WO2015064279A1 - Image capture device and control method therefor - Google Patents

Image capture device and control method therefor Download PDF

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Publication number
WO2015064279A1
WO2015064279A1 PCT/JP2014/076079 JP2014076079W WO2015064279A1 WO 2015064279 A1 WO2015064279 A1 WO 2015064279A1 JP 2014076079 W JP2014076079 W JP 2014076079W WO 2015064279 A1 WO2015064279 A1 WO 2015064279A1
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WO
WIPO (PCT)
Prior art keywords
frequency
drive signal
low
frequency drive
driving
Prior art date
Application number
PCT/JP2014/076079
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French (fr)
Japanese (ja)
Inventor
篤志 松谷
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リコーイメージング株式会社
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Application filed by リコーイメージング株式会社 filed Critical リコーイメージング株式会社
Priority to JP2015544883A priority Critical patent/JP6406264B2/en
Publication of WO2015064279A1 publication Critical patent/WO2015064279A1/en

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B5/00—Adjustment of optical system relative to image or object surface other than for focusing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
    • H04N25/10—Circuitry of solid-state image sensors [SSIS]; Control thereof for transforming different wavelengths into image signals
    • H04N25/11—Arrangement of colour filter arrays [CFA]; Filter mosaics
    • H04N25/13—Arrangement of colour filter arrays [CFA]; Filter mosaics characterised by the spectral characteristics of the filter elements
    • H04N25/134—Arrangement of colour filter arrays [CFA]; Filter mosaics characterised by the spectral characteristics of the filter elements based on three different wavelength filter elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B27/00—Optical systems or apparatus not provided for by any of the groups G02B1/00 - G02B26/00, G02B30/00
    • G02B27/64—Imaging systems using optical elements for stabilisation of the lateral and angular position of the image
    • G02B27/646—Imaging systems using optical elements for stabilisation of the lateral and angular position of the image compensating for small deviations, e.g. due to vibration or shake
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/60—Control of cameras or camera modules
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/60—Control of cameras or camera modules
    • H04N23/68—Control of cameras or camera modules for stable pick-up of the scene, e.g. compensating for camera body vibrations
    • H04N23/681—Motion detection
    • H04N23/6812—Motion detection based on additional sensors, e.g. acceleration sensors
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N23/00—Cameras or camera modules comprising electronic image sensors; Control thereof
    • H04N23/60—Control of cameras or camera modules
    • H04N23/68—Control of cameras or camera modules for stable pick-up of the scene, e.g. compensating for camera body vibrations
    • H04N23/682—Vibration or motion blur correction
    • H04N23/685—Vibration or motion blur correction performed by mechanical compensation
    • H04N23/687—Vibration or motion blur correction performed by mechanical compensation by shifting the lens or sensor position
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B2205/00—Adjustment of optical system relative to image or object surface other than for focusing
    • G03B2205/0007—Movement of one or more optical elements for control of motion blur
    • G03B2205/0015—Movement of one or more optical elements for control of motion blur by displacing one or more optical elements normal to the optical axis

