JP2009145852A - Automatic focusing device, camera, automatic focusing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve highly accurate automatic focusing even if a camera shake occurs. <P>SOLUTION: An automatic focusing device includes: a photographing optical system 24 that has a focus lens; an outdoor light AF sensor 66 that measures the distance of a subject; a first focusing position acquiring section 102 that acquires a first focusing position of a focus lens corresponding to the measured distance of the outdoor light AF sensor 66; a second focusing position acquiring section 208 that acquires a second focusing position of the focus lens by detecting a focus based on an image formed on an image sensor 30; a camera shake quantity detecting section 68 that detects a quantity of camera shake; a weighing control section 120 that acquires a third focusing position by weighing the first and second focusing positions based on the quantity of camera shake detected by the camera shake quantity detecting section 68; and an AF control section 112 that moves the focus lens to the third focusing position. The third focusing position may be acquired by selecting the first or second focusing position based on the quantity of camera shake. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an autofocus device, a camera, and an autofocus method that perform a plurality of types of autofocus.

  In general, the auto-focus (hereinafter sometimes abbreviated as “AF”) of a photographing optical system is a distance measuring method such as a triangular distance measuring method or a propagation time detecting method, and a focus detecting method such as a contrast detecting method or a phase detecting method. being classified.

  In Patent Document 1, autofocus is performed by detecting the contrast between an external light AF (ranging method) that performs autofocus using a distance to a subject measured by an external light AF sensor and an image signal output from a CCD sensor. A configuration is disclosed in which the contrast detection AF that performs the above is selectively used according to the temperature detected by the temperature sensor.

Patent Document 2 discloses a configuration in which the shape of an autofocus block is changed when the occurrence of camera shake is detected in order to prevent autofocusing at a focal position not desired by the user.
JP-A-10-229516 JP 2003-107337 A

  In contrast detection AF, it is difficult to focus when camera shake occurs, and it is not possible to determine whether camera shake or subject shake does not match. Therefore, external light AF with less influence is desirable when the amount of camera shake is large.

  The configuration described in Patent Document 1 is useful in that an adverse effect on focusing accuracy due to temperature can be prevented, but the influence on focusing accuracy due to camera shake is not considered.

  The configuration described in Patent Document 2 does not support a case where a plurality of types of autofocus are performed.

  The present invention has been made in view of such circumstances, and an autofocus device, a camera, and an autofocus method capable of preventing adverse effects on focusing accuracy due to camera shake and realizing high-precision autofocus. The purpose is to provide.

  In order to achieve the above object, the invention according to claim 1 is directed to an imaging optical system having a focus lens, a distance measuring sensor for measuring a distance to a subject, and the focus corresponding to a measurement distance of the distance measuring sensor. Focus detection based on first focus position acquisition means for acquiring a first focus position of the lens, a light receiving element that receives light from the subject via the photographing optical system, and an output signal of the light receiving element Based on the camera shake amount detected by the camera shake amount detection means, the camera shake amount detection means for detecting the camera shake amount, and the second focus position acquisition means for acquiring the second focus position of the focus lens. And a focus position determining means for obtaining a third focus position by weighting the first focus position and the second focus position, and moving the focus lens to the third focus position. Focal Providing an autofocus apparatus characterized by comprising: a lens moving means.

  According to the present invention, the first in-focus position based on distance measurement and the second in-focus position based on focus detection are weighted based on the amount of camera shake, and the third in-focus position for actually moving the focus lens. Therefore, it is possible to prevent an adverse effect on focusing accuracy due to camera shake, and to realize high-precision autofocus.

  According to a second aspect of the present invention, in the first aspect of the present invention, the in-focus position determining means determines either the first in-focus position or the second in-focus position as the third in-focus position. An autofocus device is provided, wherein the third focus position is determined by selecting as a focus position.

  According to the present invention, high accuracy of autofocus can be realized with a simple configuration by selecting either the first focus position based on distance measurement or the second focus position based on focus detection. .

  According to a third aspect of the present invention, in the first aspect of the invention, the in-focus position determining unit is configured to detect the first in-focus position with respect to the amount of camera shake detected by the hand-shake amount detecting unit. And an autofocus device characterized in that the weight for the second in-focus position is continuously changed.

  According to the present invention, the weight for the first in-focus position based on the distance measurement and the weight for the second in-focus position based on the focus detection continuously change with respect to the amount of camera shake. It is possible to realize more accurate autofocus for a camera shake in a boundary region between a camera shake region with high reliability of the in-focus position and a camera shake region with high reliability of the second focus position. Further, when applied to continuous AF, even if the amount of camera shake changes in time series, the third in-focus position does not change sharply, so that the continuous autofocus operation is smooth.

  According to a fourth aspect of the present invention, in the first or third aspect of the present invention, the in-focus position determining means may be configured such that the greater the amount of camera shake, the first focusing corresponding to the measurement distance of the ranging sensor. An autofocus device characterized by increasing the weight of a focal position is provided.

  According to the present invention, the greater the amount of camera shake, the greater the weight of the first in-focus position, which is less susceptible to camera shake. Autofocus can be realized.

  According to a fifth aspect of the present invention, there is provided a photographing optical system having a focus lens, a distance measuring sensor for measuring a distance to a subject, and a first focus position of the focus lens corresponding to a measurement distance of the distance measuring sensor. First focus position acquisition means for acquiring the light, a light receiving element that receives light from the subject via the photographing optical system, and focus detection based on an output signal of the light receiving element to detect the first of the focus lens Based on the amount of camera shake detected by the amount of camera shake detected by the amount of camera shake detected by the amount of camera shake detected by the amount of camera shake detected by the second focus position acquiring means for acquiring the second focus position. On / off control means for switching on / off of the distance measuring operation, and when the distance measuring operation is in the on state, the position of the focus lens is determined using at least the first focus position. When the distance measuring operation is in the OFF state, the focus position determining means for determining the position of the focus lens using only the second focus position, and the position determined by the focus position determining means. There is provided an autofocus device comprising a focus lens moving means for moving the focus lens.

  According to the present invention, the distance measurement operation is switched on / off based on the amount of camera shake, and when the distance measurement operation is on, the position of the focus lens is determined using at least the first focus position. While suppressing the power consumption of the distance measuring sensor, it is possible to prevent an adverse effect on the focusing accuracy due to camera shake and to realize high-precision autofocus.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the on / off control unit is configured to focus the second focus position acquisition unit based on the amount of camera shake detected by the camera shake amount detection unit. ON / OFF of detection operation is switched, and the focus position determination means determines the position of the focus lens using only the first focus position when the focus detection operation is in an OFF state. An autofocus device is provided.

  According to the present invention, the power consumption of the focus detection operation can also be suppressed.

  The invention according to claim 7 is the invention according to any one of claims 1, 3, and 4, further comprising camera shake correction means for performing camera shake correction based on the amount of camera shake, and the in-focus position determination means. When the amount of camera shake exceeds a limit value or a limit value of camera shake correction by the camera shake correction unit, the first focus position and the second focus position are weighted and the third focus position is weighted. An autofocus device characterized by obtaining a focus position is provided.

  According to the present invention, the accuracy of autofocus is improved by camera shake correction, and the accuracy of autofocus is increased by weighting even under conditions where camera shake correction is not performed.

  The invention according to claim 8 is the invention according to claim 2, further comprising camera shake correction means for performing camera shake correction based on the camera shake amount, and the in-focus position determining means has the camera shake correction means for the camera shake correction means. An autofocus device is provided that selects the first in-focus position corresponding to the measurement distance of the distance measuring sensor when the limit value or the limit value of camera shake correction in (1) is exceeded.

  According to the present invention, the accuracy of autofocus is improved by camera shake correction, and the accuracy of autofocus is improved by selecting the first in-focus position even under conditions where camera shake correction is not performed.

  The invention according to claim 9 is the invention according to claim 5 or 6, further comprising camera shake correction means for performing camera shake correction based on the camera shake amount, and the on / off control means has the camera shake correction means for adjusting the camera shake amount. When the camera shake correction limit value or the threshold value indicating the limit value is exceeded, the distance measuring operation of the distance measuring sensor is set to the on state, and when the camera shake amount does not exceed the threshold value, the measurement is performed. Provided is an autofocus device characterized in that a distance measuring operation of a distance sensor is set to an off state.

  According to the present invention, the accuracy of autofocus is improved by camera shake correction, and the accuracy of autofocus can be increased using the first focus position even under conditions where camera shake correction is not performed. Power consumption due to the distance operation can be accurately suppressed.

  A tenth aspect of the invention is the invention of any one of the first, third, and fourth aspects, further comprising a camera shake correction unit that performs a camera shake correction based on the camera shake amount, and the camera shake correction unit includes: A correction limiting function for limiting camera shake correction to prevent overcorrection, and the in-focus position determining unit is configured to detect the camera shake amount detected by the camera shake amount detecting unit and the camera shake correcting unit during operation of the correction limiting function; The autofocus device is characterized in that the weight of the first in-focus position corresponding to the measurement distance of the distance measuring sensor is increased as the difference from the camera shake correction amount at is larger.

  According to the present invention, during the operation of the correction limiting function for preventing over-correction of camera shake, the greater the difference between the camera shake amount and the camera shake correction amount, the greater the weight of the first in-focus position by distance measurement. The influence of the camera shake is prevented, and the influence of the correction limiting function on the autofocus is covered.

  The invention according to claim 11 indicates that, in the invention according to any one of claims 1, 3, 4, 7, and 10, weighting is performed using the first in-focus position. Provided is an autofocus device including display means for performing the above-described operation.

  According to the present invention, since it is possible to notify the user whether or not autofocus using distance measurement is used, if the user determines that autofocus using distance measurement is acceptable, the user can shoot as it is. Thus, when auto-focus only by focus detection is desired, it is possible to take a picture after taking measures such as suppressing camera shake.

  A twelfth aspect of the invention is the display according to the second or eighth aspect of the invention, which displays which in-focus position is selected from the first in-focus position and the second in-focus position. There is provided an autofocus device characterized by comprising means.

  According to the present invention, since it is possible to notify the user whether or not the autofocus is based on the distance measurement, when the user determines that the autofocus based on the distance measurement is acceptable, the user can shoot as it is, while the focus detection is performed. If you wish to use autofocus, you can take pictures after taking measures such as reducing camera shake.

  The invention described in claim 13 is the invention described in any one of claims 5, 6 and 9, further comprising display means for displaying whether or not the distance measuring operation is in an on state. A featured autofocus device is provided.

  According to the present invention, since it is possible to notify the user whether or not the autofocus is accompanied by the distance measuring operation, when the user determines that the autofocus accompanied by the distance measuring operation is acceptable, the user can shoot as it is. Thus, when auto-focusing by focus detection without a distance measuring operation is desired, photographing can be performed after taking measures such as suppressing camera shake.

  The invention according to a fourteenth aspect is the invention according to any one of the first to thirteenth aspects, wherein the first in-focus position acquisition means is configured to detect the first focus by either triangulation or propagation time detection. An autofocus device characterized by acquiring a focus position is provided.

  According to a fifteenth aspect of the present invention, in the invention according to any one of the first to fourteenth aspects, the second in-focus position acquisition unit can perform the second alignment by either contrast detection or phase detection. An autofocus device characterized by acquiring a focal position is provided.

  According to a sixteenth aspect of the present invention, there is provided a camera comprising the autofocus device according to any one of the first to fifteenth aspects.

  According to a seventeenth aspect of the present invention, there is provided a photographing optical system having a focus lens, a light receiving element that receives light from a subject via the photographing optical system, a distance measuring sensor that measures a distance to the subject, and a camera shake amount. And a camera shake amount detecting means for detecting a step of measuring a distance to a subject by the distance measuring sensor and obtaining a first focus position of the focus lens corresponding to the measured distance. Receiving light from the subject via the photographing optical system by the light receiving element, performing focus detection based on an output signal of the light receiving element, and obtaining a second in-focus position of the focus lens; Detecting the amount of camera shake, and calculating the third focus position by weighting the first focus position and the second focus position based on the detected camera shake amount. It provides a Rugoase position determining step, and moving the focus lens in the third focus position, auto-focus method, which comprises a.

  According to an eighteenth aspect of the present invention, in the invention of the seventeenth aspect, in the in-focus position determining step, either the first in-focus position or the second in-focus position is set to the third in-focus position. An autofocus method is provided in which the third focus position is determined by selecting as a focus position.

  According to a nineteenth aspect of the present invention, in the seventeenth aspect of the present invention, the first in-focus position and the second in-focus position in the in-focus position determining step with respect to the magnitude of the amount of camera shake detected. Provided is an autofocus method characterized by continuously changing a weight for a focal position.

