JP5541661B2 - LENS DEVICE, IMAGING SYSTEM, AND CONTROL METHOD THEREOF - Google Patents

Description

  The present invention relates to an imaging system and a lens apparatus that perform focus adjustment based on a focus state of a photographing optical system and focus adjustment (focus shake correction) based on a detection result of shake in an optical axis direction.

  Camera or lens shake due to camera shake or the like includes so-called angular shake, which is shake in the rotational direction such as the pitch direction and yaw direction, and the angular shake can be detected by an angular velocity sensor such as a gyro sensor. The output from the angular velocity sensor is converted into angular displacement by integral calculation, and the image blur due to angular shake is corrected (reduced) by shifting the correction lens in a plane orthogonal to the optical axis in accordance with the angular displacement. Can do.

  In general, when the photographing magnification is 0.1 times or less, a stable image with less shake can be obtained by correcting the image shake with respect to the angular shake described above. However, when the photographing magnification is larger than 0.1 times, a so-called parallel shake that is a shake in a direction orthogonal to the optical axis is also a problem, and when the photographing magnification is further increased, a shake in the optical axis direction (focus direction) is caused. Some so-called focus fluctuations cannot be ignored. This is because the parallel shake occurs as a shift of the image position on the image plane proportional to the shooting magnification, and the focus shake occurs as a focus variation proportional to the square of the shooting magnification.

  In Patent Documents 1 and 2, a parallel shake and a focus shake are detected by using an acceleration sensor, and the correction lens is shifted in a plane orthogonal to the optical axis, or the focus lens is moved in the optical axis direction. In addition, a technique for correcting focus shake is disclosed.

JP 07-225405 A JP 2006-091279 A

  The focus shake correction described above is one of focus adjustment functions using an acceleration sensor. However, Patent Documents 1 and 2 describe AF functions of many cameras, that is, a function of moving a focus lens based on a focus state of a photographing optical system detected by a phase difference detection method or a contrast detection method, and focus shake correction. It does not mention the relationship with functions.

  In addition, the AF of the camera has a servo AF function that repeats AF processing so as to follow the movement of the subject. However, if the servo AF function is used when the shooting magnification is high, the subject is likely to come off from the shooting screen due to camera shake such as camera shake, so the subject tracking of servo AF is not performed well, and a large blur may occur.

  The present invention provides an imaging system and a lens apparatus that can perform an appropriate focus adjustment operation in accordance with a photographing magnification.

An imaging system according to an aspect of the present invention is an imaging system that captures a subject image formed by a photographic optical system including a focus lens, and includes a focus detection unit that detects a focus state of the photographic optical system, and an optical axis. A shake detection unit that detects a shake of the imaging system in a direction, a magnification calculation unit that calculates a shooting magnification obtained by the shooting optical system, and a focus detection unit that detects when the shooting magnification is smaller than a predetermined value. Focus adjustment is performed by moving the focus lens based on the focus state, and when the photographing magnification is larger than the predetermined value, the focus lens is moved based on the shake detected by the shake detection unit. A focus adjustment unit that performs focus adjustment at the time when the photographing magnification is greater than the predetermined value. In response to the fact that the focus adjustment for moving the focus lens based on the shake detected by the shake detection means is repeated a predetermined number of times or for a predetermined time before the start of the captured image acquisition operation in the above, the focus detection means The focus adjustment is performed based on the focus state detected by .

A lens device according to another aspect of the present invention is a lens device that includes a photographing optical system including a focus lens and is detachably attached to the imaging device, and the lens device in the optical axis direction. A shake detecting means for detecting a shake of the camera, a magnification calculating means for calculating a photographing magnification obtained by the photographing optical system, and the focus based on a focus state of the photographing optical system when the photographing magnification is smaller than a predetermined value. Focus adjustment unit that performs focus adjustment by moving a lens, and performs focus adjustment by moving the focus lens based on the shake detected by the shake detection unit when the photographing magnification is larger than the predetermined value. And the focus adjusting unit is configured to adjust the amplitude before starting the captured image acquisition operation when the imaging magnification is greater than the predetermined value. The focus adjustment is performed based on the focus state of the photographing optical system in response to the focus adjustment for moving the focus lens based on the shake detected by the detection unit being repeated a predetermined number of times or for a predetermined time. And

  According to the present invention, when the photographing magnification is small, the focus adjustment is performed based on the focus state of the photographing optical system, so that a good in-focus state that cannot be obtained by the focus adjustment based on the focus shake can be obtained. On the other hand, when the shooting magnification is large, focus adjustment (focus shake correction) is performed based on the focus shake, which improves blurring caused by camera shake such as camera shake that is difficult to handle with focus adjustment based on the focus state of the shooting optical system. It can be avoided. Thus, an appropriate focus adjustment operation can be performed according to the photographing magnification.

