JP2011154104A - View angle center deviation correction device and view angle deviation correction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a view angle center deviation correction device that reduces view angle deviation in a digital camera including a collapsible zoom lens unit. <P>SOLUTION: The view angle center deviation correction device includes: the collapsible zoom lens unit (3) including a plurality of zoom lenses arranged along an optical axis; an imaging system (2) for continuously imaging images by an imaging device via the zoom lenses; a zoom control section (26) for setting zoom magnification; a zoom drive section (28) for moving each zoom lens based on the set zoom magnification; a blur detecting section (24) for detecting an amount of blur generated in the imaging system (2); and an imaging device control section (25) performing a zoom correction operation in which the deviation of an optical axis is corrected according to the zoom magnification, and a hand shake correction operation in which the blur of a subject image is corrected, thereby moving the imaging device (7) in a predetermined direction, and thereby correcting the deviation of the optical axis. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an angle-of-view center misalignment correcting apparatus and an angle-of-view center misalignment correcting method for correcting a misalignment of an optical axis in a digital camera including a retractable zoom lens unit.

  In recent years, a lens-integrated camera capable of moving image shooting and continuous shooting using a high-magnification retractable zoom lens unit has been developed. In a camera equipped with a retractable zoom lens unit, when the zoom operation is performed from the wide-angle end to the telephoto end, or from the telephoto end to the wide-angle end, the zoom lens unit is caused by the weight of the zoom lens constituting the retractable zoom lens unit. In some cases, the tilt and the angle of view were shifted.

  Such a shift in the angle of view can be corrected by the photographer performing readjustment of the shooting range after zooming to an arbitrary zoom level. For this reason, no practical problem has occurred during still image shooting. However, at the time of moving image shooting, an image at the time of readjusting the shooting range in order to correct the deviation of the angle of view is also shot and remains as a moving image. For this reason, the problem of the displacement of the retractable zoom lens unit field angle cannot be ignored during moving image shooting.

  In a digital camera having a retractable zoom lens unit, the optical axis may be shifted due to the step of the cam groove in the zoom mechanism. When moving the zoom lens, there is a digital camera that corrects the deviation of the optical axis due to the step of the cam groove in accordance with the position of the zoom lens (see, for example, Patent Document 1).

JP 2006-330540 A

  Particularly, in a digital camera having a retractable zoom lens unit, the zoom lens unit tends to tilt due to mechanical factors such as the weight of the lens. In a conventional digital camera, particularly for a digital camera having a retractable zoom lens unit, in which the zoom lens unit is easily tilted due to mechanical factors of the zoom lens, etc., the field angle deviation is corrected effectively and efficiently. There was nothing.

  As shown in FIG. 7, a digital camera having a conventional retractable zoom lens unit generally includes a zoom lens unit 103 including a plurality of zoom lenses 103a, 103b, and 103c, and an image sensor 107.

In such a digital camera, as shown in FIG. 7 (1), zoom lenses 103a, 103b, and 103c are accommodated when shooting at the wide-angle end. Therefore, the zoom lens unit 103 is caused by the weight of the zoom lenses 103a, 103b, and 103c. There is little inclination. For this reason, since it is possible to maintain a state in which the optical axis 141 of the digital camera is directed to the center point C ₁ of the image sensor 107, the image of the subject 201 is the center point C of the image sensor 107 to which the optical axis 141 is directed. _The image is formed with ₁ as the center. As a result, it is possible to obtain an image of matches in angle 200 around the point PC ₁ an image of a subject 201. As described above, when the zoom magnification is low, the center deviation of the angle of view 200 is unlikely to occur. Therefore, a captured image in which the image of the subject 201 is stored in the center PC _{1 of the} angle of view 200 is easily obtained.

On the other hand, as shown in FIG. 7 (2), when taking a picture at the telephoto end, the zoom lenses 103a, 103b, 103c are extended, so that the zoom lens unit 103 is tilted by the weight of the zoom lenses 103a, 103b, 103c. . For this reason, the state in which the optical axis 141 of the digital camera is directed to the center point C ₁ of the image sensor 107 cannot be maintained, and the point where the optical axis 141 hits the image sensor 107 is the center point C of the image sensor 107. It deviates from ₁ to another point _{C 2.} For this reason, the image of the subject 201 is formed in the image sensor 107 around the point C ₂ where the optical axis 141 hits, not the center point C ₁ of the image sensor 107. As a result, the image of the subject 201 being imaged no longer fit into the angle of view 200 centered on the point PC _1. As described above, when the zoom magnification is high, the center of the angle of view 200 is likely to be misaligned, and thus there is a problem that the angle of view of the photographed image is deviated particularly during movie shooting or continuous shooting. It was.

  The present invention has been made in view of the above-described conventional problems, and in a digital camera including a retractable zoom lens unit, an angle-of-view center correction apparatus and an angle of view that can reduce the angle-of-view displacement. An object of the present invention is to provide a center misalignment correction method.

  An angle-of-view center correction apparatus according to a first aspect of the present invention includes a collapsible zoom lens unit including a plurality of zoom lenses arranged along an optical axis, and an image by an imaging device via the plurality of zoom lenses. An image pickup means for continuously picking up images, a zoom magnification setting means for setting a zoom magnification, a zoom means for moving each zoom lens based on the zoom magnification set by the zoom magnification setting means, and the imaging means A blur detection unit that detects a blur amount generated in the optical axis, and an optical axis correction unit that corrects a deviation of the optical axis by moving the imaging element in a predetermined direction. The optical axis correction unit includes the zoom magnification. A zoom correction operation for correcting the deviation of the optical axis according to the zoom magnification set by the setting means, and the image pickup device according to the blur amount detected by the blur detection means. Characterized in that and performing a shake correction operation for correcting the shake of the object image, selectively.