  According to a twentieth aspect of the present invention, there is provided a photographing optical system having a focus lens, a light receiving element that receives light from a subject through the photographing optical system, a distance measuring sensor that measures a distance to the subject, and a camera shake amount. Is an autofocus method using a camera shake amount detecting means for detecting an image, a photographing optical system having a focus lens, a light receiving element for receiving light from the subject via the photographing optical system, and measuring a distance to the subject An autofocus method using a distance measuring sensor and a camera shake amount detecting means for detecting a camera shake amount, the step of detecting the camera shake amount, and a distance measuring operation of the distance sensor based on the detected camera shake amount The first focusing position of the focus lens corresponding to the measurement distance of the distance measuring sensor when the distance measuring operation is in an on state. Obtaining a second in-focus position of the focus lens by performing focus detection based on an output signal of the light receiving element when the focus detection operation is in an on state; and When the distance operation is on, at least the first focus position is used to determine the position of the focus lens, whereas when the distance measurement operation is off, only the second focus position is determined. And a step of determining the position of the focus lens by using the method, and a step of moving the focus lens to the determined position.

  According to the present invention, it is possible to prevent an adverse effect on focusing accuracy due to camera shake, and to realize high-precision autofocus.

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

  FIG. 1 is a block diagram showing an example of the hardware configuration of the photographing apparatus according to the first to third embodiments of the present invention.

  In FIG. 1, a photographing apparatus 100 is a digital camera that electronically records an image, and includes a CPU (central processing unit) 10, an operation unit 12, a ROM 14, a SDRAM 16, a VRAM 18, an EEPROM 20, a photographing optical system 24, an image sensor 30, Timing generator 32, analog signal processing unit 34, A / D converter 36, image input controller 38, image signal processing unit 40, compression / decompression processing unit 42, media controller 44, memory card 46, display control unit 48, monitor 50, An AE detection unit 52, an AF detection unit 54, a strobe control unit 58, a strobe 60, a power supply control unit 62, a battery 64, an external light AF sensor 66, a camera shake amount detection unit 68, and the like are configured.

  The CPU 10 functions as a control unit that performs overall control of the overall operation of the photographing apparatus 100 and controls each part of the photographing apparatus 100 according to a predetermined program based on an input from the operation unit 12. In addition, the CPU 10 functions as an arithmetic processing unit for calculating various control values necessary for controlling the photographing apparatus 100, and executes various arithmetic processes according to a predetermined program. Each unit of the photographing apparatus 100 is connected to the CPU 10 via the bus 22.

  The ROM 14 stores programs executed by the CPU 10 and various data necessary for control. The SDRAM 16 is used as a work area for the CPU 10 and is also used as a temporary storage area for image data, and the VRAM 18 is used as a temporary storage area dedicated to image data for display. The EEPROM 20 stores various setting information unique to the user.

  The operation unit 12 includes various operation means such as a power button, a release button, a zoom button, a mode change switch, a menu button, a cross button, an execution button, and a cancel button, and signals to the CPU 10 according to the operation of these operation means. Output.

  The release button is a two-stroke type push button that can be pressed halfway and fully. When the release button is pressed halfway, the photographing apparatus 100 performs processing for photographing preparation such as automatic exposure (hereinafter also referred to as “AE”), autofocus (hereinafter also referred to as “AF”), and the like. When pressed, the actual shooting process is performed.

  Various settings of the photographing apparatus 100 are performed using the display of the monitor 50. That is, when the menu button is pressed, a setting screen for performing various settings of the photographing apparatus 100 is displayed on the monitor 50. The user performs various settings of the photographing apparatus 100 by operating the cross button, the execution button, and the cancel button in accordance with the screen display of the monitor 50.

  In addition to the shooting function for shooting an image, the shooting apparatus 100 has a playback function for playing back the shot image. Switching between the shooting mode and the playback mode is performed by a mode switch.

  The photographing optical system 24 includes a zoom lens 24z that performs zooming, a focus lens 24f that performs focusing, and a diaphragm 24i that performs light amount adjustment.

  The zoom lens 24z is driven by a zoom motor 26z and moves back and forth on the optical axis. Thereby, the subject image formed on the light receiving surface of the image sensor 30 is optically scaled. The CPU 10 controls the movement of the zoom lens 24z and the zoom by controlling the driving of the zoom motor 26z via the zoom motor driver 28z.

  The focus lens 24f is driven by the focus motor 26f and moves back and forth on the optical axis. Thereby, focusing is performed. The CPU 10 controls the movement of the focus lens 24f by controlling the drive of the focus motor 26f via the focus motor driver 28f, and performs focusing.

  The diaphragm 24i is constituted by, for example, an iris diaphragm, and is driven by an iris motor 26i to change its opening amount (aperture value). The CPU 10 controls the opening amount of the diaphragm 14i by controlling the driving of the iris motor 26i via the iris motor driver 28i, and controls the amount of subject light incident on the light receiving surface of the image sensor 30.

  The image sensor 30 is composed of a color CCD having a predetermined RGB color filter array, and is driven by a timing generator (TG) 32 to operate. That is, the signal charge accumulated in each pixel (photosensor) is read out by the drive pulse supplied from the timing generator 32 and output as an image signal. The CPU 10 controls the driving of the timing generator 32 to control the charge accumulation time (shutter speed) of the image sensor 30 and the reading of the image signal.

  The analog signal processing unit 34 performs correlated double sampling processing on the analog image signal output from the image sensor 30, and amplifies and outputs it.

  The A / D converter 36 converts the analog image signal output from the analog signal processing unit 34 into a digital image signal and outputs the digital image signal.

  The image input controller 38 has a built-in line buffer having a predetermined capacity. Under the control of the CPU 10, the image input controller 38 captures an image signal for one frame output from the A / D converter 36 and stores it in the SDRAM 16.

  The image signal processing unit 40 takes in an image signal stored in the SDRAM 16 under the control of the CPU 10 and performs a required signal processing to obtain an image signal (Y) and a color signal (Cr, Cb). Y / C signal).

  The compression / decompression processing unit 42 takes in an image signal (Y / C signal) under the control of the CPU 10 and performs predetermined compression processing to generate compressed image data (for example, JPEG). Further, under the control of the CPU 10, the compressed image data is captured and subjected to a predetermined expansion process to generate an uncompressed image signal (Y / C signal).

  The media controller 44 reads / writes data to / from the memory card 46 under the control of the CPU 10. For example, in response to a recording instruction from the CPU 10, image data obtained by photographing is recorded on the memory card 46. Also, corresponding image data is read from the memory card 46 in response to a read instruction from the CPU 10. The memory card 46 is detachably loaded in a card slot provided in the photographing apparatus main body.

  The display control unit 48 controls display on the monitor 50 under the control of the CPU 10. That is, an image signal (Y / C signal) is taken from the VRAM 18, converted into a display signal format, and output to the monitor 50. In addition, information such as predetermined characters, figures, symbols, etc. is superimposed on the image signal and output.

  The monitor 50 is composed of a color LCD, for example. The monitor 50 is used as a reproduction display unit for a captured image in the reproduction mode, and an image captured by the image sensor 30 is displayed through in the photographing mode, and is used as an electronic viewfinder.

  The AE detector 52 takes in R, G, and B image signals stored in the SDRAM 16 under the control of the CPU 10 and calculates an integrated value necessary for AE control. In the photographing apparatus 100 of the present embodiment, one screen is divided into a plurality of areas (for example, 8 × 8), and an integrated value of image signals for each of R, G, and B is calculated for each divided area. During the AE control, the CPU 10 obtains the brightness of the shooting scene based on the integrated value obtained from the AE detection unit 52, and determines the aperture value and the shutter speed (for example, using a program diagram). .

  The AF detection unit 54 takes in R, G, and B image signals stored in the SDRAM 16 under the control of the CPU 10 and calculates an AF evaluation value necessary for AF control. The AF detection unit 54 includes a high-pass filter that passes only a high-frequency component of the G signal, an absolute value processing unit, a focus area extraction unit that cuts out a signal within a predetermined focus area set on the screen, and the focus area The absolute value data in the focus area integrated by the integration unit is output to the CPU 10 as the AF evaluation value. During the AF control, the CPU 10 moves the focus lens 24f from the closest distance to infinity, acquires the AF evaluation value in small increments, and sets the peak position as the focus position (the position of the focus lens 24f that focuses on the main subject). The focus detection process to detect is performed. Then, the focus lens 24f is moved to the detected focus position.

  The strobe controller 58 controls the light emission of the strobe 60 under the control of the CPU 10. That is, the strobe 60 is caused to emit light at the light emission timing and the light emission amount instructed from the CPU 10.

  The strobe 60 is composed of, for example, a xenon tube. In addition, it can also comprise using LED.

  The power control unit 62 controls the supply of power from the battery 64 loaded in the apparatus main body to each unit of the photographing apparatus 100 in accordance with a command from the CPU 10.

  The external light AF sensor 66 is a sensor for measuring the distance to the subject. In this example, the passive type is not required to irradiate the subject with light for distance measurement, but the present invention is not limited to such a case. An active type that irradiates a subject with light for distance measurement (for example, infrared rays) may be used.

  The camera shake amount detection unit 68 detects the amount of camera shake. For example, the amount of camera shake is detected using an angular velocity sensor. The amount of camera shake may be detected by detecting a motion vector from the image signal obtained by the image sensor 30.

  In the following, the autofocus (which may be simply referred to as “AF”) of the photographing apparatus 100 of FIG. 1 will be described in detail.

  The autofocus is generally classified into a distance measurement method such as a triangulation method and a propagation time detection method, and a focus detection method such as a contrast detection method and a phase detection method. The photographing apparatus 100 according to the present embodiment is a hybrid type that uses two types of autofocus, that is, a ranging autofocus and a focus detection autofocus. As a distance measurement method, a triangulation method autofocus is performed in which distance measurement is performed by a passive external light AF sensor 66, and as a focus detection method, a contrast detection method for detecting the contrast of an image signal obtained by the image sensor 30 is used. Yes.

  FIG. 2 is a block diagram illustrating a main part of an example of the photographing apparatus according to the first embodiment. It should be noted that the same constituent elements (imaging optical system 24, imaging element 30, external light AF sensor 66, camera shake amount detection unit 68) as those of the imaging apparatus 100 shown in FIG.

  In FIG. 2, the photographing apparatus 100 a of the present embodiment is formed by a photographing optical system 24 having a focus lens (24 f in FIG. 1) and light from a subject via the photographing optical system 24. An image sensor 30 (light receiving element) that captures an image to be captured, an external light AF sensor 66 (ranging sensor) that measures the distance to the subject, a camera shake amount detection unit 68 that detects the amount of camera shake, and an external light AF sensor First focus position acquisition unit 102 that acquires the position of focus lens 24f corresponding to the distance measured by 66 (hereinafter referred to as “first focus position”), and an image signal output from image sensor 30 Calculated by the imaging processing unit 104 that performs predetermined signal processing, the AF evaluation value calculation unit 106 that calculates the AF evaluation value indicating the contrast of the image signal, and the AF evaluation value calculation unit 106. Based on the amount of camera shake detected by the second focus position acquisition unit 108 that acquires the position of the focus lens 24f at which the F evaluation value reaches the maximum value (hereinafter referred to as “second focus position”) and the camera shake amount detection unit 68. Then, a selection unit 110 (focus position) that selects either the first focus position acquired by the first focus position acquisition unit 102 or the second focus position acquired by the second focus position acquisition unit 108. And a position of the focus lens 24f selected by the selection unit 110 (which is either the first focus position or the second focus position, and may hereinafter be referred to as “third focus position”). The AF control unit 112 is configured to move the focus lens 24f of the optical system 24.

  For example, in shooting with a large amount of camera shake, the first focus position corresponding to distance measurement with little influence of camera shake is selected, and in shooting with a small amount of camera shake, the second focus position based on the contrast of the image signal is selected. .

  The correspondence between the components of the imaging apparatus 100a of the present embodiment shown in FIG. 2 and the components shown in FIG. 1 will be briefly described. The first focus position acquisition unit 102 and the second focus in FIG. The position acquisition unit 108, the selection unit 110, and the AF control unit 112 are mainly configured by the CPU 10 in FIG. 1, and the imaging processing unit 104 in FIG. 2 is mainly configured by the analog signal processing unit 34 and the A / D converter 36 in FIG. The AF evaluation value calculation unit 106 in FIG. 2 is mainly configured by the AF detection unit 54 and the CPU 10 in FIG. In FIG. 2, for convenience of illustration, motors (26f, 26i, and 26z in FIG. 1), motor drivers (28f, 28i, and 28z in FIG. 1) and the like that drive the photographing optical system 24 are omitted.