1 is a schematic diagram showing a configuration of a lens interchangeable digital single-lens reflex camera system that is an embodiment of the present invention. The block diagram which shows the electric constitution of the said camera system. 7 is a flowchart showing a servo AF operation in the camera system. 7 is a flowchart showing a focus shake correction operation in the camera system. The flowchart which shows the operation | movement during the image acquisition in the said camera system.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a schematic configuration of a lens interchangeable digital single-lens reflex camera system (imaging system) that is an embodiment of the present invention.

  In FIG. 1, reference numeral 1 denotes a camera body as an imaging apparatus, and reference numeral 2 denotes an interchangeable lens as a lens apparatus that is detachably attached to the camera body 1.

  In the camera body 1, 3 is a main mirror. In the viewfinder observation state, the main mirror 3 is disposed at a down position on the optical path of the light beam from the photographing lens (photographing optical system) in the interchangeable lens 2, guides a part of the light beam to the optical viewfinder, and the other part. Is guided to the focus detection unit 5 through the sub mirror 4. The optical viewfinder includes a pentaprism 7 and an eyepiece lens 8. The main mirror 3 is retracted from the optical path to the up position during an imaging operation (exposure operation).

  The focus detection unit 5 includes a condenser lens that splits an incident light beam into two light beams, two separator lenses that re-image the two split light beams, and a CCD that photoelectrically converts the two imaged subject images. Line sensor (AF sensor). The focus detection unit 5 detects the phase difference between the two subject images in order to perform so-called phase difference detection AF. The line sensors are arranged in a cross shape so as to detect subject images in the vertical direction (Y-axis direction) and the horizontal direction (X-axis direction).

  Reference numeral 6 denotes an image pickup element as a photoelectric conversion element such as a CMOS sensor or a CCD sensor that photoelectrically converts a subject image formed by the photographing lens.

  In the interchangeable lens 2, 11 is a first lens unit, 12 is a second lens unit as a focus lens, and 13 is a third lens unit as a variable power lens. Reference numeral 14 denotes a fourth lens unit as a correction lens for shift shake and parallel shake. Reference numeral 15 denotes a diaphragm 15 for adjusting the amount of light. The first to fourth lens units 11 to 14 and the diaphragm 15 constitute a photographing lens (photographing optical system).

  The second lens unit 12 receives the driving force from the AF motor 16 and moves in the direction along the optical axis AXL (hereinafter referred to as the optical axis direction) to perform focus adjustment. The amount of movement for adjusting the focus of the second lens unit 12 is determined according to the defocus amount of the photographing lens calculated based on the phase difference detected by the focus detection unit 5.

  The second lens unit 12 is moved in the optical axis direction in response to a driving force from the AF motor 16 in order to reduce (correct) focus fluctuation due to shake in the optical axis direction of the camera system. Thereby, focus shake correction for reducing (correcting) focus shake is performed. The movement amount for correcting the focus shake of the second lens unit 12 is calculated based on the output from the acceleration sensor 18 according to the shake acceleration in the optical axis direction. The focus shake correction is a kind of focus adjustment.

  The third lens unit 13 converts the rotational force of a zoom operation ring (not shown) operated by the photographer into a driving force in the optical axis direction and transmits the driving force to the third lens unit 13 in the optical axis direction. Move and scale.

  The fourth lens unit 14 receives a driving force from the anti-vibration actuator 19 and shifts in a plane orthogonal to the optical axis AXL (hereinafter, optical axis orthogonal plane). The shift amount at this time is calculated based on the output from the angular velocity sensor 17 such as a vibration gyro. As a result, angle blur correction for reducing (correcting) image blur due to angular blur is performed. The fourth lens unit 14 shifts in the optical axis orthogonal plane by the shift amount calculated based on the output from the acceleration sensor 18 according to the shake acceleration in the optical axis orthogonal direction. Thereby, parallel shake correction for reducing (correcting) image blur due to parallel shake is performed. Actually, the fourth lens unit 14 shifts in the plane orthogonal to the optical axis by a shift amount corresponding to the combined displacement amount of the angular shake correction and the parallel shake.