  The field angle center deviation correction apparatus according to the second aspect of the present invention provides a correction mode in which the optical axis correction unit corrects a deviation of the optical axis, and the optical axis correction unit performs the zoom correction operation according to a shooting situation. And a correction mode setting unit that sets the zoom correction mode to be performed and the camera shake correction mode in which the optical axis correction unit performs the camera shake correction operation.

  In the angle-of-view center correction apparatus according to the third aspect of the present invention, the optical axis correction unit performs the zoom correction operation when the camera shake correction mode is set by the correction mode setting unit. And only the camera shake correction operation is performed.

  According to a fourth aspect of the present invention, there is provided an angle-of-view center correction device for setting a monitoring mode for photographing while changing a zoom magnification of the zoom magnification setting means by remote control while a digital camera is fixed. When the monitoring mode is set by the monitoring mode setting means, the optical axis correction means performs only the zoom correction operation without performing the camera shake correction operation.

  The field angle center misalignment correction apparatus according to the fifth aspect of the present invention is a relation data storage for storing relation data indicating a relation between a zoom magnification set by the zoom magnification setting means and a correction amount corresponding to the zoom magnification. And a correction amount determination unit that determines a correction amount when the optical axis correction unit performs the zoom correction operation based on the relationship data stored in the relationship data storage unit. To do.

  A field angle center misalignment correction apparatus according to a sixth aspect of the present invention is a change in which the relationship data indicating a relationship between the zoom magnification stored in the relationship data storage means and the correction amount is changed manually or automatically. Means are provided.

  An angle-of-view center correction apparatus according to a seventh aspect of the present invention includes a determination mode setting unit that sets an automatic determination mode for determining the relational data, and the automatic determination mode is set by the determination mode setting unit. Further, while changing the zoom magnification set by the zoom magnification setting means, the image pickup means picks up an image a plurality of times through the plurality of zoom lenses, and the image pickup means for each zoom magnification. A deviation amount detecting means for detecting a deviation amount of the captured image by image analysis, and a correction amount corresponding to the zoom magnification based on the deviation amount detected by the deviation amount detecting means are shown. And relation data determining means for determining the relation data.

  In the angle-of-view center correction apparatus according to the eighth aspect of the present invention, the optical axis correction unit determines a moving speed of the image sensor 7 according to a speed at which the imaging unit continuously captures images. It is characterized by.

  An angle-of-view center shift correcting apparatus according to a ninth aspect of the present invention is characterized by comprising power-on setting means for automatically setting the relational data stored in the relational data storage means at power-on.

  An angle-of-view center correction apparatus according to a tenth aspect of the present invention is provided in a digital camera.

  According to an eleventh aspect of the present invention, there is provided a displacement correction method for correcting a displacement of an optical axis by a field angle center displacement correction device having a retractable zoom lens unit including a plurality of zoom lenses arranged along the optical axis. A correction method, wherein the deviation correction method includes an imaging step of continuously capturing images with an imaging element via the plurality of zoom lenses, a zoom magnification setting step for setting a zoom magnification, and the zoom magnification setting step. A zoom step for moving each zoom lens based on the zoom magnification set by the step, a blur detection step for detecting a blur amount occurring between the plurality of zoom lenses and the image sensor, An optical axis correction step that corrects a deviation of the optical axis by moving in the direction of the optical axis, the optical axis correction step comprising: A zoom correction operation that corrects the deviation of the optical axis in accordance with the zoom magnification set in the rate setting step, and a blur in the subject image captured by the image sensor in accordance with the blur amount detected in the blur detection step. The camera shake correction operation is selectively performed.

  According to the present invention, in a digital camera including a retractable zoom lens unit, it is possible to reduce the angle of view.

It is a figure which shows the front and back surface of the digital camera which concerns on one embodiment of this invention. It is a block diagram of the digital camera of FIG. It is a figure which shows schematic operation | movement of the displacement correction | amendment performed by the angle-of-view center displacement correction apparatus mounted in the digital camera of FIG. It is a figure which shows the flowchart of the imaging | photography process performed by the angle-of-view center deviation correction apparatus mounted in the digital camera of FIG. It is a figure which shows the flowchart of the calibration process performed by the angle-of-view center deviation correction apparatus mounted in the digital camera of FIG. It is a figure explaining the example of imaging | photography with the digital camera of FIG. It is a figure explaining the example of imaging | photography with the conventional digital camera.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(1) First embodiment

  FIG. 1 is a block diagram showing an external appearance of a digital camera 1 that is an embodiment of a digital camera provided with an angle-of-view center shift correcting device according to an embodiment of the present invention. FIG. 1 is a rear view of the digital camera 1. FIG.

  As shown in FIG. 1A, the digital camera 1 has a zoom lens unit 3 that constitutes an imaging system 2 (see FIG. 2) on the front side of the housing 10 of the digital camera 1. Further, as shown in FIG. 1 (2), a display monitor 33, a changeover switch 12 constituting an operation unit 35 (see FIG. 2), and a camera shake correction function key 13 are provided on the rear surface of the housing 10 of the digital camera 1. In addition, a mode setting dial 14 for determining shooting conditions, a cursor key 15, a zoom key 16 (W (wide angle) button 16a, T (telephoto) button 16b), and the like are provided. A shutter key 17 and a power switch 18 are provided on the upper surface of the housing 10 of the digital camera 1, and a side portion of the housing 10 is used for connection with an external device such as a personal computer (hereinafter referred to as a personal computer) or a modem. A USB terminal connection unit used when connecting to a USB cable is provided.

  FIG. 2 is a block diagram for explaining the configuration of the control circuit of the digital camera 1 according to the embodiment of the present invention.