  FIG. 3 is a schematic flowchart showing a flow of an example of the autofocus process in the first embodiment. This process is executed according to a program by the overall control of the CPU 10 in FIG.

  First, in step S <b> 2, the first focus position acquisition unit 102 acquires first AF data indicating the first focus position corresponding to the distance measured by the external light AF sensor 66.

  Next, in step S <b> 4, the second focus position acquisition unit 108 acquires second AF data indicating the second focus position based on the contrast of the image signal obtained by the image sensor 30.

  Next, in step S6, the camera shake amount detection unit 68 detects the camera shake amount, and in step S8, it is determined whether or not the camera shake amount is larger than a predetermined threshold value.

  When the camera shake amount detection unit 68 is configured by an angular velocity sensor, for example, the absolute value of the motion vector obtained from the output signal of the angular velocity sensor is compared with a predetermined threshold value. A motion vector may be obtained from an image signal obtained by the image sensor 30 and the absolute value of the motion vector may be compared with a predetermined threshold value. Of course, the amount of camera shake may be detected by other known methods.

  When the amount of camera shake is larger than the threshold value, a first focus position corresponding to the measurement distance of the external light AF sensor 66 is selected in step S12. That is, the first AF data output from the first in-focus position acquisition unit 102 is selected by the selection unit 110. Further, a message (or icon) indicating that the first in-focus position by distance measurement by the external light AF sensor 66 is selected is displayed on the monitor (50 in FIG. 1). Display may be performed using a predetermined lamp.

  On the other hand, when the amount of camera shake is equal to or less than the threshold value, the second focus position based on the image contrast is selected in step S14. That is, the second AF data output from the second in-focus position acquisition unit 108 is selected by the selection unit 110. A message (or icon) indicating that the second focus position based on the image contrast is selected may be displayed on the monitor (50 in FIG. 1). Display may be performed using a predetermined lamp.

  In step S16, AF control is performed using the selected focus position (third focus position). That is, the focus lens 24f of the photographing optical system 24 is moved to the in-focus position selected by the selection unit 110.

  FIG. 4 is a block diagram illustrating a main part of an example of an imaging apparatus according to the second embodiment. In addition, the same code | symbol is attached | subjected to the same component as the imaging device 100a of 1st Embodiment shown in FIG. 2, The description is abbreviate | omitted about the content already demonstrated.

  The image capturing apparatus 100b according to the present embodiment has a first focus position and a second focus position acquisition unit 108 acquired by the first focus position acquisition unit 102 based on the camera shake amount detected by the camera shake amount detection unit 68. The weighting of the second in-focus position acquired in step (3) is performed, and the position (third in-focus position) for actually moving the focus lens of the photographing optical system 24 from the weighted first and second in-focus positions is obtained. A control unit 120 is provided. The weight control unit 120 is mainly configured by the CPU 10 of FIG.

  The AF control unit 112 moves the focus lens 24 f of the photographing optical system 24 to the third focus position obtained by the weighting control unit 120.

  FIG. 5 is a schematic flowchart showing a flow of an example of autofocus processing in the second embodiment. This process is executed according to a program by the overall control of the CPU 10 in FIG.

  First, in step S <b> 22, the first focus position acquisition unit 102 acquires AF data indicating the first focus position corresponding to the distance measured by the external light AF sensor 66.

  Next, in step S <b> 24, AF data indicating the second focus position based on the contrast of the image signal obtained by the image sensor 30 is acquired by the second focus position acquisition unit 108.

  Next, in step S26, the camera shake amount detection unit 68 detects the camera shake amount.

  Next, in step S28, according to the amount of camera shake, the use ratio of the AF data indicating the first focus position corresponding to the measurement distance and the AF data indicating the second focus position based on the contrast of the image signal is set. Control. That is, the first focus position acquired by the first focus position acquisition unit 102 and the second focus position acquired by the second focus position acquisition unit 108 are weighted, and the weighted first focus A third in-focus position is obtained from the position and the second in-focus position.

  In step S30, the focus lens 24f of the photographing optical system 24 is moved to the third in-focus position obtained by the weighting control unit 120.

  When the weight of the first in-focus position is greater than “0”, that is, when weighting is performed using the first in-focus position, a message indicating that weighting is performed using the first in-focus position. (Or icon) is displayed on the monitor (50 in FIG. 1). Display may be performed using a predetermined lamp.

  FIG. 6A shows an example of weighting in the second embodiment. In FIG. 6A, the horizontal axis is the amount of camera shake, and the vertical axis is the weight (0 to 1). A line denoted by reference sign w1 indicates a weight for the first in-focus position f1 output from the first in-focus position acquisition unit 102. A line denoted by reference sign w2 indicates a weight for the second in-focus position f2 output from the second in-focus position acquisition unit 108. The third focus position f3 that actually moves the focus lens 24f is obtained as f3 = w1 × f1 + w2 × f2.

  In the range where the amount of camera shake is less than or equal to M1, the weight w1 for the first focus position f1 is “0” and the weight w2 for the second focus position f2 is “1”. Therefore, the focus lens 24f is moved to the second focus position f2.

  In the range where the amount of camera shake is larger than M1 and smaller than M2, the weight w1 for the first in-focus position f1 and the weight w2 for the second in-focus position f2 are both larger than “0” and smaller than “1”. Accordingly, the focus lens 24f is moved to a position between the first focus position f1 and the second focus position f2.

  In the range of camera shake amounts M1 to M2, the weights w1 and w2 continuously change with respect to the amount of camera shake. If the camera shake amount changes in time series, the weights w1 and w2 continuously change according to the change in the camera shake amount. In FIG. 6A, the case where the weights w1 and w2 change linearly with respect to the amount of camera shake is shown as an example, but may be changed in a curved line.

  In a range where the amount of camera shake is M2 or more, the weight w1 for the first focus position f1 is “1”, and the weight w2 for the second focus position f2 is “0”. Accordingly, the focus lens 24f is moved to the first focus position f1.

  The auto focus of the image capturing apparatus 100b of the present embodiment will be described in comparison with the auto focus of the image capturing apparatus 100a of the first embodiment shown in FIG.

  FIG. 6B shows the operation of the selection unit (110 in FIG. 1) in the first embodiment in relation to the amount of camera shake and the weight. In the first embodiment, as shown in FIG. 6B, when the amount of camera shake is equal to or less than the threshold value Mth, the weight w1 for the first focus position f1 is “0” and the weight w2 for the second focus position f2 is “ 1 ”, and the focus lens 24f is moved to the second focus position f2. When the amount of camera shake is larger than the threshold value Mth, the weight w1 for the first focus position f1 is “1”, the weight w2 for the second focus position f2 is “0”, and the focus lens 24f is moved to the first focus position f1. Is moved.

  On the other hand, in the second embodiment, as shown in FIG. 6A, both the first in-focus position f1 and the second in-focus position f2 are used in the range of camera shake amounts M1 to M2. At the same time, the weights w1 and w2 are continuously changed with respect to the amount of camera shake. Specifically, when the detected amount of camera shake is m, in the range of M1 <m <M2, the ratio (weight) of the first in-focus position f1 obtained by ranging is increased as the amount of camera shake increases. As the amount of camera shake is smaller, the ratio (weight) of the second focus position f2 obtained by focus detection is increased to obtain the third focus position.

  For example, the correspondence between the camera shake amount and the weight shown in FIG. 6A is stored as table information in the ROM 14 (or EEPROM 20) in FIG. 1, and the table information is read during autofocus to perform autofocus. .

  7A and 7B schematically show the relationship between the image obtained by the image sensor 30 and the amount of camera shake. In FIG. 7A, the absolute value of the motion vector due to camera shake from the reference frame 71 (image corresponding to a certain moment in the time series) to the next frame 72 in the time series. Corresponds to the amount of camera shake m in FIG. FIG. 7B shows a state in which the frames 71 and 72 are overlapped.

  When the amount of camera shake is obtained from the image signal obtained by the image sensor 30, the scale (number of pixels) of the amount of camera shake varies depending on the resolution of the image signal. Therefore, in this example, the amount of camera shake in FIG. 6A is the ratio of the number of pixels indicating the absolute value of the motion vector to the total number of pixels of the image sensor 30 in a specific direction (for example, the longitudinal direction of the image sensor 30) ( Pixel number ratio, unit is%). For example, both M1 and M2 are 5% or less.

  FIG. 8 is a block diagram illustrating a main part of an example of an imaging apparatus according to the third embodiment. In addition, the same code | symbol is attached | subjected to the same component as the imaging device 100a of 1st Embodiment shown in FIG. 2, The description is abbreviate | omitted about the content already demonstrated.

  The imaging apparatus 100c according to the present embodiment includes an on / off control unit that switches on / off operations of the first focus position acquisition function and the second focus position acquisition function based on the camera shake amount detected by the camera shake amount detection unit 68. 130 and the second in-focus position during the operation of the first in-focus position acquisition function 102 acquired by the first in-focus position acquisition unit 102 during the operation of the first in-focus position acquisition function. A data control unit 132 is provided that determines a position (third in-focus position) for actually moving the focus lens of the photographing optical system 24 from the second in-focus position acquired by the acquisition unit 108. The data control unit 132 is mainly configured by the CPU 10 of FIG.

  The AF control unit 112 moves the focus lens 24 f of the photographing optical system 24 to the third focus position determined by the data control unit 132.

  In determining the third in-focus position by the data control unit 132, as shown in FIG. 6A, when the camera shake amount is larger than M1 and smaller than M2, both the first in-focus position and the second in-focus position are determined. There are a mode in which the third in-focus position is obtained by using and a mode in which either the first in-focus position or the second in-focus position is selected as shown in FIG. 6B.

  In the aspect shown in FIG. 6A, the on / off control unit 130 sets the first focus position acquisition function to off and sets the second focus position acquisition function to on when the camera shake amount is M1 or less. When the camera shake amount is larger than M1 and smaller than M2, both the first focus position acquisition function and the second focus position acquisition function are set to ON, and when the camera shake amount is M2 or more, the first focus position is set to ON. The focus position acquisition function is set to ON and the second focus position acquisition function is set to OFF.

  In the aspect shown in FIG. 6B, the on / off control unit 130 sets the first focus position acquisition function to off and sets the second focus position acquisition function to on when the camera shake amount is equal to or less than Mth. When the amount of camera shake is larger than Mth, the first focus position acquisition function is set to ON and the second focus position acquisition function is set to OFF.

  The on / off control unit 130 turns on / off the distance measuring operation of the external light AF sensor 66 based on the detected amount of camera shake as the first focus position acquisition function is turned on / off. For example, switching between power supply to the external light AF sensor 66 or power supply stop is performed. Note that in the case of an active type in which distance measurement is performed by irradiating light on a subject, on / off of light irradiation on the subject may be switched.

  The on / off control unit 130 turns on / off the focus detection operation of the AF evaluation value calculation unit 106 based on the detected amount of camera shake as on / off of the second focus position acquisition function. In the present embodiment, the focus is detected by detecting the contrast of the image signal obtained by the image sensor 30, and the contrast detection operation is turned on / off. In the contrast detection off state, the focus lens 24f for contrast detection is not moved in small increments. When the live view display is not performed, the power supply to the image sensor 30 may be switched or the power supply may be stopped.

  FIG. 9 is a schematic flowchart showing a flow of an example of the autofocus process in the third embodiment. This process is executed according to a program by the overall control of the CPU 10 in FIG.

  First, in step S42, the camera shake amount detection unit 68 detects the camera shake amount.

  Next, in step S44, it is determined whether or not the amount of camera shake is larger than a predetermined threshold value.

  When the amount of camera shake is larger than the threshold value, in step S46, the distance measurement function of the external light AF sensor 66 is set to the on state, and the contrast detection function of the AF evaluation value calculation unit 106 is set to the off state, and in step S48. Then, AF data (indicating the first in-focus position) corresponding to the distance measured by the external light AF sensor 66 is acquired.

  A message (or icon) indicating that the distance measuring operation of the external light AF sensor 66 is on is displayed on the monitor (50 in FIG. 1). Display may be performed using a predetermined lamp.

  On the other hand, when the amount of camera shake is equal to or less than the threshold value, in step S50, the distance measurement function of the external light AF sensor 66 is set to an off state, and the contrast detection function of the AF evaluation value calculation unit 106 is set to an on state. In step S52, AF data (indicating the second in-focus position) based on the AF evaluation value indicating the contrast of the image signal is acquired.

  A message (or icon) indicating that the contrast detection function (focus detection operation) is on may be displayed on the monitor (50 in FIG. 1). Display may be performed using a predetermined lamp.