  The anti-vibration actuator 19 includes a coil and a magnet. One of the coil and the magnet is attached to the fourth lens unit 14, and the other is attached to a base member (not shown) that supports the fourth lens unit 14 so as to be shiftable. ing. By energizing the coil, a thrust is generated between the coil and the magnet, and the fourth lens unit 14 is shifted by the thrust.

  The acceleration sensor 18 can detect acceleration in three directions, ie, the X-axis direction, the Y-axis direction, and the Z-axis direction (optical axis direction). Further, the angular velocity sensor 17 and the acceleration sensor 18 are arranged on a plane that is orthogonal to the optical axis AXL of the photographing optical system and includes the principal point P of the photographing optical system. Thereby, both the angular velocity sensor 17 and the acceleration sensor 18 can detect the angular velocity and acceleration of the shake at the position corresponding to the principal point P.

  The drive control of the vibration isolation actuator 19 is performed by a lens CPU described later. Further, the fourth lens unit 14 may move in a direction orthogonal to the optical axis by rotating around one point on the optical axis AXL, or may be a so-called variable apex angle prism.

  FIG. 2 shows an electrical configuration of the camera system of the present embodiment. Reference numeral 100 denotes a camera body, and reference numeral 200 denotes an interchangeable lens.

  Reference numeral 101 denotes a camera CPU constituted by a microcomputer. The camera CPU 101 controls the operation of each unit in the camera body 100. The camera CPU 101 communicates with the lens CPU 201 provided in the interchangeable lens 200 via the contacts 102 and 202 when the interchangeable lens 200 is mounted. Information (signals) transmitted from the camera CPU 101 to the lens CPU 201 includes focus lens drive amount information, parallel shake information, and focus shake information. The information (signal) transmitted from the lens CPU 201 to the camera CPU 101 includes imaging magnification information.

  A power switch 103 that can be operated by the photographer is a switch for starting up the camera CPU 101 and starting power supply to each actuator, sensor, and the like in the camera system.

  Reference numeral 104 denotes a release switch that can be operated by a photographer, and includes a first stroke switch SW1 and a second stroke switch SW2. A signal from the release switch 104 is input to the camera CPU 101. The camera CPU 101 enters a shooting preparation state in response to the input of the ON signal from the first stroke switch SW1. In the shooting preparation state, the measurement of the subject brightness by the photometry unit 105 and the focus detection by the phase difference detection method by the focus detection unit (focus detection means) 106 including the focus detection unit 5 shown in FIG.

  The camera CPU 101 calculates the aperture value of the aperture unit 15, the exposure amount of the image sensor 6 (in the shutter speed), and the like based on the photometric result. The camera CPU 101 also obtains a focus state with respect to the subject based on focus information (defocus amount and defocus direction) that is a detection result of the focus state of the photographing optical system by the focus detection unit 106. 2 driving amount (including the driving direction) is determined. The information on the driving amount (focus lens driving amount information) is transmitted to the lens CPU 201. The lens CPU 201 controls the operation of each component in the lens 2.

  Furthermore, when the camera CPU 101 receives an ON signal from the image stabilization operation switch 203 provided in the interchangeable lens 200, the camera CPU 101 starts shift control of the fourth lens unit 14.

  In this embodiment, when the photographing magnification is larger than a predetermined value, the parallel shake detection unit 108 provided in the camera body 100 shakes the subject image formed on the AF sensor in the X-axis direction and the Y-axis direction. Detects parallel shake. Then, the detection result is transmitted to the lens CPU 201 as parallel shake information in the X-axis direction and the Y-axis direction.

  Further, the focus shake detection unit 107 provided in the camera body 100 detects a shake in the focus direction (Z-axis direction), that is, a focus shake displacement amount (including the direction) based on a change in focus information, and this is detected. This is transmitted to the lens CPU 201 as shake information.

  When an ON signal is input from the second stroke switch (SW2), the camera CPU 101 transmits an aperture drive command to the lens CPU 201, and causes the aperture unit 15 to set the previously calculated aperture value. In addition, the camera CPU 101 transmits an exposure start command to the exposure unit 109 to perform a retracting (up) operation of the mirrors 3 and 4 and an opening operation of a shutter (not shown), and in the imaging unit 110 including the imaging device 6, The subject image is photoelectrically converted, that is, an exposure operation is performed.

  An image pickup signal from the image pickup unit 110 (image pickup element 6) is converted into a digital signal by the signal processing unit 111, further subjected to various correction processes, and output as an image signal. The image signal (data) is recorded and stored in a recording medium such as a semiconductor memory such as a flash memory, a magnetic disk, and an optical disk in the image recording unit 112.