  The digital camera 1 includes an imaging system 2, an angle-of-view center correction device 5, an imaging element driving unit 27, a zoom driving unit 28, a timing generation unit 29, a signal processing unit 30, an image processing unit 31, a display processing unit 32, and a display monitor. 33, a recording unit 34, an operation unit 35, and a camera control unit 36. The angle-of-view center deviation correction device 5 includes a deviation amount detection unit 22, a relational data storage unit 23, and a shake detection unit 24. The camera control unit 36 includes an image sensor control unit 25 and a zoom control unit 26.

  The imaging system 2 is disposed on a retractable zoom lens unit 3 constituted by three zoom lenses 3a, 3b, and 3c, a focus lens 4 corresponding to the zoom lens unit 3, an image sensor correction stage 8, and an image sensor correction stage 8. It has an image sensor 7 provided. The zoom lenses 3a, 3b, 3c constituting the zoom lens unit 3 have an optical axis 41, and are driven forward and backward along the optical axis 41 by a zoom control unit 26 described later. The focus lens 4 is driven back and forth in the direction of the optical axis 41 by a focus control mechanism. The focus adjustment of the imaging system 2 is performed by driving the focus lens 4 forward and backward. Further, when the zoom lenses 3a, 3b, and 3c are driven forward and backward, the position at which the optical axis 41 of the zoom lenses 3a, 3b, and 3c hits the image sensor 7 is slightly changed due to the weight of the zoom lenses 3a, 3b, and 3c. .

  The image sensor correction stage 8 is formed in a flat plate shape. The image pickup device correction stage 8 is driven by the image pickup device driving unit 27, and the image pickup device 7 is moved and adjusted so that the center of the image pickup device 7 coincides with the position where the optical axis 41 is incident. An image can be formed on the imaging surface of the element 7. A zoom correction operation for correcting a shift of the optical axis 41 according to a zoom magnification set by a zoom control unit 26 described later, and a subject imaged by the image sensor 7 according to a blur amount detected by the blur detection unit 24 The principle of the camera shake correction operation for correcting image blur is that a zoom operation or fluctuation of the optical axis 41 due to the occurrence of camera shake drives the image sensor correction stage 8 so that the center of the image sensor 7 is at the center of the zoom lens 3a. , 3b, 3c is absorbed by adjusting the movement of the image sensor 7 so that the optical axis 41 coincides with the position incident on the image sensor 7. Therefore, in the present embodiment, zoom correction and camera shake correction are performed by optical axis correction or optical axis correction operation.

  The camera control unit 36 constitutes a correction mode setting unit that sets one of a zoom correction mode for performing a zoom correction operation according to a shooting situation and a camera shake correction mode for performing a camera shake correction operation. In addition, the camera control unit 36 constitutes a switching unit that switches between performing a zoom correction operation or a shake correction operation by the image sensor control unit 25 according to the set correction mode. Specifically, when the camera shake correction mode is selected by the user's operation of the operation unit 35, the image pickup device control unit 25 switches to the camera shake correction operation, and when the zoom correction mode is selected, the zoom is corrected. Switch to correction operation. When the camera shake correction mode is selected, only the camera shake correction operation is performed without performing the zoom correction operation. The optical axis shift can be corrected by switching between the zoom correction operation and the blur correction operation by one image sensor control unit 25 without creating a new correction device. Therefore, the digital camera 1 according to the present embodiment can reduce the angle of view displacement caused by using the retractable zoom lens unit 3 without complicating the apparatus.

  In addition, the camera control unit 36 constitutes a changing unit that manually or automatically changes the relationship data indicating the relationship between the zoom magnification stored in the relationship data storage unit 23 and the correction amount. Specifically, when the power switch 18 is operated by the user and the power of the digital camera 1 is turned on, the camera control unit 36 is set to the automatic determination mode and automatically executes a calibration process to be described later. The relation data stored in the relation data storage unit 23 is changed to the latest relation data. Therefore, the user can always perform the zoom correction operation in the latest and optimum state without paying particular attention to the deviation of the optical axis. For this reason, a user's burden with respect to an optical axis shift is reduced. Further, the camera control unit 36 can manually change the relational data by the operation of the operation unit 35 by the user. This makes it possible to perform optical axis misalignment correction according to the preference of an advanced user who desires to make fine settings for imaging conditions. As a result, it is possible to reflect the detailed intention of the user with respect to the optical axis deviation. In addition, the camera control unit 36 constitutes a monitoring mode setting unit that sets a monitoring mode for performing photographing while changing the zoom magnification of the zoom control unit 26 by remote operation with the digital camera 1 fixed. When the monitoring mode is set by the camera control unit 36, the image sensor control unit 25 performs only the zoom correction operation without performing the camera shake correction operation. In addition, the camera control unit 36 constitutes a determination mode setting unit that sets an automatic determination mode for automatically determining the relationship data stored in the relationship data storage unit 23. In the present embodiment, when the power switch 18 is operated by the user and the power of the digital camera 1 is turned on, the camera control unit 36 is set to the automatic determination mode, executes a calibration process, and stores related data. It is assumed that the relational data stored in the unit 23 is automatically determined, but it is desirable to execute this calibration process with the camera fixed using a tripod or the like.

  The image sensor 7 is constituted by a CCD, a CMOS, or the like. The image sensor 7 captures a subject image formed on the imaging surface and outputs an image signal. The signal processing unit 30 performs predetermined signal processing (for example, color interpolation processing, γ correction processing, white balance processing, shading correction processing, etc.) after converting the analog imaging signal into a digital signal. The timing generation unit 29 generates a read timing signal for an image pickup signal read from the image sensor 7.

  The zoom lenses 3a, 3b, 3c, the focus lens 4 and the image sensor 7 constituting the zoom lens unit 3 are arranged such that the optical axes 41 of the incident light are substantially coincident with each other.