Definitions

  • the present invention relates to an imaging apparatus that obtains an optical low-pass filter effect by driving a moving member (shake correction member) in a direction different from the optical axis of an imaging optical system (for example, in a plane orthogonal to the optical axis), and a control method thereof. .
  • Patent Document 1 discloses a photographing apparatus that obtains an optical low-pass filter effect by driving (microvibration) a moving member (shake correction optical system) forming a part of a photographing optical system in a plane orthogonal to the optical axis. Has been.
  • Patent Document 1 does not disclose a specific method for controlling the moving member (shake correction optical system) with high accuracy by the pixel pitch width. As the image sensor continues to increase in pixels and the pixel pitch continues to decrease, it becomes difficult to control the moving member (blur correction optical system) within the pixel pitch width. On the other hand, when only a high-frequency drive signal including a minute high-frequency component is used to drive and control the moving member (shake correction optical system) with high accuracy, high-frequency noise is generated, which may cause discomfort to the user. .
  • Japanese Patent Laid-Open No. 2004-228561 reduces the vibration transmitted to the photographer during the control of camera shake correction by controlling the fluidizing operation when driving control is performed by reducing the frictional force using the fluidizing method.
  • an optical apparatus that prevents image blurring is disclosed.
  • Patent Document 2 merely changes the fluidizing control based on only two parameters, ie, the length of the exposure time and whether or not the exposure is in progress, and the drive control flexibility is extremely low.
  • JP 2002-354336 A Japanese Patent No. 3530643
  • the present invention has been made on the basis of the above problem awareness, and in the photographing apparatus and its control method for obtaining an optical low-pass filter effect by driving the moving member, the moving member is driven and controlled with high accuracy and flexibility. In addition, it is an object to prevent the user from feeling uncomfortable by generating high frequency noise.
  • An imaging apparatus of the present invention moves at least one of an image sensor that converts a subject image formed by an imaging optical system into an electrical pixel signal, an optical element that forms at least a part of the imaging optical system, and the image sensor.
  • the subject luminous flux is made incident on a plurality of pixels having different detection colors of the image sensor, and an optical low-pass filter effect is obtained.
  • the driving signal generating unit has a driving frequency lower than a predetermined critical frequency.
  • a low-frequency drive signal generating unit that generates a low-frequency drive signal, and a high-frequency drive that generates a high-frequency drive signal having a drive frequency higher than a predetermined critical frequency.
  • a second superposition synthesis unit that generates a superposition drive signal as the drive signal by superposing and synthesizing the high frequency drive signal generated by the high frequency drive signal generation unit on the superposition control target signal generated by the superposition synthesis unit; It is characterized by having.
  • An imaging apparatus includes an exposure time setting unit for setting an exposure time, and a driving frequency of the low frequency drive signal generated by the low frequency drive signal generation unit according to the exposure time set by the exposure time setting unit.
  • the imaging apparatus of the present invention includes an exposure time setting unit that sets an exposure time, and driving of a low frequency drive signal generated by the low frequency drive signal generation unit according to the exposure time set by the exposure time setting unit.
  • a first frequency determining unit that determines a frequency, and a driving frequency of the high-frequency driving signal generated by the high-frequency driving signal generating unit is determined according to the driving frequency of the low-frequency driving signal determined by the first frequency determining unit.
  • a second frequency determination unit is provided.
  • the drive frequency of the high frequency drive signal generated by the high frequency drive signal generator is preferably such that the gain of the closed loop characteristic of the controller is -12 dB or less.
  • the movement of the moving member due to the high-frequency drive signal generated by the high-frequency drive signal generation unit is relatively high when the movement of the moving member due to the low-frequency drive signal generated by the low-frequency drive signal generation unit is relatively large. Small is preferable.
  • the amplitude of the high frequency drive signal generated by the high frequency drive signal generator is changed according to the amplitude of the low frequency drive signal generated by the low frequency drive signal generator.
  • the photographing apparatus of the present invention further includes a shake detection unit that detects a shake of the body main body on which the image sensor is mounted, and the shake detection unit outputs the detected shake detection signal as the control target signal. Is preferred.
  • a method for controlling an imaging apparatus comprising: an image sensor that converts an object image formed by an imaging optical system into an electrical pixel signal; an optical element that forms at least a part of the imaging optical system; One of them is a moving member, and this moving member is driven in a direction different from the optical axis of the photographing optical system, so that the subject luminous flux is incident on a plurality of pixels having different detection colors of the image sensor, and an optical low-pass filter.