  The lens contact 202 includes a signal transmission contact for exchanging signals with the camera 1 side, and a power contact for receiving power supply from the camera 1 side.

  An image stabilization operation (IS) switch 203 is operated by a photographer to select whether to perform image blur correction control. The ON signal from the IS switch 203 is also transmitted to the camera 1 side via the lens CPU 201.

  Reference numeral 204 denotes an angular velocity sensor corresponding to the angular velocity sensor 17 shown in FIG. The angular velocity sensor 204 includes a detection unit that outputs angular velocity signals indicating the angular velocities of vertical (pitch direction) shake and lateral (yaw direction) shake, which are angular shakes of the camera system. Further, the angular velocity sensor 204 includes an arithmetic output unit that outputs a displacement signal indicating displacement (angular shake displacement amount) of pitch direction shake and yaw direction shake obtained by integrating the angular velocity signal from the detection unit to the lens CPU 201. Have. The angular velocity sensor 204 is controlled to be turned on / off by a command signal from the lens CPU 201.

  Reference numeral 205 denotes an acceleration sensor (vibration detecting means) corresponding to the acceleration sensor 18 shown in FIG. The acceleration sensor 18 detects acceleration in three directions, ie, an X-axis direction, a Y-axis direction, and a Z-axis direction, which are orthogonal to each other, using an inertial force generated by vibration, and indicates the acceleration. A signal is output to the lens CPU 201.

  Reference numeral 206 denotes an acceleration / speed calculation unit. The acceleration / velocity calculation unit 206 converts the parallel shake information in the X-axis and Y-axis directions and the focus shake information in the Z-axis direction, which are input from the camera body 100, respectively, into the shooting magnification of the shooting optical system (this will be described later). According to the above, it is converted into a parallel shake displacement amount and a focus shake displacement amount. The acceleration / speed calculation unit 206 calculates the parallel shake speed and parallel shake acceleration in the X-axis and Y-axis directions, and the focus shake speed and focus shake acceleration in the Z-axis direction from the parallel shake displacement amount and the focus shake displacement amount. To do.

  If the angular shake correction has already been performed, the shake in the X-axis direction and the Y-axis direction can be regarded as only the parallel shake component from which the angular shake component has been removed.

  Reference numeral 207 denotes a correction value calculation unit. The correction value calculation unit 207 calculates the difference between the parallel and focus shake acceleration calculated by the acceleration / speed calculation unit 206 and the acceleration (hereinafter referred to as sensor detection acceleration) indicated by the signal from the acceleration sensor 205. Then, the difference is used as a correction value for the sensor detected acceleration. This correction value is calculated for each of the X-axis, Y-axis, and Z-axis directions, and stored in the correction value calculation unit 207 as an acceleration correction value for each direction. This correction value corresponds to gravitational acceleration. The correction value calculation in the correction value calculation unit 207 is repeated until the start of the exposure operation in the camera body 100, and the acceleration correction value is updated and stored as needed.

  Reference numeral 208 denotes a deflection displacement calculation unit. The shake displacement computing unit 208 removes the gravitational acceleration component from the sensor detected acceleration by adding correction based on the acceleration correction value calculated by the correction value computing unit 207 to the sensor detected acceleration. Thereafter, the shake displacement calculation unit 208 calculates the shake speed by integrating the corrected acceleration, and further integrates the shake to calculate the parallel shake excluding the gravitational acceleration component based on the detection result of the acceleration sensor 205. The displacement amount is calculated.

  Note that in the calculation of the shake speed and shake displacement, it is necessary to obtain the initial shake speed of the camera system, so the shake speed (parallel, focus shake speed) obtained by the acceleration / speed calculator 206 is set as the initial speed. To do.

  Reference numeral 209 denotes a shake synthesis unit. The shake synthesizing unit 209 uses the parallel shake displacement amount based on the acceleration sensor output calculated by the shake displacement calculating unit 208 and the angular shake displacement amount (pitch and yaw direction) obtained from the detection result by the angular velocity sensor 204. The shift amount (shake correction amount) of the fourth lens unit 14 is determined. Specifically, the shake displacement amount due to the parallel shake in the X-axis direction and the shake displacement amount due to the angular shake in the yaw direction are combined, and the shake displacement amount due to the parallel shake in the Y direction and the shake displacement due to the angular shake in the pitch direction are combined. Synthesize the quantity. Then, the shift amount (including the shift direction) of the fourth lens unit 14 is determined from the combined shake displacement amount.

  Reference numeral 210 denotes a focus shake correction amount calculation unit. The focus shake correction amount calculation unit 210 calculates a drive amount (and direction) for focus shake correction of the second lens unit 12 based on the focus shake displacement amount.