  As shown in the calibration process described later with reference to FIG. 5, the deviation amount detection unit 22 is operated automatically by the camera control unit 36 by the user operating the power switch 18 to turn on the main power of the digital camera 1. When the determination mode is set, a plurality of zoom lenses 3a, 3b, and 3c are extended for each zoom stage while changing the zoom magnification set by the zoom control unit 26, and moving image shooting and continuous shooting are performed by the image sensor 7. An image is captured a plurality of times by shooting, and the amount of deviation of the image captured at each zoom magnification is detected by image analysis (calibration process). The deviation amount detection unit 22 constitutes a deviation amount detection unit according to the present embodiment.

  The relationship data storage unit 23 stores relationship data indicating the relationship between the zoom magnification set by the zoom control unit 26 and the correction amount corresponding to the zoom magnification. The relational data storage unit 23 constitutes relational data storage means according to this embodiment. Specifically, in the calibration process described with reference to FIG. 5 to be described later, the optical axis correction corresponding to the current zoom magnification is performed based on the shift amount of the center of the angle of view between each image obtained for each zoom magnification. Remember as a quantity.

  The blur detection unit 24 physically and directly detects the motion of the digital camera 1 and outputs a motion detection signal indicating the angular velocity to the camera control unit 36. The blur detection unit 24 is activated upon receiving a correction start command from the camera control unit 36, functions as a blur detection unit using a gyroscope, an angular velocity sensor, or the like, and detects a blur amount generated in the digital camera 1.

  The image sensor control unit 25 is activated upon receiving a correction start command from the camera control unit 36, and in accordance with the zoom magnification controlled by the zoom control unit 26 based on the relationship data stored in the relationship data storage unit 23. A correction amount is calculated, a signal for driving the image sensor correction stage 8 is output to the image sensor driving unit 27 based on the calculated correction amount, and a zoom correction operation is performed. Further, the image sensor control unit 25 has a conversion table for outputting a blur amount corresponding to the magnitude of the detection signal from the blur detection unit 24 as a correction amount. The image sensor control unit 25 calculates a correction amount according to the detection signal detected by the blur detection unit 24, and a signal for driving the image sensor correction stage 8 to the image sensor driving unit 27 based on the calculated correction amount. Is output and shake correction is performed. That is, the camera control unit 36 constitutes an optical axis correction unit according to the present embodiment that corrects the deviation of the center of the field angle of the captured image captured by the image sensor 7.

  The image sensor drive unit 27 causes the image sensor 7 arranged on the image sensor correction stage 8 according to the correction amount from the camera control unit 36 to be orthogonal to the optical axes 41 of the zoom lenses 3 a, 3 b, 3 c and the focus lens 4. Then, the image sensor correction stage 8 is moved. Note that the amount of movement of the image sensor 7 disposed on the image sensor correction stage 8 is determined according to the zoom magnification set by the zoom control unit 26 or the amount of blur detected by the blur detection unit 24.

  The image processing unit 31 converts the format of the image data input from the signal processing unit 30 into a predetermined data format, or gives the image data to the display processing unit 32. The display processing unit 32 generates a video signal using the image data and sends it to the display monitor 33.

  The display monitor 33 is configured by a liquid crystal display panel or the like, and displays an image or the like based on a video signal input from the display processing unit 32. The display image is recorded in the recording unit 34, a through image that is sequentially captured by the image sensor 7 before the still image capturing instruction, a still image that is captured by the image sensor 7 after the still image capturing instruction, a moving image at the time of moving image capturing, and the like. There are playback images based on image data. These images can be displayed on the display monitor 33 by electrically changing the display angle of view (electronic zoom) by operating the operation unit 35.

  The recording unit 34 is configured by a removable memory card or the like. In the shooting mode, the recording unit 34 records the image data whose format has been converted by the image processing unit 31. In the reproduction mode, the image data recorded in the recording unit 34 is read and sent to the image processing unit 31. The image processing unit 31 generates a video signal for displaying a reproduced image. The digital camera 1 is configured to be able to select each of a still image shooting mode, a continuous shooting still image shooting mode, and a moving image shooting mode, and audio data may be recorded during moving image shooting.

  The operation unit 35 includes a power switch 18 (main switch), a zoom key 16, a mode setting dial 14, a shutter key 17 (half-press switch, full-press switch), and the like, and the shooting conditions of the digital camera 1 according to the present embodiment. An operation signal is generated based on an operation condition corresponding to each operation and is sent to the camera control unit 36. Thereby, for example, when the zoom switch is operated by the operator, a predetermined magnification (for example, 1 to 12 times) is set as the photographing condition.

  The camera control unit 36 includes a CPU and a ROM that stores a control program executed by the CPU and a work RAM (not shown), and outputs commands to each block in response to an operation signal input from the operation unit 35. And control the camera operation.

<Description of imaging system>
Referring to FIG. 3, the operation when the image sensor 7 is moved by driving the image sensor correction stage 8 by the field angle center deviation correction apparatus 5 according to the present embodiment to correct the image angle center deviation. explain.

  As shown in FIG. 3, the zoom lenses 3a, 3b, 3c, the focus lens 4 and the image pickup device 7 constituting the zoom lens unit 3 are arranged in a line along an optical axis 41 facing an image pickup target (not shown). They are arranged side by side. The image sensor 7 is fixedly connected to the image sensor correction stage 8.

  Further, the position at which the optical axis 41 of each zoom lens 3a, 3b, 3c constituting the zoom lens unit 3 of the digital camera 1 enters the image sensor 7 and the center C of the image sensor 7 coincide. Assuming that the optical axis 41 is directed to the center of the subject to be imaged, when the shutter key 17 is pressed and the shutter is opened in this state, the center position of the subject image formed on the image sensor 7 and the center of the image sensor 7 are displayed. It will coincide with the position of C. Therefore, the subject falls within the center of the angle of view of the captured image. On the other hand, when the zoom control unit 26 increases the zoom magnification, if nothing is done, each time the zoom magnification increases due to mechanical factors such as the weight of the zoom lenses 3a, 3b, 3c, the zoom lenses 3a, 3b, 3c The optical axis 41 fluctuates, and the position of the center of the subject image formed on the image sensor 7 deviates from the center C of the image sensor 7.