  In step S54, the focus lens 24f of the photographing optical system 24 is moved to the third in-focus position selected by the data control unit 132.

  FIG. 10 is a block diagram showing an example of the hardware configuration of the photographing apparatus according to the fourth to sixth embodiments of the present invention. In FIG. 10, the same components as those of the image capturing apparatus 100 of FIG. 1 are denoted by the same reference numerals, and the description of the contents already described is omitted.

  An imaging apparatus 1000 illustrated in FIG. 10 includes a camera shake correction unit 200 that performs optical camera shake correction. The camera shake correction unit 200 controls the camera shake correction mechanism 201 that moves the image stabilization lens 24c in the photographic optical system 24, and the camera shake correction control that performs the camera shake correction by controlling the camera shake correction mechanism 201 and moving the image stabilization lens 24c. The unit 202 is configured to be included. Details of the vibration-proof lens 24c, the camera shake correction mechanism 201, and the camera shake correction control unit 202 will be described later.

  The camera shake correction unit 200 calculates a camera shake correction amount based on the camera shake amount detected by the camera shake amount detection unit 68. In this example, the camera shake amount detection unit 68 detects the angular velocity of the photographing apparatus 1000 (particularly, the angular velocity of the photographing optical system 24), and calculates the movement amount of the image stabilizing lens 24c based on the angular velocity. However, it is necessary to move the vibration-proof lens 24c within the movable range. Within the movable range of the anti-vibration lens 24c, the anti-vibration lens 24c can be moved by a lens movement amount equivalent to the amount of camera shake (a lens movement amount calculated from the angular velocity).

  Further, the camera shake correction unit 200 of this example has a correction limiting function that limits camera shake correction and prevents overcorrection. In the correction restriction function, even if the movement destination of the image stabilization lens 24c corresponding to camera shake is within the movable range on the mechanism, the actual lens is not within the movable range restricted to prevent overcorrection. The movement amount (which is a camera shake correction amount) is reduced, or the movement of the image stabilizing lens 24c is stopped. For example, when the image capturing apparatus 1000 is panning, correction correction is performed so as not to overcorrect.

  The present invention will be described by way of an example in which camera shake correction is performed by moving the image stabilizing lens 24c. However, the present invention is a mode in which camera shake correction is performed by moving the image sensor 30, or a mode in which camera shake correction is performed by image processing ( So-called electronic).

  FIG. 11 is a block diagram illustrating a main part of an example of the imaging apparatus 1000a according to the fourth embodiment. Note that the same components as those of the image capturing apparatus 100b of the second embodiment shown in FIG. 4 are denoted by the same reference numerals, and description of the contents already described is omitted.

  In FIG. 11, the weighting control unit 140 obtains the first in-focus position acquisition unit 102 based on the camera shake amount detected by the camera shake amount detection unit 68 and the camera shake correction amount by the camera shake correction unit 200. The third focus position is obtained by weighting the first focus position and the second focus position acquired by the second focus position acquisition unit 108. As already described in the first embodiment and the second embodiment, the first focus position is a focus position corresponding to the measurement distance of the external light AF sensor 66 (ranging sensor), and the second focus position. Is a focus position acquired by focus detection using an output signal (image signal) of the image sensor 30. The weighting control unit 140 weights the first focus position and the second focus position to obtain a position (third focus position) at which the focus lens 24f of the photographing optical system 24 is actually moved. The weighting control unit 140 is mainly configured by the CPU 10 of FIG.

  The weighting control unit 140 of this example weights the first in-focus position and the second in-focus position when the amount of camera shake exceeds a threshold value indicating a limit value or limit value for camera shake correction in the camera shake correction unit 200. If the amount of camera shake does not exceed the threshold value, the second focus position is set as the third focus position. In this example, the limit value of camera shake correction indicates the maximum movable range (hereinafter referred to as “operation range”) of the image stabilizing lens 24c. The limit value for camera shake correction indicates a movable range (hereinafter referred to as “limit range”) of the image stabilization lens 24c when the movement of the image stabilization lens 24c is limited.

  FIG. 12 is a schematic flowchart showing a flow of an example of autofocus processing in the fourth embodiment. This process is executed according to a program by the overall control of the CPU 10 in FIG.

  Steps S62 and S64 are the same as steps S22 and S24 in the second embodiment.

  In step S 66, the camera shake amount is acquired from the camera shake amount detection unit 68 and the camera shake correction amount is acquired from the camera shake correction unit 200. For example, the camera shake amount is a lens movement amount of the image stabilizing lens 24 c obtained from the angular velocity, and the camera shake correction amount is an actual lens movement amount determined by the camera shake correction unit 200.

  Next, in step S68, the first in-focus position and the second in-focus position are weighted, and the third in-focus position is obtained from the weighted first in-focus position and second in-focus position. Such weighting is performed when the amount of camera shake exceeds a threshold value indicating the limit value or limit value of camera shake correction in the camera shake correction unit 200, and when the camera shake amount does not exceed the threshold value, the second in-focus position by focus detection. It is preferable to use only.

  In step S70, the focus lens 24f of the photographing optical system 24 is moved to the third focus position.

  During the operation of the correction limiting function, for example, the weighting shown in FIG. During the operation of the correction limit function, a camera shake correction limit value (a value smaller than the limit value) is set. When the amount of camera shake m is equal to or less than M1, the image stabilization lens 24c is moved by the amount of camera shake. Smaller than (the lens movement amount calculated based on the angular velocity). M1 uses a limit value indicating a boundary of whether or not to perform correction limitation for preventing overcorrection. M2 uses a limit value indicating the maximum movable range of the vibration-proof lens 24c. FIG. 13 shows a correspondence relationship between the difference d (= mc) between the camera shake amount m and the camera shake correction amount c and the weights w1 and w2. During the operation of the correction limiting function, as the difference d increases, the weight w1 of the first focus position corresponding to the measurement distance of the external light AF sensor 66 is increased, while the second focus by focus detection using an image signal is increased. The position weight w2 is reduced. That is, when the amount of camera shake is large, the amount of camera shake correction is made smaller than the amount of camera shake in order to prevent overcorrection, and the weight w1 of the first in-focus position is increased as the amount of camera shake increases.

  Further, for example, weighting shown in FIG. 6B is performed while the correction limiting function is not operating. As the threshold value Mth, a limit value of the amount of camera shake is used. In this case, when the amount of camera shake is equal to or less than the limit value, the weight w1 for the first focus position is set to “0”, and the weight w2 for the second focus position is set to “1”. On the other hand, when the amount of camera shake exceeds the limit value, the weight w1 for the first focus position is set to “1”, and the weight w2 for the second focus position is set to “0”. That is, when the amount of camera shake exceeds the limit value, autofocus is performed using the first focus position.

  6A and 6B, the case where w1 = 1 is set when the amount of camera shake exceeds the limit value of camera shake correction has been described as an example. However, when the limit value of camera shake correction is exceeded. You may make it change w1 continuously within the range of 1 or less.

  FIG. 14 is a block diagram illustrating a main part of an example of an imaging apparatus 1000b according to the fifth embodiment. In addition, the same code | symbol is attached | subjected to the same component as the imaging device 1000a of 4th Embodiment shown in FIG. 11, The description is abbreviate | omitted about the already demonstrated content.

  The imaging apparatus 1000b of the present embodiment compares the camera shake amount detected by the camera shake amount detection unit 68 with the limit value and limit value of the camera shake correction amount by the camera shake correction unit 200, and compares the first focus position and the first focus position. A selection unit 150 (focus position determination unit) that selects one of the two focus positions is provided. The selection unit 150 is mainly configured by the CPU 10 of FIG.

  The selection unit 150 of the present example, when the amount of camera shake exceeds a limit value or a limit value of camera shake correction in the camera shake correction unit 200, the first focus position corresponding to the measurement distance of the external light AF sensor 66 On the other hand, when the amount of camera shake does not exceed the threshold, the second in-focus position by focus detection using an image signal is selected.

  The flow of autofocus processing in the fifth embodiment will be described using the flowchart of FIG. In the following description, it is assumed that the correction limit function for preventing overcorrection is in operation and that a limit value for camera shake correction (a value smaller than the limit value) is set.

  Steps S2 to S6 are the same as in the first embodiment.

  The selection unit 150 of this example compares the camera shake amount detected by the camera shake amount detection unit 68 with the limit value of the camera shake correction amount (step S8), and the camera shake amount detected by the camera shake amount detection unit 68 is the camera shake correction. When the amount limit value is exceeded, the first focus position is selected (step S12), and when the camera shake amount is less than or equal to the camera shake correction amount limit value, the second focus position is selected (step S14). Then, the focus lens 24f of the photographic optical system 24 is moved to the in-focus position selected by the selection unit 150 (step S16).

  Note that, in a state where the correction limiting function for preventing overcorrection is not operating, the selection unit 150 of this example compares the camera shake amount with the limit value of the camera shake correction amount.

  FIG. 15 is a block diagram illustrating a main part of an example of the imaging apparatus 1000c according to the sixth embodiment. In addition, the same code | symbol is attached | subjected to the same component as the imaging device 1000a of 4th Embodiment shown in FIG. 11, The description is abbreviate | omitted about the already demonstrated content.

  The imaging apparatus 1000c according to the present embodiment includes an on / off control unit 160 that switches on and off the operations of the first focus position acquisition function and the second focus position acquisition function, and the first focus position and the second focus position. A data control unit 162 that determines a position (third in-focus position) for actually moving the focus lens of the photographing optical system 24 is provided. The data control unit 162 is mainly configured by the CPU 10 of FIG. The AF control unit 112 moves the focus lens 24 f of the photographing optical system 24 to the third focusing position determined by the data control unit 162.

  In this example, when the amount of camera shake exceeds the limit value or the limit value indicating the camera shake correction value in the camera shake correction unit 200, the on / off control unit 160 performs the first focus position acquisition function (ranging operation). On the other hand, when the camera shake amount does not exceed the threshold value while the on state is set, the first focus position acquisition function is set to the off state.

  As shown in FIG. 6A, the third in-focus position is determined by using both the first in-focus position and the second in-focus position when the amount of camera shake is M1 to M2. There are a mode for obtaining the position and a mode for selecting one of the first focus position and the second focus position as shown in FIG.

  During the operation of the correction limiting function, for example, the weighting shown in FIG. During the operation of the correction limit function, a camera shake correction limit value (a value smaller than the limit value) is set. M1 uses a limit value indicating a boundary of whether or not to perform correction limitation for preventing overcorrection. M2 uses a limit value indicating the maximum movable range of the vibration-proof lens 24c. When the camera shake amount is equal to or less than M1 (limit value), the on / off control unit 160 sets the first focus position acquisition function to off and sets the second focus position acquisition function to on. When the amount of camera shake is larger than M1 (limit value) and smaller than M2 (limit value), both the first focus position acquisition function and the second focus position acquisition function are set to ON. When the amount of camera shake is equal to or greater than M2 (limit value), the first focus position acquisition function is set on and the second focus position acquisition function is set off.

  Further, for example, weighting shown in FIG. 6B is performed while the correction limiting function is not operating. As the threshold value Mth, a limit value of the amount of camera shake is used. When it is equal to or less than Mth (limit value), the on / off control unit 160 sets the first focus position acquisition function to off and sets the second focus position acquisition function to on. When the amount of camera shake is larger than Mth (limit value), the first focus position acquisition function is set to on and the second focus position acquisition function is set to off.

  In the first to sixth embodiments, there are various display modes on the monitor 50. A mode for displaying which focus position is selected from the first focus position and the second focus position, a mode for displaying whether weighting using the first focus position is performed, and a measurement There is a mode for displaying whether or not the distance operation is in an on state.

  In the description from the first embodiment to the sixth embodiment, a triangulation method that performs distance measurement using passive external light is used as an example of a ranging autofocus, and an example of a focus detection autofocus. The case of using the contrast detection method for detecting the contrast using the image signal has been described as an example, but the present invention is not particularly limited to such a case.

  Ranging autofocus includes a passive method that does not require light irradiation from the camera side and an active method that irradiates light from the camera toward the subject. In the case of the passive method, for example, as described above, distance measurement is performed based on the same principle as triangulation, and autofocus is performed (passive triangulation method). In the case of the active method, for example, the subject is irradiated with infrared rays, and the distance is measured by the time it returns to the camera after being reflected by the subject, and autofocus is performed (active propagation time detection method). Ranging may be performed using sound waves instead of light. Of course, the distance may be measured by methods other than these.