  Reference numeral 211 denotes a correction drive control unit. In response to turning on the IS switch 203, the correction drive control unit 211 selectively executes shake correction control based on angular shake or shake correction control based on a total value (combined value) of angular shake and parallel shake. Specifically, the correction drive control unit 211 has a predetermined value (for example, 0.2 to 0.3 times, more preferably 0.1 times) as the imaging magnification obtained from the lens focal length information and the focus lens position information. In the case of smaller normal shooting, shake correction control based on only angular shake is performed. In addition, in the case of macro photography in which the imaging magnification is larger than the predetermined value, shake correction control based on only the angular shake is performed before the start of exposure, and after the start of exposure, the shake based on the total amount of the angular shake and the parallel shake is performed. Perform correction control.

  The acceleration / speed calculation unit 206 to the correction drive control unit 211 are provided in the lens CPU 201. The camera CPU 101 and the lens CPU 201 constitute a focus adjustment unit.

  A correction drive unit 212 includes the image stabilization (IS) actuator 19 shown in FIG. 1 and its drive circuit. The IS actuator 19 includes an X-direction actuator configured by a permanent magnet and a coil that drives the fourth lens unit 14 in the X-axis direction, and a permanent magnet and a coil that drives the fourth lens unit 14 in the Y-direction. And a configured Y-direction actuator.

  In the interchangeable lens 200, a lock mechanism is provided for holding the fourth lens unit 14 at a position where its optical axis coincides with the optical axis AXL of the photographing optical system.

  In response to a command signal from the lens CPU 201, the correction driving unit 212 locks the locking mechanism when the IS switch 203 is turned off (when shake correction is stopped), and when the IS switch 203 is turned on (shake). The lock mechanism is unlocked during the correction operation.

  Reference numeral 213 denotes a focusing drive unit. The in-focus driving unit 213 drives the AF motor 16 according to information on the driving amount (and driving direction) of the second lens unit 12 transmitted from the camera CPU 101 to perform autofocus driving of the second lens unit 12. Further, the focus drive unit 213 responds to the information on the drive amount (and direction) for focus shake correction from the focus shake correction amount calculation unit 210 when the shooting magnification is higher than the predetermined value at the time of shake correction. The AF motor 16 is driven. Thereby, focus shake correction driving of the second lens unit 12 is performed.

  Reference numeral 214 denotes an aperture driving unit. The aperture drive component 214 is controlled by the lens CPU 201 that has received an aperture drive command from the camera CPU 101, and operates the aperture unit 15 shown in FIG. 1 in an aperture state corresponding to the aperture value specified by the command.

  Reference numeral 215 denotes a photographing magnification detection unit (magnification calculation means). The photographing magnification detection unit 215 includes a first detection unit that detects the position of the variable power lens (third lens unit) 13 and a second detection unit that detects the position of the focus lens (second lens unit) 12. Furthermore, the photographing magnification detection unit 215 also includes a calculation unit that calculates the photographing magnification obtained by the photographing optical system based on the position information from the first and second detection units. Information on the photographing magnification calculated by the calculation unit is transmitted to the acceleration / speed calculation unit 206 and also to the camera CPU 101 via the lens CPU 201.

  Next, the operation of the camera system shown in FIG. 2 will be described using the flowcharts of FIGS. 3, 4, and 5. This operation is executed according to computer programs stored in the camera CPU 101 and the lens CPU 201.

  First, FIG. 3 shows a flowchart of basic operations of the camera system. When the power switch 103 is turned on, power supply to the camera body 100 and the interchangeable lens 200 is started, and communication between the camera CPU 101 and the lens CPU 201 is also started.

  In step (hereinafter referred to as “S”) 01, the camera CPU 101 determines whether or not the first stroke switch SW1 is turned on. If it is ON, the process proceeds to S02, and if it is not ON, S01 is repeated.

  In S02, the lens CPU 201 detects the state of an AF / MF switch (not shown) and determines whether AF is selected or manual focus (MF) is selected. If the manual focus is selected, the process proceeds to S03 and the manual focus is permitted. On the other hand, if AF is selected, the process proceeds to S04, and the lens CPU 201 determines whether or not the IS switch 203 is ON. If the IS switch 203 is ON, the process proceeds to S05. The process at S05 will be described later.

  On the other hand, if the IS switch 203 is not turned on, the lens CPU 201 detects the position A (that is, the focal length of the photographing optical system) A of the third lens unit 13 that is a variable power lens in S06, and sends it to the camera CPU 101. Send. In step S <b> 07, the camera CPU 101 calculates the defocus amount B of the photographing optical system through the focus detection unit 106.