  Therefore, in the angle-of-view center correction apparatus 5 according to the present embodiment, when the zoom control unit 26 detects that zooming at a predetermined magnification has been performed, the camera control unit 36 fixes the image sensor 7. The connected image sensor correction stage 8 is moved in the X and Y directions by the amount of fluctuation of the optical axis 41 of the zoom lenses 3a, 3b, 3c based on the correction amount stored in the relational data storage unit 23 ( The position where the optical axis 41 is incident on the image sensor 7 and the center C of the image sensor 7 are always matched.

  Further, in the angle-of-view center correction device 5 according to the present embodiment, when the predetermined blur amount is detected by the blur detection unit 24, the camera control unit 36 is connected to the image sensor 7 fixedly. The light from the zoom lenses 3a, 3b, 3c is moved (shifted) in the X and Y directions based on the correction amount calculated according to the detection signal detected by the blur detection unit 24. A camera shake correction operation for correcting the blur of the subject image with respect to the center of the angle of view is performed so that the position where the axis 41 is incident on the image sensor 7 and the center C of the image sensor 7 always coincide.

  As described above, the image angle center misalignment correction apparatus 5 increases the zoom magnification of the digital camera 1 so that the imaging element correction stage 8 causes the imaging element even if the optical axis 41 of the zoom lenses 3a, 3b, and 3c changes. By shifting 7, the center position of the subject image formed on the image sensor 7 is corrected so as to coincide with the center C of the image sensor 7. Therefore, the center position of the subject image formed on the image sensor 7 is corrected. Does not deviate from the center C of the image sensor 7. Therefore, the angle-of-view center correction device 5 can reduce not only the blur correction of the subject image but also the angle-of-view center shift during the zoom operation.

<Shooting process>
FIG. 4 is a flowchart for explaining a photographing process of the digital camera 1 provided with the angle-of-view center deviation correcting device 5 according to the present embodiment. The processing shown below may basically be executed by the camera control unit 36 according to a program stored in advance in a program memory such as a flash memory. Hereinafter, description will be given based on the flowchart shown in FIG. Hereinafter, the digital camera is described as having an autofocus function, but the present invention is not limited to this.
In this photographing process, in addition to the processes shown in FIG. 4, processes such as imaging control, exposure control, focus control, and recording control are executed in parallel. Here, mainly, zoom control and camera shake correction control are performed. The processing part including the optical axis correction control will be described.

When the user operates the power switch to turn on the main power of the digital camera 1 and the user operates the operation unit 35, the photographing process shown in FIG. 4 is started.
First, the camera control unit 36 determines whether there is an instruction to change the zoom magnification based on a signal from the operation unit 35 (step S11). In this process, it is determined whether or not a zoom operation has been performed by an operation from the operation unit 35 of the user. If there is an instruction to change the zoom magnification, the process proceeds to step S12. If there is no instruction to change the zoom magnification, the process of step S11 is repeated until there is an instruction to change the zoom magnification.

  Next, in step S12, the extension distance of the zoom lens unit 3 is changed so that the instructed zoom magnification is obtained. In this process, when there is an instruction to change the zoom magnification to the telephoto end side, the extension distance between the zoom lenses 3a, 3b, 3c constituting the zoom lens unit 3 is lengthened, and the zoom is performed. When there is an instruction to change the magnification to the wide angle end side, the extension distance between the zoom lenses 3a, 3b, 3c constituting the zoom lens unit 3 is shortened.

  Next, in step S13, the camera control unit 36 determines whether or not the camera shake correction mode is set as the current correction mode. In this process, the camera shake correction mode is set by the user's operation of the operation unit 35, and it is determined whether or not the camera shake correction mode is started. If it is determined in step S13 that the camera shake correction mode is set, the process proceeds to step S14. If it is determined that the camera shake correction mode is not set, the process proceeds to step S16. move on.

  In step S <b> 14, the blur detection unit 24 detects the blur amount generated in the digital camera 1 and outputs it to the camera control unit 36. Next, in step S <b> 15, the camera control unit 36 changes the position of the image sensor 7 according to the shake amount detected by the shake detection unit 24. In this processing, the image sensor control unit 25 of the camera control unit 36 drives the image sensor correction stage 8 in accordance with the amount of blur by an actuator provided in the image sensor drive unit 27 so as to cancel the camera shake. adjust. Specifically, as described with reference to FIG. 3, the image sensor control unit 25 controls the image sensor 7 so that the position where the optical axis 41 enters the image sensor 7 and the center C of the image sensor 7 coincide. Move. In this way, the camera shake correction operation for correcting the blur of the subject image is performed. When this process ends, the process proceeds to step S20.

  In step S16, the camera control unit 36 determines whether the monitoring mode is set. In this process, it is determined whether or not the monitoring mode is started by the operation of the user operation unit 35. If it is determined that the monitoring mode is started, the process proceeds to step S17, and the monitoring mode is started. If it is determined that has not started, the process proceeds to step S20.

  Next, in step S17, the camera control unit 36 determines whether or not the current shooting mode is moving image shooting or continuous shooting. In this process, it is determined whether or not moving image shooting or continuous shooting has been started by the user's operation of the operation unit 35, and if it is determined that moving image shooting or continuous shooting has been started, step The process proceeds to step S18, and if it is determined that neither moving image shooting nor continuous shooting is started, the process proceeds to step S20.

  Next, in step S18, the camera control unit 36 specifies the correction amount of the optical axis 41 according to the instructed zoom magnification. In this process, the camera control unit 36 refers to the relationship data stored in the relationship data storage unit 23 and performs a process of specifying the correction amount according to the zoom magnification.

