembled to the outer frame. These drive means rotate integrally with the stepping motor, the reduction gear train that reduces the rotation of the stepping motor, and the final gear. 3. The camera shake correction device for a camera according to claim 1, further comprising a cam for swinging the inner frame and the middle frame via cam followers provided on the inner frame and the middle frame, respectively.   The middle frame and the outer frame are formed of a rectangular cylinder that surrounds the imaging optical axis, and a plurality of gears that form the reduction gear train are arranged on one side of each rectangular cylinder in a direction substantially orthogonal to the imaging optical axis. The camera shake correction device for a camera according to claim 3.   The stepping motor, the reduction gear train, and the cam that constitute the first and second driving means are common parts to each other, and are respectively assembled to the inner frame and the outer frame by holding plates having the same shape. The camera shake correction device for a camera according to claim 4.   6. The camera shake correction apparatus according to claim 3, wherein the cam is a constant velocity cam.   7. The camera shake correction device for a camera according to claim 6, wherein a maximum diameter of the cam is equal to or less than an outer diameter of a gear shaft formed integrally with the gear in the final stage. 8. A camera shake correction apparatus for a camera according to claim 5, wherein a pair of camera shake sensors for detecting camera shake around the first axis and the second axis are assembled to the outer frame. .

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