  Further, in step S08, the camera CPU 101 determines whether or not the defocus amount B is a value within a predetermined focusing range, that is, whether or not it is in focus. If not in focus, the camera CPU 101 captures the position C of the second lens unit 12 that is the focus lens from the lens CPU 201 in S12.

  In S13, the camera CPU 101 calculates a focus lens drive amount (target position) for obtaining a focused state based on the focal length A, the focus lens position C, and the defocus amount B, and the focus lens drive amount. Is transmitted to the lens CPU 201.

  In step S14, the lens CPU 201 moves the focus lens to a target position corresponding to the focus lens driving amount. Thereby, AF (focus adjustment) based on the focus state detected by the focus detection unit 106 is performed. Thereafter, the camera CPU 101 calculates the defocus amount again in S07, and determines whether or not the camera is in focus in S08. If it is not in focus, S12 to S14 are repeated, and if it is in focus, the process proceeds to S09.

  In S09, the camera CPU 101 determines whether or not the second stroke switch SW2 is turned on. If not, the camera CPU 101 returns to S07 and repeats the processes of S07 and S08 (the processes of S12 to S14 if the focus state is not reached). . Thus, in the present embodiment, the servo AF that repeats the AF operation is performed from when the first stroke switch SW1 is turned on until the second stroke switch SW2 is turned on. If the second stroke switch SW2 is ON, the process proceeds to S10.

  In S10, the camera CPU 101 performs a captured image acquisition operation including the exposure operation described above. In step S11, the camera CPU 101 records a captured image. Thus, a series of operations is completed.

  Next, the process performed in S05 when the ON state of the IS switch 203 is determined in S04 will be described using the flowchart of FIG.

  In S <b> 21, the lens CPU 201 calculates the photographing magnification from the current position of the third lens unit 13 and the position of the second lens unit 12. Information on the shooting magnification is transmitted to the camera CPU 101. In S22, the lens CPU 201 resets the counter. The counter counts the number of times a loop from S29 to S35 described later is repeated.

  In S <b> 23, the camera CPU 101 determines whether the photographing magnification transmitted from the lens CPU 201 is smaller than a predetermined value M. When the shooting magnification is normal shooting smaller than the predetermined value M, the camera CPU 101 calculates the defocus amount E of the shooting optical system through the focus detection unit 106 in S24. In S25, the camera CPU 101 determines whether or not the defocus amount E is a value within a predetermined focusing range, that is, whether or not it is in a focused state. If not in focus, the camera CPU 101 captures the position C of the second lens unit 12 that is the focus lens from the lens CPU 201 in S26.

  In S27, the camera CPU 101 calculates a focus lens drive amount (target position) for obtaining a focused state based on the focal length A, the focus lens position C, and the defocus amount E, and the focus lens drive amount. Is transmitted to the lens CPU 201.

  In step S28, the lens CPU 201 moves the focus lens to a target position corresponding to the focus lens drive amount. Thereby, AF (focus adjustment) based on the focus state detected by the focus detection unit 106 is performed. Thereafter, the lens CPU 201 returns to S22, and repeats the processing of S22 to S28 until it is determined in S25 that it is in focus.

  If it is determined in S25 that the camera is in focus, the camera CPU 101 determines in S36 whether or not the second stroke switch SW2 has been turned on. If it is not ON, the process returns to S22 and repeats the processes of S22 to S25 (the process of S26 to S28 if the focus state is not reached). As described above, even when the IS switch 203 is turned on, the servo AF that repeats the AF operation is performed from when the first stroke switch SW1 is turned on until the second stroke switch SW2 is turned on. If the second stroke switch SW2 is ON, the process proceeds to S37.

  On the other hand, if it is determined in S23 that the shooting magnification is macro shooting greater than the predetermined value M, the lens CPU 201 calculates a focus shake displacement amount using a signal from the acceleration sensor 205 in S29. In step S30, the lens CPU 201 calculates a driving amount (target position) D of the second lens unit 12 based on the focus shake displacement amount, and further detects the position C of the second lens unit 12 in step S31. Thereafter, the lens CPU 201 increments the counter by one and proceeds to S33.