  Next, in step S <b> 19, the camera control unit 36 changes the position of the image sensor according to the specified correction amount of the optical axis 41. In this process, the image sensor control unit 25 of the camera control unit 36 drives the image sensor correction stage 8 according to the amount of blur by an actuator provided in the image sensor drive unit 27 so as to cancel out camera shake. Adjust. Specifically, as described with reference to FIG. 3, the image sensor control unit 25 controls the image sensor 7 so that the position where the optical axis 41 enters the image sensor 7 and the center C of the image sensor 7 coincide. Move. In this way, the image sensor 7 can be driven by the actuator provided in the image sensor drive unit 27 so that the center deviation of the angle of view is reduced. Therefore, the zoom correction that corrects the deviation of the optical axis according to the zoom magnification. The action can be performed. Furthermore, in order to reduce the influence on the captured image, the speed at which the image sensor 7 is moved at the time of zoom correction is set to the shooting speed when performing moving image shooting or continuous shooting, for example, the number of frames per second. It is preferable to determine in consideration of the above. Thus, zoom correction can be performed without affecting moving image shooting or continuous shooting.

  Thereby, when the camera shake correction mode is set, only the camera shake correction operation can be performed without performing the zoom correction operation performed in steps S18 to S19. On the other hand, when the monitoring mode is set, only the zoom correction operation is performed without performing the camera shake correction operation performed in steps S14 to S15. Therefore, there is no need to provide a separate configuration, and the correction operation can be switched by using the same image sensor driving unit 27 according to the shooting conditions. Accordingly, it is possible to simplify the parts and reduce the manufacturing cost. In addition, when one optical axis correction operation is performed, the other optical axis correction operation is not performed. Therefore, at the time of photographing with the digital camera 1, two optical axis corrections, a zoom correction operation and a camera shake correction operation, are performed. Each optical axis correction operation can be performed independently without the operations affecting each other. Therefore, a highly accurate optical axis correction operation can be performed.

  Next, in step S20, the camera control unit 36 determines whether or not shooting has been completed. In this process, when the operation of the operation unit 35 by the user is not performed for a certain period of time, or when it is determined that shooting has been completed because the power switch is operated by the user and the main power supply of the digital camera 1 is set to OFF. If it is determined that the shooting process has ended and the shooting has not ended, the process returns to step S11, and the processes of steps S11 to S20 are repeated.

<Calibration process>
FIG. 5 is a flowchart for explaining the calibration process of the digital camera 1 provided with the angle-of-view center shift correcting device 5 of the present invention. It is assumed that the calibration process shown in FIG. 5 is executed before the photographing process shown in FIG.
Note that this calibration process is preferably performed with the camera fixed on a tripod, so that a message “Please fix the camera with a tripod” is output at the start of the calibration process. May be. Also, whether the camera is fixed or not is determined based on the detection state of the switch provided on the tripod mounting section or the detection state of the camera movement by a gyro sensor. A message may be output when it is determined.

  First, when the user operates the power switch to turn on the main power of the digital camera, an ON / OFF operation signal corresponding to the user's operation is input to the operation unit 35. At this time, since the operation unit 35 generates an interrupt signal and outputs it to the camera control unit 36, the camera control unit 36 sets a flag indicating the operation content in an ON / OFF setting flag area of a memory (not shown).

  In FIG. 5, in step S31, the camera control unit 36 checks the ON / OFF setting flag area set by the operation unit 35, and determines whether or not the power is set to ON. If the camera control unit 36 determines that the power source is not set to ON, it repeats the process of step S31 until the power source is set to ON, and if it is determined that the power source is set to ON. Performs the process of step S32.

  Next, in step S <b> 32, the camera control unit 36 gives a signal to the zoom control unit 26, drives the zoom drive unit 28, sets the zoom magnification of the zoom lens unit 3 to the wide angle end, and sets the zoom lens unit 3. Initialize the feeding distance. In this process, the feeding distance between the zoom lenses 3a, 3b, 3c constituting the zoom lens unit 3 is shortened, and the calibration process is initialized.

Next, in step S33, the camera control unit 36 captures an image at the wide-angle end and stores an image A ₀ (not shown). In this process, in order to initialize the calibration process, imaging is performed with the zoom lens unit 3 set at the wide-angle end with the lowest zoom magnification. As described with reference to FIG. 7A, when taking a picture at the wide-angle end, the zoom lenses 3a, 3b, 3c are housed. There is little inclination. Therefore, it is possible to use an image A ₀ captured by the wide-angle end around shift image without the angle of view.

  Next, in step S34, the camera control unit 36 gives a signal to the zoom control unit 26, drives the zoom drive unit 28, changes the zoom magnification of the zoom lens unit 3 to the telephoto end side by a predetermined amount, and zoom lens Change the feeding distance of unit 3. In this process, the extension distance of each zoom lens 3a, 3b, 3c constituting the zoom lens unit 3 is increased by a distance corresponding to the changed zoom stage.

Next, in step S35, the camera control unit 36 newly captures and stores an image _An (not shown). In this process, since the zoom lens unit 3 extended to the telephoto end side by a predetermined amount is used for shooting, when correction by shift of the image sensor 7 is not performed, as described with reference to FIG. In addition, the captured image _An has a center shift of the angle of view.

Next, in step S36, the camera control unit 36 performs the process of determining the deviation between the images _{A n} captured by the image _{A 0} and the new step S35 captured at step 33. In this process, it detects the angle the center of the image A ₀ captured at Step S33, the center of the angle of view of the image A _n captured by the time the new zoom factor at step S35. Then, the center of the angle of view of the image A ₀ captured in step S33, difference in position between the angle of view center of the image A _n captured by the new zoom magnification in step S35, for example, has been described with reference to FIG. 7 The difference between the points C ₁ and C ₂ on the image sensor is determined as the amount of deviation.