  For focus detection autofocus, in addition to the contrast detection method that detects the contrast of the image signal output from the image sensor and performs autofocus as described above, light from the subject is received via the imaging optical system. There is a phase detection method in which the focus is detected by comparing the phase of an image on a light receiving element. Of course, focus detection may be performed by methods other than these. In the phase detection method, for example, a sensor array in which sensors are arranged in a row is used as a light receiving element. An aerial image by the imaging optical system is re-imaged on the two sensor arrays, and the output signals of the two sensor arrays are compared.

  When the phase detection method is used as the autofocus of the focus detection method, the focus position (first focus position) acquired by the distance measurement method and the focus position (second focus position) acquired by the phase detection method are used. Then, a focus position (third focus position) for actually moving the focus lens of the photographing optical system is obtained. Either the first focusing position or the second focusing position may be selected as the third focusing position.

  Of course, the autofocus according to the present invention can be applied to continuous AF that performs continuous autofocus.

<Image stabilization unit>
A specific example of the camera shake correction unit 200 in FIG. 10 will be described below.

  In FIG. 10, the user can switch the camera shake correction on mode and the camera shake correction off mode with the operation unit 12 in the photographing apparatus 100. In this example, when the camera shake correction on mode is instructed and input to the operation unit 12, the camera shake correction control unit 202 controls the camera shake correction mechanism 201 to perform so-called optical camera shake correction. In the camera shake correction on mode, control is performed to move the image stabilizing lens 24c of the photographing optical system 24 so that camera shake is canceled. In the camera shake correction off mode, control for stopping the image stabilizing lens 24c of the photographing optical system 24 is performed.

  FIG. 16 is a cross-sectional view schematically showing an example of the structure of the photographic optical system 24. The photographic optical system 24 of this example is arranged along the optical axis 24a from the subject side in the order of a fixed lens 24s, a zoom lens 24z, an anti-vibration lens 24c, an aperture 24i, and a focus lens 24f.

  A CCD (Charge Coupled Device) as the image sensor 30 is disposed on the optical axis 24a of the photographing optical system 24, and light incident on the light receiving surface of the image sensor 30 through the lens groups (24s, 24z, 24c, 24f). The subject image is converted into an electrical signal (analog image signal).

  When camera shake occurs, the subject image moves on the CCD 30 within one frame, so that an electrical signal of a blurred image is generated from the CCD 30. In order to detect the occurrence of the camera shake, a horizontal (X direction) angular velocity sensor (gyro sensor) 250 (see FIG. 20) and a vertical direction (Y) are installed in the camera body or the lens assembly having the photographing optical system 24. Direction) angular velocity sensor (not shown). These angular velocity sensors output signals representing the angular velocities of the imaging apparatus 1000 in the X direction and the Y direction, respectively. Alternatively, a gyro sensor that outputs a signal representing angular acceleration may be used.

  When camera shake does not occur, the optical axis of the vibration-proof lens 24c coincides with the optical axis 24a of the photographing optical system 24. When camera shake is detected by the angular velocity sensor 250 in the X direction and / or the angular velocity sensor in the Y direction, the anti-vibration lens 24c moves in a direction orthogonal to the optical axis 24a of the photographing optical system 24 according to the size and direction of the camera shake. Moving. As a result, the image formed on the CCD 30 is almost stopped, and a signal representing a sharp image is output from the image sensor 30.

  Next, the camera shake correction mechanism 201 will be described.

  FIG. 17 is an exploded perspective view showing the camera shake correction mechanism 201, and FIG. 18 is a front view of the camera shake correction mechanism 201 with the cover removed. FIG. 19 is a cross-sectional view of a main part of the camera shake correction mechanism 201.

  17 and 18, the lens housing 315 is a structure that houses a lens including the vibration-proof lens 24c. Although not shown, lenses (24s, 24z, 24f in FIG. 16) other than the image stabilizing lens 24c are also stored in the lens storage body 315. The lens housing 315 is fixed to the housing of the photographing apparatus 1000. The lens housing 315 is provided with a main guide shaft 316 extending in the X direction and a main guide shaft 317 extending in the Y direction, and an X slider 318 movable in the X direction, and a Y guide in the Y direction. A movable Y slider 319 is accommodated. The X slider 318 and the Y slider 319 are substantially L-shaped when viewed from the plane.

  A pair of shaft holes 318a are formed in the X slider 318, and these shaft holes 318a are fitted to the main guide shaft 316 in a slider bullet. Similarly, the pair of shaft holes 319 a of the Y slider 319 are fitted to the main guide shaft 317 in the slider bullet.

  The X slider 318 has a pair of shaft holes 318b. The shaft hole 318b is fitted in the slider bullet on the sub guide shaft 320 extending in the Y direction. A pair of shaft holes 319b of the Y slider 319 are fitted in the slider bullet on the sub guide shaft 321 extending in the X direction.

  A flat ring-shaped coil 322 is attached to the X slider 318. Similarly, a coil 323 is attached to the Y slider 319. A yoke 325 having a permanent magnet 326 attached inside is attached to the lens housing 315 in order to generate an X-direction electromagnetic force with the coil 322. Note that a yoke and a permanent magnet for generating an electromagnetic force in the Y direction between the coil 323 are omitted in the drawing.

  The lens holder 330 holds the vibration-proof lens 24c. A pair of holes 330a are formed in the lens holder 330, and both ends of the sub-guide shaft 321 extending in the X direction are fitted to the lens holder 330, and fixed with an adhesive or the like so that the sub-guide shaft 321 does not move. Has been. Similarly, the sub guide shaft 320 is firmly held in the pair of holes 330b.

  A cover 332 is disposed on the lens holder 330 so as to hide the sliders 318 and 319. The cover 332 is placed on the step 315a of the lens housing 315. Two permanent magnets 333 and 334 are attached to the inner surface of the cover 332. The permanent magnet 333 faces the yoke 325, and the permanent magnet 334 faces another yoke (not shown).

  As shown in FIG. 19, permanent magnets 326 and 333 are located on both sides of the coil 322, and a bent piece 325 a of the yoke 325 enters the coil 322. When the coil 322 is energized, an electromagnetic force is generated by the magnetic field generated in the coil 322 and the magnetic fields of the permanent magnets 326 and 333. This electromagnetic force acts in the + X direction or the −X direction according to the direction of the current of the coil 322, and moves the X slider 318 in the + X direction or the −X direction. Similarly, when the coil 323 is energized, the Y slider 319 is moved in the + Y direction or the −Y direction by an electromagnetic force generated from a magnetic field generated in the coil 323 and a permanent magnet (not shown) and a magnetic field of the permanent magnet 334.

  In addition, the X hall element 340 and the Y hall element 341 are housed in the holes 315 b and 315 c of the lens housing body 315. X Hall element 340 generates a voltage in response to the magnetic field of small magnet 342 embedded in the lower surface of X slider 318. This voltage corresponds to the position of the X slider 318 in the X direction. The Y Hall element 341 also generates a voltage in response to the magnetic field of the magnet 343 embedded in the lower surface of the Y slider 319, and this voltage corresponds to the position of the Y slider 319 in the Y direction.

  Each Hall element 340, 341 generates a signal in a voltage range of 0 to 5 V, for example, according to the position of the vibration-proof lens 24c. When the output signals of the Hall elements 340 and 341 are 2.5 V (reference voltage), the X slider 318 is located at the X reference position and the Y slider 319 is located at the Y reference position. In this state, the optical axis of the vibration-proof lens 24c coincides with the optical axis 24a of the photographing optical system 24.

  Next, the operation of the camera shake correction mechanism 201 will be described.

  When the power of the photographing apparatus 1000 is turned on to prepare for photographing, the camera shake correction control unit (202 in FIG. 10) uses the reference voltage (2.5 V) as a control target value signal. Then, the camera shake correction control unit 202 feedback-controls the direction and magnitude of the current supplied to the coils 322 and 323 so that the output signals of the hall elements 340 and 341 reach the reference voltage that is the control target value signal. . By this feedback control, the X slider 318 is moved toward the X reference position, and the Y slider 319 is moved toward the Y reference position. When the sliders 318 and 319 are set at the reference position, the optical axis of the image stabilizing lens 24c coincides with the optical axis 24a of the photographing optical system 24. In the camera shake correction off mode, the control target value signal is maintained at the reference voltage even if there is camera shake. As a result, the lens holder 330 remains stopped even if camera shake occurs.

  In the camera shake correction on mode, the anti-vibration lens 24c moves together with the lens holder 330 in accordance with camera shake. Camera shake in the X direction is detected by the angular velocity sensor 250 in the X direction, and camera shake in the Y direction is detected by the angular velocity sensor in the Y direction. When camera shake occurs, each angular velocity sensor generates an angular velocity signal. The angular velocity signals of the respective angular velocity sensors are individually integrated and converted into angle signals in the X direction and the Y direction, respectively. This angle signal is converted into a lens displacement amount signal corresponding to the linear movement of the image stabilizing lens 24c for correcting image blur corresponding to this angle (shake angle). The obtained lens displacement amount signal is added to the reference voltage (2.5 V) to become a control target value signal.

  Here, since the lens displacement amount signal has a positive or negative sign according to the direction of camera shake, the control target value signal changes around the reference voltage (2.5 V).

  For example, when camera shake occurs in the + X direction, a lens displacement amount signal for correcting the camera shake is added to the reference voltage, and a control target value signal is calculated. Next, the direction and magnitude of the current of the coil 322 are determined so that the output signal of the Hall element 340 in the X direction becomes the control target value signal. The electromagnetic force in the −X direction acts on the coil 322 by the magnetic field generated by energization of the coil 322 and the magnetic fields of the permanent magnets 326 and 333. Due to this electromagnetic force, the X slider 318 moves in the −X direction along the main guide shaft 316. Further, since the X slider 318 is connected to the lens holder 330 via the sub guide shaft 320, the X slider 318 pushes the lens holder 330 in the −X direction.

  Here, the sub guide shaft 321 fixed to the lens holder 330 is guided by the shaft hole 319 b of the Y slider 319. Accordingly, the X slider 318 and the lens holder 330 move together while being guided by the pair of shaft holes 319a of the main guide shaft 316 and the Y slider 319.

  When the X slider 318 moves to the lens position corresponding to the control target value signal, the output signal of the Hall element 340 in the X direction matches the control target value signal. As a result, the image formed on the CCD 30 hardly moves. Accordingly, a clear image electrical signal is generated from the CCD 30.

  When the camera shake is stopped, the lens displacement amount signal is controlled to gradually return to 0. As a result, the control target value signal becomes the reference voltage (2.5 V), and the output signal of the hall element 340 in the X direction becomes the reference voltage. To return, the direction and magnitude of the current in the coil 322 is determined. As a result, the X slider 318 gradually moves toward the X reference position. After the X slider 318 returns to the X reference position, the direction and magnitude of the current of the coil 322 are controlled so that the X reference position is maintained. Since the lens holder 330 returns together with the X slider 318, the optical axis of the vibration-proof lens 24c is in a state where it matches the optical axis 24a of the photographing optical system 24.

  When camera shake in the −X direction occurs, a positive lens displacement signal having a value corresponding to the magnitude of camera shake is added to the reference voltage, and a control target value signal is calculated. The direction and magnitude of the current of the coil 322 are determined so that the output signal of the Hall element 340 in the X direction becomes the control target value signal. When the coil 322 is energized, the X slider 318 moves in the + X direction along the main guide shaft 316. When there is no camera shake in the −X direction, the X slider 318 gradually returns to the X reference position, and the X slider 318 is maintained at the X reference position. At this time, the optical axis of the image stabilizing lens 24c coincides with the optical axis 24a of the photographing optical system 24.

  The same applies to camera shake in the Y direction. In response to camera shake in the Y direction, the Y slider 319 is moved in the Y direction by the coil 323. At this time, the lens holder 330 is pushed in the Y direction via the sub guide shaft 321. The Y slider 319 is guided by the main guide shaft 317, and the sub guide shaft 320 of the lens holder 330 is guided by the shaft hole 318 b of the X slider 318. When the lens holder 330 moves in the Y direction together with the Y slider 319, image movement due to camera shake in the Y direction is prevented, and the image formed on the CCD 30 substantially stops. When there is no camera shake in the Y direction, the Y slider 319 is gradually returned to the Y reference position.

  Since actual camera shake occurs in both the X direction and the Y direction, the lens holder 330 moves simultaneously in both the X direction and the Y direction.

  Next, the camera shake correction control unit 202 will be described.

  FIG. 20 is a block diagram mainly showing an embodiment of the internal configuration of the camera shake correction control unit 202 shown in FIG. Note that the camera shake correction control unit 202 includes two systems, a horizontal (X direction) camera shake correction control unit and a vertical (Y direction) camera shake correction control unit. Therefore, only the camera shake correction control unit in the X direction is shown.