  In S <b> 33, the lens CPU 201 determines whether or not the detection position C of the second lens unit 12 matches the target position D. If they match, the process proceeds to S38 and waits for the second stroke switch SW2 to be turned on. If the detection position C of the second lens unit 12 does not coincide with the target position D, the lens CPU 201 moves the second lens unit 12 toward the target position D in S34. Thereby, focus shake correction (focus adjustment) based on a signal (focus shake) from the acceleration sensor 205 is performed. Then, the lens CPU 201 determines whether or not the value of the counter has reached a predetermined value F in S35.

  When the counter value reaches the predetermined value F, the camera CPU 101 performs the processes of S24 and S25. This performs AF using the focus detection unit 106 at a predetermined timing while performing focus shake correction based on a signal from the acceleration sensor 205, and corrects a shift in focus state caused by focus shake correction. Because.

  If the counter value does not reach the predetermined value F, the process returns to S23, and the imaging magnification is compared with the predetermined value M again. When the photographing magnification is larger than the predetermined value M, the process proceeds to S29 again, and the focus shake correction using the acceleration sensor 205 is continued. Further, when the distance from the camera to the subject changes during the focus shake correction and the photographing magnification becomes smaller than the predetermined value M, the process shifts to servo AF control using the focus detection unit 106.

  In S37, the camera CPU 101 performs a captured image acquisition operation including the exposure operation described above. In step S38, the camera CPU 101 records the captured image. Thus, a series of operations is completed.

  The flowchart of FIG. 5 shows focus shake correction control performed after the second stroke switch SW2 is turned on and the captured image acquisition operation is started. When the captured image acquisition operation is started, the lens CPU 201 calculates a focus shake displacement amount using a signal from the acceleration sensor 205 in S41. In step S42, the lens CPU 201 calculates a driving amount (target position) D of the second lens unit 12 based on the focus shake displacement amount. In step S43, the lens CPU 201 detects the position C of the second lens unit 12.

  Next, in S44, the lens CPU 201 determines whether or not the detection position C of the second lens unit 12 matches the target position D. If they match, the process proceeds to S46 and waits for the exposure operation time to end. If the detection position C of the second lens unit 12 does not coincide with the target position D, the lens CPU 201 moves the second lens unit 12 toward the target position D in S45. Thereby, focus shake correction (focus adjustment) based on a signal (focus shake) from the acceleration sensor 205 is performed. Thereafter, the process returns to S41, and the operation for focus shake correction is repeated.

  When the exposure operation time ends in S46, the lens CPU 201 ends this process.

  The embodiments described above are merely representative examples, and various modifications and changes can be made to the embodiments when the present invention is implemented.

  For example, in the above-described embodiment, the case where the parallel shake and the focus shake are detected using the output information from the AF sensor input from the camera body 100 has been described. However, the present invention is not limited to this, and for example, the image sensor 6 These may be detected using the output from.

  In this embodiment, the output from the AF sensor is used to calculate the correction value of the acceleration detected by the acceleration sensor 205 (exclusion of gravitational acceleration), and is further necessary to calculate the speed calculated based on the acceleration. The case where the initial speed is used has been described. However, the output from the AF sensor may be used for only one of these calculations.

  In the above embodiment, the case where the parallel shake correction and the focus shake correction are started simultaneously with the start of the exposure operation has been described. However, the parallel shake correction and the focus shake correction may be started before the exposure is started.

  Furthermore, in the above-described embodiment, the parallel shake detection unit 108 and the focus shake detection unit 107 are provided in the camera body 100, and the angular velocity sensor 204, the acceleration sensor 205, and the CPU that performs shake correction control are provided in the interchangeable lens 200. explained. However, each of these components may be provided in either the camera body or the interchangeable lens.

  For example, the angular velocity sensor and the acceleration sensor may be provided in the camera body together with the parallel shake detection unit and the focus shake detection unit, and the lens CPU may capture an output signal from these to perform shake correction control. Then, the parallel shake detection unit and the focus shake detection unit provided in the interchangeable lens may take in signals from the AF sensor of the camera body and perform the calculation of the parallel shake and the focus shake. Further, all calculations necessary for shake correction may be performed in the camera CPU, and a drive command (drive amount and direction command) for the fourth lens unit 14 may be transmitted to the interchangeable lens.

  Further, in the above-described embodiment, servo AF by the AF sensor is performed when the loop from S29 to S35 shown in FIG. 4 is repeated a predetermined number of times while performing focus shake correction based on information from the acceleration sensor. Explained the case. However, instead of repeating the loop from S29 to S35 a predetermined number of times, servo AF may be performed every predetermined time after the start of focus shake correction. Further, the servo AF is not necessarily performed during the focus shake correction.