Next, in step S <b> 37, the camera control unit 36 stores the displacement amount of the image sensor corresponding to the determined image displacement amount as the optical axis correction amount corresponding to the current zoom magnification. In this process, the center of the angle of view of the image A ₀ of the last, a shift amount obtained from the difference in position between the center of the angle of view of the image A _n captured at a new zoom factor, according to the current zoom magnification The correction amount is stored in the related data storage unit 23.

  Next, in step S38, the camera control unit 36 performs a process of determining whether or not the current zoom magnification is at the telephoto end. If the camera control unit 36 determines that the zoom magnification is at the telephoto end, the process proceeds to step S39. If the camera control unit 36 determines that the zoom magnification is not at the telephoto end, the process returns to step S34. That is, in this process, by repeating the processes of steps S34 to S38, the zoom magnification is changed by a predetermined amount, and an image is captured a plurality of times for each zoom magnification from the wide-angle end to the telephoto end. Thus, the shift amount for each zoom magnification can be detected and stored in the relational data storage unit 23 as a correction amount for each zoom magnification. Therefore, the relation data is determined based on the image shift amount obtained for each zoom magnification, and the center of the field angle of the captured image is determined based on the correction amount corresponding to each zoom magnification in the determined relation data. Misalignment can be corrected. Therefore, the angle-of-view center shift can be reduced based on the relational data indicating a plurality of shift amounts obtained for each zoom magnification, and therefore, shooting with less center-of-view angle shift based on a highly accurate correction amount. Images can be acquired. Furthermore, since the relevant data is automatically set when the power is turned on without any particular attention to the deviation correction, the optimum relation data can always be set, so that the optical axis deviation correction is performed with high accuracy. In addition, it is possible to reduce the burden on the user with respect to optical axis misalignment correction.

  Next, in step S39, the camera control unit 36 returns the zoom magnification to the specified position and shifts to the shooting standby state. When this process is performed, the calibration process is terminated.

<Explanation of shooting examples>
With reference to FIG. 6, an example of photographing a landscape image in a state where the subject 101 is contained within the angle of view 100 by the digital camera 1 provided with the angle-of-view center deviation correcting device 5 according to the present embodiment is shown.

FIG. 6A shows an example of shooting when the subject 101 is shot at the wide-angle end with a low zoom magnification. FIG. _6A shows a state where the optical axis 41 of the digital camera 1 is directed to the center PC _{a1 of the} angle of view 100 including the subject 101. When the shutter key 17 is pressed in this state, the shutter is opened and the subject 101 is turned on. Is imaged around a point C _a1 where the optical axis 41 hits in the image sensor 7. As a result, a captured image centered on the point C _a1 corresponding to the center PC _{a1 of the} angle of view 100 is acquired. When the zoom magnification is low, it is difficult for the center of the angle of view to be shifted in the captured image. Therefore, even when the shift correction is not performed, it is possible to acquire a moving image with a small center shift of the angle of view.

  FIG. 6B shows a shooting example when the subject 101 is shot on the telephoto end side with a high zoom magnification. When the zoom magnification is high, the zoom lens unit 3 is inclined due to the weight of each of the zoom lenses 3a, 3b, 3c constituting the zoom lens unit 3, factors due to the lens mechanism, and the like, and the center deviation of the angle of view is likely to occur. For this reason, when the center deviation of the angle of view is left unattended, it becomes difficult to generate an image in which the center of the angle of view is not displaced as described with reference to FIG. Therefore, in the present embodiment, when the zoom magnification is increased, the image sensor correction stage is referred to based on the correction amount corresponding to the current zoom magnification with reference to the relationship data stored in the relationship data storage unit 23. Shift 8 Thus, correction by the zoom correction operation is performed so that the center of the angle of view of the subject 101 forms an image at the center position of the angle of view of the image sensor 7.

As shown in FIG. 6B, when the image sensor correction stage 8 is shifted according to the zoom magnification, imaging is performed so that the optical axis 41 of the digital camera 1 faces the center PC _{a1 of the} angle of view 100 including the subject 101. The element 7 is corrected. When the shutter key 17 is pressed in this state, the shutter is opened, and the subject image is formed with the position where the optical axis 41 hits the image sensor 7 as the field angle center position, and the point C corresponding to the center PC _a1 of the field angle 100 A captured image centered on _a1 can be acquired.

  Specifically, it is fixed by the image sensor correction stage 8 according to each correction amount corresponding to the current zoom magnification of the relation data detected by the deviation amount detection section 22 and stored in the relation data storage section 23. By moving the connected image sensor 7 in a direction that cancels the misalignment of the view angle center, and correcting the misalignment of the view angle center of the photographed image captured by the image sensor 7, the image of the photographed image captured by the image sensor 7 is corrected. By correcting the misalignment of the corner center, it is possible to acquire a captured image with a small misalignment of the view angle center even during the zoom operation.

As described above, the shift amount in the captured image acquired by the image sensor 7 at each zoom magnification is stored in the relational data storage unit 23 as the correction amount. Then, based on the correction amount corresponding to each zoom magnification in the stored relational data, the image sensor 7 fixedly connected by the image sensor correction stage 8 is moved in a direction to cancel the center deviation of the angle of view. Thus, it is possible to correct the misalignment of the center of the angle of view of the captured image taken by the above method. Thereby, the field angle center shift can be reduced based on the relational data indicating the correction amount corresponding to each zoom magnification stored in advance. Therefore, at the time of shooting, the angle of view is calculated based on the highly accurate shift amount. A photographed image with little center shift can be acquired.
In particular, when performing fixed-point observations on a distant subject with the camera fixed on a tripod, the shooting position will not shift even if the zoom magnification is changed by remote control, etc. It is possible to observe freely from the subject to the subject up as needed.

  Although one embodiment of the present invention has been described above, the present invention is not limited to this, and various modifications other than those described above can be made without departing from the spirit of the present invention.