  In FIG. 20, an X-direction angular velocity sensor 250 detects an angular velocity in the horizontal direction (X direction) of the photographing apparatus 1000, and sends an angular velocity signal (voltage signal) corresponding to the detected angular velocity to an analog high-pass filter (HPF) 204. Output. The HPF 204 removes the DC component of the input angular velocity signal and outputs it to the AD converter 208 via the analog amplifier 206.

  The AD converter 208 converts the input analog angular velocity signal into a digital angular velocity signal and outputs it to the digital HPF 210. The HPF 210 includes a low-pass filter (LPF) 210A that detects DC (reference value) and a subtractor 210B. The subtractor 210B subtracts the reference value detected by the LPF 210A from the angular velocity signal. As a result, low-frequency angular velocity signals that cannot be regarded as camera shake are removed.

  The angular velocity signal output from the digital HPF 210 is integrated by the integration circuit 212 and converted into an angle (deflection angle) signal here.

That is, the integration circuit 212 first integrates the input angular velocity signal A1 and converts it to an angle signal _{An + 1} . The following equation is used for this integration.

[Equation 1]
A _{n + 1} = (A ₁ −A _n ) × α + A _n
Here, α is a coefficient, and _An is the previous integrated value read from the register.

By the above integration, the tilt angle of the optical system caused by camera shake is calculated. The obtained angle signal _{An + 1} is sent to the integration limiter 214. When the inclination angle exceeds the limit angle, the integration limiter 214 cuts the excess portion. Therefore, the maximum value of the angle signal _{An + 1} is the limit angle.

  The limit angle of the integration limiter 214 (restriction values of the upper limit value and the lower limit value of the swing angle) is given from the controller 240, and details of the limit value will be described later.

  The angle signal output from the integration limiter 214 is applied to the phase compensation circuit 216. The phase compensation circuit 216 performs delay compensation for an angle signal that is delayed from the actual angle by the above calculation or the like.

  The angle-compensated angle signal is applied to the control target value calculation circuit 218, which indicates the lens position in the X direction to which the image stabilizing lens 24c for correcting image blur due to camera shake of the photographing apparatus 1000 is to be moved. Converted to control target value.

  The control target value calculated by the control target value calculation circuit 218 is added to the control target value limiter 220. In the control target value limiter 220, limit values indicating the upper limit value and the lower limit value of the operating range of the vibration proof lens 24c are set by the controller 240. The control target value limiter 220 has a control target value to be input in advance. The control target value is limited so as not to exceed the set operation range.

  The limit value of the operating range of the image stabilizing lens 24c is a position that is a predetermined amount inside the limit value (mechanical limit) with which the camera shake correction mechanism 201 comes into mechanical contact.

  The control target value output from the control target value limiter 220 is added to the positive input of the subtractor 222. A lens position signal indicating the current position of the image stabilizing lens 24c is added to the negative input of the subtractor 222. The subtracter 222 obtains a difference between the control target value and the lens position signal (current position). The difference is output as the operation amount of the image stabilizing lens 24c.

  The current position of the anti-vibration lens 24c is detected by the hall element 340. That is, the Hall element 340 outputs a detection signal (voltage signal) corresponding to the lens position of the image stabilizing lens 24 c and outputs this detection signal to the AD converter 226 via the amplifier 224. The AD converter 226 converts the input analog signal indicating the lens position into a digital signal, and outputs this to the subtractor 222 as a lens position signal indicating the current position of the image stabilizing lens 24c.

  The operation amount output from the subtracter 222 is phase-compensated by the phase compensation circuit 228 and then added to the motor driver 230. The motor driver 230 generates a pulse width modulated (PWM) drive signal corresponding to the input operation amount, and outputs this drive signal to the coil 322 (voice coil motor (VCM)) shown in FIG.

  As a result, the image stabilization lens 24c is driven in the X direction by a movement amount corresponding to the operation amount, and is controlled so as not to cause image blur due to camera shake in the X direction of the photographing apparatus. Note that, in the same way as camera shake in the X direction, camera shake in the Y direction is also corrected.

  The controller 240 controls the integration circuit 212, the integration limiter 214, and the control target value limiter 220. The controller 240 inputs the integration result (angle signal) from the integration circuit 212, and the lens position signal of the image stabilization lens 24c from the AD converter 226. , A signal indicating an upper limit value and a lower limit value indicating the operation range is input from the operation range setting unit 242, and a signal regarding the operation state of the image capturing apparatus 1000 (shooting operation, camera shake ON / OFF) is input from the CPU 10 (see FIG. 10). OFF mode signal).

  The operation range setting unit 242 sets each limit value indicating the upper limit value and the lower limit value of the operation range of the image stabilization lens 24c, and the controller 240 sets the limit value of the operation range set here to the control target value limiter 220. Set. Note that the limit value of the operation range set in the control target value limiter 220 may be set as a fixed value in advance, regardless of a command from the controller 240.

  When the controller 240 receives a signal indicating the camera shake correction off mode from the CPU 10, the controller 240 resets the integration value (angle) of the integration circuit 212 to 0 and stops the integration operation in the integration circuit 212 (or integrates 0). Let Thereby, when the center position of the operation range of the image stabilization lens 24c is set to 0, the control target value is 0, and the image stabilization lens 24c is stopped at the center position of the operation range.

  On the other hand, when the controller 240 receives a signal indicating the camera shake correction on mode from the CPU 10, the controller 240 enables the integration operation in the integration circuit 212. Further, the CPU 10 outputs to the controller 240 signals of a switch S1 that is turned on when the two-stage stroke is half-pressed and a switch S2 that is turned on when the stroke is fully pressed.

  The controller 240 enables the integration operation in the integration circuit 212 in the camera shake correction on mode, but in a period other than the ON state of the switch S1 and the ON state of the switch S2, the controller 240 is set to a value that slightly decreases the integration result (angle). The image stabilization lens 24c is gradually returned to the optical center. As a result, it is possible to avoid the fact that the image stabilization accuracy is lowered but the image stabilization operation cannot be performed. On the other hand, during the period in which the switch S1 is ON or the switch S2 is ON, the processing for correcting the integration result (angle) is not performed, and the image stabilization accuracy in this period is increased.

  Further, the controller 240 sets the upper limit value and the lower limit value of the integration limiter 214 based on the current deflection angle calculated by the integration circuit 212 and the current lens position of the image stabilization lens 24c detected by the Hall element 340 or the like. Change each limit value. Details of the control for changing the limit value of the integration limiter 214 will be described later.

<Image stabilization method>
FIG. 21 is a conceptual diagram showing a first mode of a camera shake correction method.

  FIG. 21 shows an example of the moving position of the image stabilization lens 24c that changes with time. It shows about the case.

  In FIG. 21, + A indicates the upper limit value of the mechanical limit of the image stabilization lens 24c, + B indicates the upper limit value of the operation range inside the mechanical limit, and + C temporarily limits the operation of the image stabilization lens 24c. The upper limit value of the limit range is shown. Although not shown, lower limit values (-B, -C) that define the operation range and the limit range are set at positions symmetrical to these upper limit values.

  If a shake in one direction close to a panning operation, a tilting operation, or the like is detected as a camera shake of the image capturing apparatus 1000, the image stabilization lens 24c is decremented over time in order to prevent image shake due to this shake. It is moved in the direction (in the plus direction from the center of the operating range of the image stabilizing lens 24c in FIG. 21). Note that since the panning operation is a camera operation for chasing a moving subject, the shooting conditions of the camera such as the focal length and the subject distance may be considered in the panning determination.

  When the position of the image stabilizing lens 24c reaches the upper limit value (+ C) of the limit range, the movement of the image stabilizing lens 24c is limited so as not to exceed the upper limit value (+ C). If a certain condition is satisfied in a state where the movement of the image stabilizing lens 24c is restricted by the restriction range, the restriction is released.

  Here, as a constant condition, when the shake in one direction is continued for a predetermined time, the position where the anti-vibration lens 24c is to be moved exceeds the limit range for a predetermined time continuously, the anti-vibration lens 24c is moved. When the power position exceeds the limit range by a predetermined threshold or more, the average value of the position to which the image stabilizing lens 24c should move for the latest fixed period may exceed the limit range.

  If it is determined that a certain condition is satisfied at time t1, the upper limit value C is changed so that the initially set limit range is expanded. In the first aspect, the upper limit value C of the limit range is changed to the same upper limit value (+ C ′) as the upper limit value (+ B) of the operation range. As a result, the anti-vibration lens 24c whose movement has been restricted becomes operable, and when the shake in one direction close to the panning operation or the like continues, the anti-vibration lens 24c is prevented in order to prevent image blur due to the shake. Moves in one direction again.

  Thereafter, at time t2, when the shake in one direction close to the panning operation or the like is finished and the camera shake is detected, the image stabilizing lens 24c is vibrated to prevent the image shake caused by the camera shake.

  Here, in the same situation as described above, when the restriction range is not provided, the vibration-proof lens 24c moves as indicated by the alternate long and short dash line, and reaches the upper limit (+ B) of the operation range at time t2. . Therefore, there is a problem that even if the shake in one direction close to the panning operation or the like ends at time t2, and the camera shake is detected, the vibration-proof lens 24c is limited to the operation range and cannot be vibrated properly.

  Further, when the limit range is provided, the vibration-proof lens 24c can be vibrated at a position close to the optical center having high optical performance by a distance L in FIG. There are advantages you can do.

  On the other hand, after the upper limit value (+ C) of the limit range is changed to the upper limit value (+ C ′), the control target value or the position of the image stabilizing lens 24c falls within the initially set limit range (limit value ± C) and is constant. When the above condition is satisfied, the upper limit value (+ C ′) of the changed limit range is returned to the upper limit value (+ C) of the initially set limit range. For example, when the current control target value is sufficiently inward of the initially set upper limit value (+ C) (a position where proper camera shake correction is possible), the changed upper limit value (+ C) Return ') to the upper limit (+ C) of the initially set limit range.

  As the current limit target value, an average value of the latest limit target values within a certain period may be used.

  In the example shown in FIG. 21, a case has been described in which one-way shake close to a panning operation or the like is completed at time t2, and image blur due to camera shake is prevented from time t2. Needless to say, when (+ C) is changed to the same upper limit value (+ C ′) as the upper limit value (+ B) of the operation range, the vibration-proof lens 24c can be moved to the upper limit value (+ C ′). Furthermore, the time until the vibration-proof lens 24c finally reaches the upper limit value (+ C ′) that is the same as the upper limit value (+ B) of the operation range is longer than that in the case where no limit range is provided. Therefore, it is possible to extend the time during which the camera shake correction can be appropriately performed.

  FIG. 22 is a flowchart showing camera shake correction processing in the first embodiment of the camera shake correction method according to the present invention.

  When the image capturing apparatus 1000 is switched to the camera shake correction on mode, an angle (shake angle) due to camera shake of the image capturing apparatus 1000 is detected by the angular velocity sensor 250, the integration circuit 212, and the like shown in FIG. 20 (step S110). Based on the detected shake of the photographing apparatus 1000, a control target value for driving the image stabilizing lens 24c is calculated via the camera shake correction mechanism 201 (step S112).

  Subsequently, it is determined whether or not the control target value calculated in step S112 is within the limit range (step S114). The limit range is changed to a limit range (± C ′) corresponding to the limit range (± B) initially set by the limit value (± C) and the limit value (± B) of the operation range as shown in FIG. There is a limited range.

  If the control target value is within the limit range, it is determined whether or not the limit range has been changed from the initially set limit range (step S116). When the limit range is not changed (in the case of the initially set limit range), the image stabilization lens 24c is driven via the camera shake correction mechanism based on the control target value, thereby correcting the image blur (step). S118).

  On the other hand, if it is determined in step S114 that the control target value has exceeded the limit range, the process proceeds to step S120. In step S120, the control target value is limited so that the control target value falls within the limit range.

  Here, the setting of the limit range (setting of the upper limit value and the lower limit value of the limit range) is performed by setting the limit value of the integral limiter 214 shown in FIG. That is, the control target value corresponds to the shake angle of the image capturing apparatus 1000, and the limit range for limiting the movement range of the image stabilization lens 24c can be set by the angle range. In the process of step S120, the integration limiter 214 limits the integration result (deflection angle), and thereafter limits the control target value converted from the deflection angle.

  Subsequently, it is determined whether or not a certain condition is detected in a state where the control target value is limited (step S122). For example, when a case where a one-way shake close to a panning operation or the like continues for a predetermined time is detected, and a certain condition is detected, the process proceeds to step S124. Transition.