  Furthermore, in the above-described embodiments, the interchangeable lens type digital single-lens reflex camera system has been described. However, the present invention can also be applied to a lens-integrated imaging system such as a digital still camera or a video camera in which lenses are integrally provided. it can.

  In the above-described embodiments, the case where the angular shake correction and the parallel shake correction are optically described has been described. However, the electronic protection that shifts the output region of the image signal acquired by the image sensor according to the shake is performed. You may carry out by a vibration process.

  It is possible to provide an imaging system and a lens apparatus that can perform an appropriate focus adjustment operation according to the imaging magnification.

DESCRIPTION OF SYMBOLS 1 Camera body 2 Interchangeable lens 5 Focus detection unit 6 Image pick-up element 12 2nd lens unit (focus lens)
13 Third lens unit (variable magnification lens)
14 Fourth lens unit (correction lens)
15 Aperture unit 16 AF motor 17, 204 Angular velocity sensor 18, 205 Acceleration sensor

Claims (4)

An imaging system for imaging a subject image formed by a photographing optical system including a focus lens,
Focus detection means for detecting a focus state of the photographing optical system;
Shake detecting means for detecting shake of the imaging system in the optical axis direction;
Magnification calculating means for calculating a photographing magnification obtained by the photographing optical system;
When the photographing magnification is smaller than a predetermined value, focus adjustment is performed by moving the focus lens based on the focus state detected by the focus detection unit, and when the photographing magnification is larger than the predetermined value, the shake is reduced. based on the shake the detected by the detecting means possess a focusing means for performing focus adjustment by moving the focus lens,
The focus adjustment unit performs a predetermined number of times of focus adjustment for moving the focus lens based on the shake detected by the shake detection unit before the start of a captured image acquisition operation when the shooting magnification is larger than the predetermined value. Alternatively, the focus adjustment is performed based on the focus state detected by the focus detection unit in response to being repeatedly performed for a predetermined time . A lens apparatus having a photographing optical system including a focus lens and detachably attached to an imaging apparatus,
Shake detecting means for detecting the shake of the lens device in the optical axis direction;
Magnification calculating means for calculating a photographing magnification obtained by the photographing optical system;
When the photographing magnification is smaller than a predetermined value, focus adjustment is performed by moving the focus lens based on a focus state of the photographing optical system, and when the photographing magnification is larger than the predetermined value, the shake detection unit based on the detected the shake possess a focusing means for performing focus adjustment by moving the focus lens,
The focus adjustment unit performs a predetermined number of times of focus adjustment for moving the focus lens based on the shake detected by the shake detection unit before the start of a captured image acquisition operation when the shooting magnification is larger than the predetermined value. Alternatively, the lens apparatus performs focus adjustment based on the focus state of the photographing optical system in response to being repeatedly performed for a predetermined time . A control method for an imaging system that captures a subject image formed by an imaging optical system including a focus lens,
A focus detection step of detecting a focus state of the photographing optical system;
A shake detection step of detecting shake of the imaging system in the optical axis direction;
A magnification calculating step for calculating a photographing magnification obtained by the photographing optical system;
When the photographing magnification is smaller than a predetermined value, focus adjustment is performed by moving the focus lens based on the focus state detected by the focus detection step. When the photographing magnification is larger than the predetermined value, the shake A focus adjustment step of performing focus adjustment by moving the focus lens based on the shake detected by the detection step,
In the focus adjustment step, the focus adjustment for moving the focus lens based on the shake detected by the shake detection step is started a predetermined number of times before the start of the captured image acquisition operation when the shooting magnification is larger than the predetermined value. Alternatively, the focus adjustment is performed based on the focus state detected by the focus detection step in response to being repeatedly performed for a predetermined time. A method for controlling a lens apparatus that has a photographing optical system including a focus lens and is detachably attached to an imaging apparatus,
A shake detection step for detecting a shake of the lens apparatus in the optical axis direction;
A magnification calculating step for calculating a photographing magnification obtained by the photographing optical system;
When the photographing magnification is smaller than a predetermined value, focus adjustment is performed by moving the focus lens based on a focus state of the photographing optical system. When the photographing magnification is larger than the predetermined value, the shake detection step A focus adjustment step of performing focus adjustment by moving the focus lens based on the detected shake, and
In the focus adjustment step, the focus adjustment for moving the focus lens based on the shake detected by the shake detection step is started a predetermined number of times before the start of the captured image acquisition operation when the shooting magnification is larger than the predetermined value. Alternatively, the lens apparatus control method includes performing focus adjustment based on a focus state of the photographing optical system in response to being repeatedly performed for a predetermined time.