  For example, when the power switch is operated by the user and the power is turned on, the camera control unit 36 sets the automatic determination mode, executes the calibration process, and the related data stored in the related data storage unit 23 Is automatically determined, but is not limited to this. For example, the related data may be switched manually by a user operation without automatically determining the related data even when the power is turned on. Also, the calibration process is executed only when the camera can be fixed using a tripod or the like. If there is no instrument for fixing the camera such as a tripod, the calibration process is not executed. Data may be used.

Although the zoom correction operation and the camera shake correction operation can be switched by setting the camera shake correction mode or the monitoring mode, the present invention is not limited to this. For example, it may be switched by the operation of the operation unit 35 by the user according to the surrounding shooting conditions.
In the above embodiment, zoom correction processing is performed when the camera shake correction mode is not set, the monitoring mode is set, and the video shooting or continuous shooting is performed (when all the conditions are satisfied). However, zoom correction processing may be executed when one or two conditions are satisfied instead of all of these conditions. Further, the photographer may arbitrarily set a combination of conditions for executing the zoom correction process according to the situation.

DESCRIPTION OF SYMBOLS 1 Digital camera 2 Imaging system 3 Zoom lens unit 3a, 3b, 3c Zoom lens 4 Focus lens 5 Angle-of-view center deviation correction device 7 Imaging element 8 Imaging element correction stage 22 Deviation amount detection part 23 Relation data storage part 24 Blur detection part 25 Image sensor control unit 26 Zoom control unit 27 Image sensor drive unit 28 Zoom drive unit 29 Timing generation unit 30 Signal processing unit 31 Image processing unit 32 Display processing unit 33 Display monitor 34 Recording unit 35 Operation unit 36 Camera control unit 41 Optical axis 100 Angle of view 101 Subject

Claims (11)

A retractable zoom lens unit including a plurality of zoom lenses arranged along the optical axis;
Imaging means for continuously capturing images with an image sensor via the plurality of zoom lenses;
Zoom magnification setting means for setting the zoom magnification;
Zoom means for moving each zoom lens based on the zoom magnification set by the zoom magnification setting means;
A blur detection unit for detecting a blur amount generated in the imaging unit;
An optical axis correction unit that corrects a deviation of the optical axis by moving the imaging element in a predetermined direction, and
The optical axis correcting means is
A zoom correction operation for correcting a deviation of the optical axis in accordance with the zoom magnification set by the zoom magnification setting means;
And a camera shake correction operation for selectively correcting a shake of a subject image picked up by the image pickup device in accordance with a shake amount detected by the shake detection means.   A correction mode in which the optical axis correction unit corrects an optical axis shift, a zoom correction mode in which the optical axis correction unit performs the zoom correction operation according to a shooting situation, and an optical axis correction unit in which the camera shake correction is performed. The angle-of-view-center shift correction device according to claim 1, further comprising correction mode setting means for setting to any one of a camera shake correction mode for performing an operation.   The optical axis correction unit performs only the camera shake correction operation without performing the zoom correction operation when the camera shake correction mode is set by the correction mode setting unit. Item 3. A field angle center misalignment correction apparatus according to Item 2. Comprising a monitoring mode setting means for setting a monitoring mode for photographing while changing the zoom magnification of the zoom magnification setting means by remote control with the digital camera fixed;
3. The optical axis correction unit performs only the zoom correction operation without performing the camera shake correction operation when the monitoring mode is set by the monitoring mode setting unit. The field angle center misalignment correction apparatus described. Relation data storage means for storing relation data indicating the relation between the zoom magnification set by the zoom magnification setting means and the correction amount according to the zoom magnification;
The correction amount determination means for determining a correction amount when the optical axis correction means performs the zoom correction operation based on the relation data stored in the relation data storage means. 1. A field angle center misalignment correction apparatus according to 1.   6. The angle of view according to claim 5, further comprising changing means for manually or automatically changing the relation data indicating a relation between the zoom magnification stored in the relation data storage means and the correction amount. Center misalignment correction device. A determination mode setting means for setting an automatic determination mode for determining the relation data;
When the automatic determination mode is set by the determination mode setting means, the image pickup device takes an image through the plurality of zoom lenses by the image pickup means while changing the zoom magnification set by the zoom magnification setting means. A deviation amount detecting means for detecting a deviation amount of the image taken by the imaging means for each zoom magnification by image analysis;
And a relational data determining unit that determines the relational data indicating the relationship with the correction amount according to the zoom magnification based on the deviation amount detected by the deviation amount detecting unit. Item 6. The field angle center misalignment correction apparatus according to Item 5.   2. The angle-of-view-center shift correction device according to claim 1, wherein the optical axis correction unit determines a moving speed of the image sensor according to a speed at which the imaging unit continuously captures images.   6. The angle-of-view-center shift correction device according to claim 5, further comprising a power-on setting unit that automatically sets the relational data stored in the relational data storage unit when the power is turned on.   The digital camera according to claim 1, comprising the angle-of-view center deviation correcting device. A shift correction method for correcting a shift of an optical axis by a field angle center shift correction device having a retractable zoom lens unit including a plurality of zoom lenses arranged along an optical axis,
The displacement correction method includes an imaging step of continuously capturing images with an image sensor through the plurality of zoom lenses;
A zoom magnification setting step for setting the zoom magnification;
A zoom step of moving each zoom lens based on the zoom magnification set in the zoom magnification setting step;
A blur detection step for detecting a blur amount generated between the plurality of zoom lenses and the image sensor;
An optical axis correction step of correcting the shift of the optical axis by moving the image sensor in a predetermined direction, and
The optical axis correction step includes
A zoom correction operation for correcting a shift of the optical axis in accordance with the zoom magnification set in the zoom magnification setting step;
And a camera shake correction operation for selectively correcting the camera shake of a subject image picked up by the image sensor in accordance with the amount of camera shake detected in the camera shake detection step.

Images