  In step S124, the initially set limit range (limit value ± C) shown in FIG. 21 is changed to the same limit range (limit value ± C ′) as the operation range (limit value ± B). This limit range is also changed by setting the limit value of the integral limiter 214 shown in FIG. The limit values of the integration limiter 214 are set by commands from the controller 240.

  On the other hand, if it is determined in step S116 that the limit range has been changed from the initially set range, the process proceeds to step S126. In step S126, it is determined whether or not a condition for returning the changed limit range (limit value ± C ') to the limit range before the change (limit value ± C) is satisfied. For example, if the current control target value is well inside the limit value of the initially set limit range (position where proper camera shake correction is possible), the current control target value is set to the default limit A case where the state in the range continues for a certain time is determined.

  When it is determined in step S126 that the condition for returning the limit range (limit value ± C ′) to the initially set limit range (limit value ± C) is established, the process proceeds to step S128, where The limit range (limit value ± C ′) is returned to the initially set limit range (limit value ± C).

  The conditions for changing (and returning) the restriction range in the first aspect are not limited to this embodiment.

  FIG. 23 is a conceptual diagram showing a second aspect of the camera shake correction method.

  FIG. 23 shows an example of the moving position of the image stabilizing lens 24c that changes with time as in FIG. 21, and shows the case where the image stabilizing lens 24c moves from the center of the operating range to one side. .

  In FIG. 23, when a shake in one direction close to a panning operation, a tilting operation, or the like is detected as a camera shake of the photographing apparatus 1000, the anti-vibration lens 24c has elapsed over time in order to prevent image shake due to this shake. At the same time, it is moved in one direction (in the plus direction from the center of the operating range of the image stabilizing lens 24c in FIG. 23).

  When the position of the image stabilizing lens 24c reaches the upper limit value (+ C) of the limit range, the movement of the image stabilizing lens 24c is limited so as not to exceed the upper limit value (+ C). In a state where the movement of the anti-vibration lens 24c is restricted by the restriction range, a shake in one direction close to a panning operation, a tilting operation, or the like is detected (time t1), and then the shake detection in one direction ends (time t2). ), The limit range (limit value ± C) is changed to an expanded limit range (limit value ± C ′), so that appropriate camera shake correction can be performed immediately from time t2.

  In other words, if the initially set limit range is maintained at time t2, there is a problem that only the shake correction in the negative direction can be performed due to the limit of the limit range (upper limit value + C). Further, the control target value is generated so as to gradually return to the optical center of the optical system, whereby the vibration center of the image stabilizing lens 24c is controlled to be returned to the optical center, but the image stabilizing lens 24c is controlled to the limit end. It takes time to return to the optical center to some extent, and camera shake correction during this time cannot be performed properly. In particular, if an appropriate camera shake correction is not performed when the release button of the operation unit 12 is pressed, a blurred image is captured.

  Therefore, in the second mode, the movement range of the image stabilizing lens 24c is limited by the initially set limit range (limit value ± C). However, when the end of the panning operation or the like is detected as described above, it is immediately appropriate. The initially set limit range (limit value ± C) is expanded to the limit range (limit ± C ′) so that the camera shake can be corrected. If the anti-vibration lens 24c is located near the end of the limit range (limit value ± C) when the release button is pressed (when the switch S1 is ON or the switch S2 is ON), the limit range is set. (Limit value ± C) may be expanded to a limit range (limit value ± C ′).

  Further, by restricting the movement range of the image stabilizing lens 24c by the initially set range (limit value ± C), the image stabilizing lens 24c can be vibrated at a position close to the optical center having high optical performance. There are advantages.

  On the other hand, in the same situation as described above, when the restriction range is not provided, the vibration-proof lens 24c moves as indicated by the alternate long and short dash line, and reaches the upper limit (+ B) of the operation range at time t2. Therefore, there is a problem that even if the shake in one direction close to the panning operation or the like ends at time t2 and the camera shake is detected, the vibration-proof lens 24c is limited to the operation range and cannot be vibrated properly. Further, when the restriction range is not provided, there is a problem that the vibration-proof lens 24c operates near the limit of the operation range away from the optical center having low optical performance.

  Note that the camera shake correction processing in the second mode is performed in the same manner as in the first mode (see the flowchart of FIG. 22). However, the 1st mode and the 2nd mode differ in the conditions which change a restriction range, and the restriction range which changes.

  FIG. 24 is a conceptual diagram showing a third aspect of the camera shake correction method.

  FIG. 24 shows an example of the moving position of the image stabilizing lens 24c that changes with time as in FIG. 21, and shows the case where the image stabilizing lens 24c moves from the center of the operating range to one side. .

  In FIG. 24, when a shake in one direction close to a panning operation, a tilting operation, or the like is detected as a camera shake of the photographing apparatus 1000, the anti-vibration lens 24c has elapsed over time to prevent image shake due to this shake. At the same time, it is moved in one direction (in the plus direction from the center of the operating range of the image stabilizing lens 24c in FIG. 24).

  When the position of the image stabilizing lens 24c reaches the upper limit value (+ C) of the restriction range, the movement of the image stabilizing lens 24c is restricted so as not to exceed the upper limit value (+ C), and within the initially set restriction range. A certain enlargement value is added to the upper limit value (+ C), and the limit range having the added upper limit value (+ C ′) is set as the next limit range. That is, when the current limit target value exceeds the current control range, the next control range is expanded by a certain value. As the current limit target value, an average value of the latest limit target values within a certain period may be used.

  As a result, when a shake in one direction close to a panning operation or the like is continuously detected, the limit range (upper limit value + C ′) is gradually expanded.

  As shown in FIG. 24, when the restriction range is not provided, the anti-vibration lens 24c moves as indicated by the alternate long and short dash line, and reaches the upper limit value (+ B) of the operation range at time t2. By setting the limit range that gradually expands as in the third aspect, the vibration-proof lens 24c is positioned near the optical center with higher optical performance without reaching the limit of the operation range even at time t2. It can be vibrated with.

  In FIG. 24, the slope of the limit range that is gradually expanded between time t1 and time t2 is determined by the size of the added value to be added. If the enlargement value is too large, the vibration-proof lens 24c is likely to move near the limit of the operating range. On the other hand, if the enlargement value is too small, camera shake correction between time t1 and time t2 is limited. Since it is greatly received, the accuracy of camera shake correction is reduced. Therefore, the size of the enlargement value needs to be set to an appropriate value in view of these circumstances.

  On the other hand, when the control target value or the current position of the anti-vibration lens 24c is smaller than the upper limit value (+ C ′) by a certain value (for example, the enlargement value) or more than the upper limit value (+ C ′) of the current limit range Is subtracted from the upper limit value (+ C ′) by a certain reduced value (which may be the same as or different from the enlarged value), and this is used as the next limit range. As a result, the changed limit range can be gradually returned to the initially set limit range.

  In the example shown in FIG. 24, the case has been described in which the shake in one direction close to the panning operation or the like is completed at time t2, and the image shake due to the camera shake is prevented from this time t2. Since (+ C) can be finally changed to the upper limit value (+ B) of the operating range, it goes without saying that the image stabilization lens 24c can be moved to the upper limit value (+ B) of the operating range. Furthermore, the time until the vibration-proof lens 24c finally reaches the upper limit value (+ B) of the operation range is longer than that in the case where the limit range is not provided, and the camera shake correction is appropriately performed by the length. You can extend the time you spend.

  FIG. 25 is a flowchart showing camera shake correction processing in the third mode of the camera shake correction method. Note that the same step numbers are assigned to portions common to the flowchart shown in FIG. 22, and a detailed description thereof is omitted.

  The camera shake correction process of the third mode shown in FIG. 25 is different in that the processes of steps S130 and S132 are performed instead of the processes of steps S122 and S124 and steps S126 and S128 shown in FIG. .

  That is, in the first aspect, when the control target value exceeds the initially set limit range and a certain condition (such as a one-way shake close to panning operation) is detected, the initially set limit range is expanded. However, in the third mode, as shown in step S130, the detection of a certain condition is not performed, the limit value of the current limit range is expanded by a predetermined amount (a constant expansion value), This is set to the next limit range.

  Similarly, when returning the limit range, as shown in step S132, the limit value of the current limit range is reduced by a predetermined amount (a constant reduction value) without detecting the condition for returning the limit range, This is set to the next limit range.

  In the third aspect, when the current control target value exceeds the current limit range, the current control target value is increased by a certain expansion value, and when the current control target value falls below the current limit range, the constant value is constant. Although the reduction value is reduced and returned to the initially set limit range, in the modification of the third aspect, when the current control target value exceeds the limit value of the current limit range, the excess amount (A difference between the current control target value and the limit value) is calculated, a value corresponding to this difference is added to the current limit value, and this added value is set as the next limit value.

  Similarly, if the current control target value falls below the limit value of the current limit range, the amount below that (the difference between the current control target value and the limit value) is calculated, and the value corresponding to this difference Is subtracted from the current limit value, and this subtracted value is used as the next limit value.

  As the current control target value (corresponding to the shake), the average value of the shake detected within the latest fixed period may be used. Further, the value corresponding to the calculated difference can be, for example, a value obtained by multiplying the difference by a value smaller than 1.

  The camera shake correction process in the modified example of the third aspect is performed in the same manner as in the third aspect (see the flowchart of FIG. 25). However, the difference is that a value corresponding to the difference between the current control target value and the limit value is used instead of the predetermined amount in steps S130 and S132.

  FIG. 26 is a conceptual diagram showing a fourth aspect of the camera shake correction method.

  The fourth embodiment shown in FIG. 26 is a combination of the second mode shown in FIG. 23 and the third mode shown in FIG.

  That is, as a camera shake of the photographing apparatus 1000, a shake in one direction similar to a panning operation or a tilting operation is detected, and in order to prevent image shake due to this shake, the image stabilization lens 24c is moved in one direction over time. Move. When the position of the image stabilizing lens 24c reaches the upper limit value (+ C) of the limit range at time t1, the limit range is gradually expanded thereafter. The control of the above limit range is the same as that of the third embodiment.

  On the other hand, at the end of one-way shake detection such as panning operation or when the release button of the operation unit 12 is pressed (time t2), the current limit range is set to a fixed amount ΔX (in FIG. 26, plus direction camera shake correction). Is increased by a value that can also be properly performed), so that appropriate camera shake correction can be performed immediately from time t2. The control of this limit range is the same as in the second embodiment.

  In the example shown in FIG. 26, the case where the shake in one direction close to the panning operation or the like ends at time t2 and the image shake due to the camera shake is prevented from time t2 has been described. Since (+ C) can be finally changed to the upper limit value (+ B) of the operating range, it goes without saying that the image stabilization lens 24c can be moved to the upper limit value (+ B) of the operating range. Furthermore, the time until the vibration-proof lens 24c finally reaches the upper limit value (+ B) of the operation range is longer than that in the case where the limit range is not provided, and the camera shake correction is appropriately performed by the length. You can extend the time you spend.

  In the first to fourth aspects of the camera shake correction method, the case where the focal length does not change has been described as an example in order to explain the present invention in a simplified manner. However, the case where the focal length is changed will be described below. .

  In FIG. 20, a control target value calculation circuit 218 calculates a control target value based on an angle signal indicating a deflection angle input from the phase compensation circuit 216 and current focal length information of the imaging optical system 24 input from the CPU 10. To do.

  That is, the control target value calculation circuit 218 multiplies the input angle signal by the mechanical coefficient γ read from the memory (not shown) based on the focal length information, and the displacement of the image stabilizing lens 24c for correcting the shake. The amount (control target value) is calculated.

  The mechanical coefficient γ is a value corresponding to the focal length of the photographing optical system 24. The larger the focal length, the larger the mechanical coefficient γ. Actually, the mechanical coefficient γ is determined in consideration of the conversion efficiency of the coils 322 and 323 in addition to the focal length. As the mechanical coefficient γ at each focal length, for example, a numerical value shown in FIG. 27 is used. With this mechanical coefficient γ, even when the camera shake is the same, the control target value is calculated so that the movement amount of the image stabilizing lens 24c is larger when the focal distance is long than when the focal distance is short.

  Next, the limit angle of the integration limiter 214 that is initially set by the controller 240 and the limit angle that is changed will be described.

  Now, in a state where the zoom lens 24z of the photographing optical system 24 is located at the telephoto end (tele end), the anti-vibration lens 24c is set to the limit value (± B of the operating range of the anti-vibration lens 24c shown in FIG. ), The controller 240 initially sets the maximum angle (± β) in the integration limiter 214, assuming that the maximum angle at which image blur can be corrected is ± β. This initially set limit angle is a constant value regardless of the focal length of the photographic optical system 24.

  In this way, by setting a fixed limit angle regardless of the focal length of the photographic optical system 24, a limit range that is initially set based on the product of the limit angle and the mechanical coefficient γ corresponding to the focal length. As a result, the limit value (± C) is determined by the ratio between the maximum focal length (or the corresponding mechanical coefficient γ) and the current focal length (or the corresponding mechanical coefficient γ) and the operating range. This value is obtained by multiplying the limit value (± B).

  Incidentally, the limit range shown in FIG. 21 and the like is a range that temporarily limits the movement of the image stabilizing lens 24c, but when the limit angle that is initially set in the integral limiter 214 is set to the above angle (± β). The limit value (± C) of the limit range when the photographing lens 11 is at the telephoto end coincides with the limit value (± B) of the movable range of the vibration-proof lens 24c and cannot be enlarged any further.

  Therefore, when the zoom sequence 24z of the photographing optical system 24 is a focal length other than the tele end, the limit range can be expanded.

  In the present invention, the initially set limit range can be changed. However, the lower the zoom magnification of the photographing optical system 24, the wider the changeable range.

  That is, the controller 240 receives the current focal length information of the photographing optical system 24 from the CPU 10, and changes the initial limit angle of the integration limiter 214 to the current focal length of the photographing lens 11. Change accordingly.

  For example, when the zoom magnification of the photographing optical system 24 is 6 times (the ratio of the focal length at the tele end to the focal length at the wide end is 6), the limit range (± C) when the photographing optical system 24 is at the wide end is The operating range is about one-sixth of the operating range, and the initially set limiting range can be expanded to about six.

  Therefore, when the limit angle (± β) that is initially set in the integral limiter 214 is, for example, ± 0.5 °, when the photographing lens 11 is at the wide end, the limit angle is 6 times (± 3 °). Can be changed up to.

  As described above, in the description of the first to fourth modes of camera shake correction using FIGS. 21, 23, 24, and 26, the “movement amount” of the image stabilizing lens 24c is based on the operation center of the image stabilizing lens 24c. The movement amount in the forward (+) direction or the reverse (−) direction has been described. On the other hand, in the description of the fourth to sixth embodiments of the autofocus using FIGS. 6 and 13, “shake amount” and “shake correction amount” are absolute amounts of movement from the operation center of the image stabilizing lens 24c. Described as a value. That is, the term “limit value” corresponds to the absolute value of “operating range upper limit value” and “operating range lower limit value”, and the term “limit value” refers to “limit range upper limit value” and “limit range lower limit value”. Corresponds to the absolute value of "."

  The correction limiting function is not particularly limited to the mode described with reference to FIGS. An “operation range” indicated by the “limit value” (which is the maximum movable range of the anti-vibration lens 24c) and a “restrict range” indicated by the “limit value” (the movable range of the limited anti-vibration lens 24c). ) May be determined as appropriate.

  Further, the case where the image stabilization is corrected by moving the image stabilizing lens 24c has been described. However, the present invention is not limited to this. For example, the image blur is corrected by moving an image sensor such as a CCD or CMOS in a direction orthogonal to the optical axis. You may do it. The “limit value” and “limit value” of the camera shake correction amount are appropriately determined in each aspect.

  The present invention is not particularly limited when applied to a digital camera that records an image as digital data, and may of course be applied to a so-called silver salt camera that records an image on a film. It can be applied to any mobile terminal with a camera such as a mobile phone.

  Note that the present invention is not limited to the examples described in the present specification and the examples illustrated in the drawings, and may be implemented in combination as appropriate, and various designs may be made without departing from the gist of the present invention. Of course, changes and improvements may be made.

1 is a block diagram illustrating a hardware configuration example of a photographing apparatus according to first to third embodiments. 1 is a block diagram illustrating a main part of an example of an imaging apparatus according to a first embodiment. Schematic flowchart showing the flow of an example of autofocus processing in the first embodiment The block diagram which shows the principal part of an example of the imaging device which concerns on 2nd Embodiment. Schematic flowchart showing the flow of an example of autofocus processing in the second embodiment Explanatory drawing used for explanation of an example of weighting in the second embodiment Explanatory drawing used to describe an example of camera shake The block diagram which shows the principal part of an example of the imaging device which concerns on 3rd Embodiment. Schematic flowchart showing a flow of an example of autofocus processing in the third embodiment The block diagram which shows the hardware structural example of the imaging device which concerns on 4th Embodiment and 5th Embodiment The block diagram which shows the principal part of an example of the imaging device which concerns on 4th Embodiment. Schematic flow showing an exemplary flow of autofocus processing in the fourth embodiment Explanatory drawing used for explanation of an example of weighting in the fourth embodiment The block diagram which shows the principal part of an example of the imaging device which concerns on 5th Embodiment. Schematic flow showing an exemplary flow of autofocus processing in the fifth embodiment Sectional view showing an outline of a structural example of the photographic optical system An exploded perspective view of an example of a camera shake correction mechanism Front view of an example of image stabilization mechanism Cross-sectional view of the main part of an example of the image stabilization mechanism The block diagram which shows the internal structure of an example of a camera-shake correction control part Conceptual diagram showing a first aspect of camera shake correction Flowchart showing the flow of processing in the first mode of camera shake correction Conceptual diagram showing a second aspect of camera shake correction Conceptual diagram showing a third aspect of camera shake correction Flowchart showing the flow of processing in the third mode of camera shake correction Conceptual diagram showing a fourth aspect of camera shake correction Chart showing mechanical coefficient γ at each focal length for calculating lens displacement

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Camera, 10 ... CPU, 30 ... Image pick-up element, 24 ... Imaging optical system, 24c ... Anti-vibration lens, 24f ... Focus lens, 66 ... External light AF sensor (ranging sensor), 68 ... Camera shake amount detection part, 102 ... 1st focus position acquisition part, 106 ... AF evaluation value calculation part, 108 ... 2nd focus position acquisition part, 110 ... Selection part (focus position determination means), 112 ... AF control part (focus lens movement means) 120, 140 ... weighting control unit (focus position determination means), 130 ... on / off control unit, 132, 152 ... data control unit (focus position determination means), 200 ... camera shake correction unit, 201 ... camera shake correction mechanism 202 Shake correction control unit

Claims (20)

A photographing optical system having a focus lens;
A distance measuring sensor that measures the distance to the subject;
First focus position acquisition means for acquiring a first focus position of the focus lens corresponding to a measurement distance of the distance measuring sensor;
A light receiving element that receives light from the subject via the photographing optical system;
Second focus position acquisition means for performing focus detection based on an output signal of the light receiving element to acquire a second focus position of the focus lens;
Camera shake amount detecting means for detecting the amount of camera shake;
A focus position determining unit that obtains a third focus position by weighting the first focus position and the second focus position based on a camera shake amount detected by the camera shake amount detection unit;
Focus lens moving means for moving the focus lens to the third in-focus position;
An autofocus device characterized by comprising:   The in-focus position determining means determines the third in-focus position by selecting one of the first in-focus position and the second in-focus position as the third in-focus position. The autofocus device according to claim 1.   The in-focus position determining means continuously changes the weights for the first in-focus position and the second in-focus position with respect to the amount of camera shake detected by the hand-shake amount detecting means. The autofocus device according to claim 1, wherein   The focus position determination unit increases the weight of the first focus position corresponding to the measurement distance of the distance measurement sensor as the amount of camera shake increases. Autofocus device. A photographing optical system having a focus lens;
A distance measuring sensor that measures the distance to the subject;
First focus position acquisition means for acquiring a first focus position of the focus lens corresponding to a measurement distance of the distance measuring sensor;
A light receiving element that receives light from the subject via the photographing optical system;
Second focus position acquisition means for performing focus detection based on an output signal of the light receiving element to acquire a second focus position of the focus lens;
Camera shake amount detecting means for detecting the amount of camera shake;
On / off control means for switching on / off of the distance measuring operation of the distance measuring sensor based on the amount of camera shake detected by the camera shake amount detecting means;
When the ranging operation is in the on state, the focus lens position is determined using at least the first focusing position, while when the ranging operation is in the off state, the second focusing is performed. Focusing position determining means for determining the position of the focus lens using only the position;
A focus lens moving means for moving the focus lens to a position determined by the in-focus position determining means;
An autofocus device characterized by comprising: The on / off control means switches on / off of the focus detection operation by the second focus position acquisition means based on the camera shake amount detected by the camera shake amount detection means,
6. The auto according to claim 5, wherein the focus position determining unit determines the position of the focus lens using only the first focus position when the focus detection operation is in an off state. Focus device. Comprising an image stabilization unit for performing image stabilization based on the amount of image stabilization;
The in-focus position determining unit weights the first in-focus position and the second in-focus position when the amount of camera shake exceeds a limit value or a limit value of camera shake correction in the image stabilization unit. The autofocus device according to claim 1, wherein the third in-focus position is obtained. Comprising an image stabilization unit for performing image stabilization based on the amount of image stabilization;
The in-focus position determining unit is configured to determine the first in-focus position corresponding to the measurement distance of the distance measuring sensor when the amount of camera shake exceeds a limit value or a limit value of camera shake correction in the camera shake correction unit. The autofocus device according to claim 2, wherein the autofocus device is selected. Comprising an image stabilization unit for performing image stabilization based on the amount of image stabilization;
The on / off control means sets the distance measurement operation of the distance measurement sensor to an on state when the amount of camera shake exceeds a threshold value indicating a limit value or a limit value of camera shake correction in the camera shake correction means, The autofocus device according to claim 5 or 6, wherein when the amount of camera shake does not exceed the threshold value, the distance measuring operation of the distance measuring sensor is set to an off state. Comprising an image stabilization unit for performing image stabilization based on the amount of image stabilization;
The camera shake correction means has a correction limiting function that limits camera shake correction and prevents overcorrection,
The in-focus position determination unit is configured to increase the difference between the camera shake amount detected by the camera shake amount detection unit and the camera shake correction amount by the camera shake correction unit during the operation of the correction restriction function. 5. The autofocus device according to claim 1, wherein a weight of the first in-focus position corresponding to a measurement distance is increased.   The auto according to any one of claims 1, 3, 4, 7, and 10, further comprising display means for displaying that weighting is performed using the first in-focus position. Focus device.   9. The autofocus device according to claim 2, further comprising display means for displaying which one of the first focus position and the second focus position is selected. .   10. The autofocus device according to claim 5, further comprising display means for displaying whether or not the distance measuring operation is in an on state.   The auto according to any one of claims 1 to 13, wherein the first focus position acquisition means acquires the first focus position by either triangulation or propagation time detection. Focus device.   The autofocus according to any one of claims 1 to 14, wherein the second focus position acquisition unit acquires the second focus position by either contrast detection or phase detection. apparatus.   A camera comprising the autofocus device according to any one of claims 1 to 15. A photographing optical system having a focus lens; a light receiving element that receives light from the subject via the photographing optical system; a distance measuring sensor that measures a distance to the subject; and a camera shake amount detecting unit that detects a camera shake amount. An autofocus method to be used,
Measuring a distance to a subject by the distance measuring sensor, and obtaining a first in-focus position of the focus lens corresponding to the measured distance;
Receiving light from a subject via the photographing optical system by the light receiving element, performing focus detection based on an output signal of the light receiving element, and obtaining a second in-focus position of the focus lens;
Detecting the amount of camera shake;
An in-focus position determining step for obtaining a third in-focus position by weighting the first in-focus position and the second in-focus position based on the detected amount of camera shake;
Moving the focus lens to the third in-focus position;
Including an autofocus method.   In the in-focus position determining step, the third in-focus position is determined by selecting either the first in-focus position or the second in-focus position as the third in-focus position. The autofocus method according to claim 17.   18. In the focus position determination step, weights for the first focus position and the second focus position are continuously changed with respect to the detected amount of camera shake. The autofocus method described in 1. A photographing optical system having a focus lens; a light receiving element that receives light from the subject via the photographing optical system; a distance measuring sensor that measures a distance to the subject; and a camera shake amount detecting unit that detects a camera shake amount. An autofocus method to be used,
Detecting the amount of camera shake;
Switching on / off of the distance measuring operation of the distance sensor based on the detected amount of camera shake;
Obtaining a first in-focus position of the focus lens corresponding to a measurement distance of the distance measurement sensor when the distance measurement operation is in an on state;
Obtaining a second focus position of the focus lens by performing focus detection based on an output signal of the light receiving element when the focus detection operation is in an on state;
When the ranging operation is in the on state, the focus lens position is determined using at least the first focusing position, while when the ranging operation is in the off state, the second focusing is performed. Determining the position of the focus lens using only the position;
Moving the focus lens to the determined position;
Including an autofocus method.

Images