  • a drive mechanism for obtaining an effect and a drive signal generation step for generating a drive signal for driving the moving member via the drive mechanism, wherein the drive signal generation step includes: A low-frequency drive signal generating step for generating a low-frequency drive signal having a drive frequency lower than a predetermined critical frequency; and a drive higher than the predetermined critical frequency.
  • the superposition drive signal as the drive signal is generated by superposing and synthesizing the high frequency drive signal generated in the high frequency drive signal generation step on the superposition control target signal generated in the first superposition synthesis step.
  • a second superimposing and synthesizing step is used to generate a second superimposing and synthesizing step.
  • the method for controlling an imaging apparatus includes: an exposure time setting step for setting an exposure time; and a low frequency drive signal generated in the low frequency drive signal generation step in accordance with the exposure time set in the exposure time setting step.
  • a frequency determining step for determining a driving frequency, and a duty ratio determining step for determining a duty ratio of the high-frequency driving signal generated in the high-frequency driving signal generating step according to the driving frequency of the low-frequency driving signal determined in the frequency determining step It is preferable to further include
  • the control method of the photographing apparatus of the present invention includes an exposure time setting step for setting an exposure time, and a low frequency drive generated in the low frequency drive signal generation step according to the exposure time set in the exposure time setting step.
  • a first frequency determining step for determining a driving frequency of the signal, and driving of the high-frequency driving signal generated in the high-frequency driving signal generating step according to the driving frequency of the low-frequency driving signal determined in the first frequency determining step Preferably, the method further comprises a second frequency determination step for determining a frequency.
  • the drive frequency of the high-frequency drive signal generated in the high-frequency drive signal generation step is preferably such that the gain of the closed-loop characteristic of the controller is ⁇ 12 dB or less.
  • the movement of the moving member due to the high frequency drive signal generated in the high frequency drive signal generation step is relatively high when the movement of the moving member due to the low frequency drive signal generated in the low frequency drive signal generation step is relatively large. Small is preferable.
  • the amplitude of the high frequency drive signal generated in the high frequency drive signal generation step is changed according to the amplitude of the low frequency drive signal generated in the low frequency drive signal generation step.
  • the control method of the photographing apparatus of the present invention further includes a shake detection step of detecting a shake of the body body on which the image sensor is mounted, and in the shake detection step, the detected shake detection signal is used as the control target signal. It is preferable to output.
  • the moving member in an imaging device and a control method thereof that obtain an optical low-pass filter effect by driving a moving member, the moving member is driven and controlled with high accuracy and flexibility, and high-frequency noise is generated to the user. An unpleasant feeling can be prevented.
  • FIG. 1 is a block diagram illustrating a main configuration of a digital camera (photographing apparatus) according to a first embodiment of the present invention.
  • FIG. 3 is a block diagram illustrating a configuration of a main part of an image blur correction device (drive mechanism). It is a side view which shows the structure of an image shake correction apparatus (drive mechanism).
  • 4A and 4B are diagrams showing an operation for giving an optical low-pass filter effect by driving the image sensor so as to draw a predetermined locus
  • FIG. 4A is a diagram of the photographing optical system. When the image sensor is driven to draw a rotationally symmetric square locus centered on the optical axis, FIG.
  • FIG. 4B shows the image sensor being drawn so as to draw a rotationally symmetric circular locus centered on the optical axis of the imaging optical system.
  • driving is shown.
  • It is a functional block diagram which shows the structure of an image sensor drive circuit (drive signal generation part).
  • FIG. 7 shows the digital camera which concerns on 3rd Embodiment of this invention.
  • FIG. 9 shows the digital camera which concerns on 3rd Embodiment of this invention.
  • the digital camera 10 includes a body main body 20 and a photographic lens 30 that can be attached to and detached from the body main body 20 (lens exchangeable).
  • the photographic lens 30 includes, in order from the subject side (left side in FIG. 1) to the image plane side (right side in FIG. 1), a photographic lens group (photographic optical system, moving member, shake correction member) 31, and aperture ( Photographing optical system) 32.
  • the body main body 20 has a shutter (photographing optical system) 21 and an image sensor (moving member, shake correction member) 22 in order from the subject side (left side in FIG. 1) to the image plane side (right side in FIG. 1). And.
  • the body body 20 also includes a diaphragm / shutter drive circuit 23 that controls driving of the diaphragm 32 and the shutter 21 in a state where the body body 20 is attached to the photographing lens 30.
  • a subject image is formed on the light receiving surface of the image sensor 22 by the subject light flux that enters from the photographing lens group 31 and passes through the aperture 32 and the shutter 21.
  • the subject image formed on the light receiving surface of the image sensor 22 is converted into an electrical pixel signal by a large number of pixels arranged in a matrix, and is output to the DSP 40 as image data (still image data, moving image data).
  • the DSP 40 performs predetermined image processing on the image data input from the image sensor 22, displays it on the LCD 24, and stores it in the image memory 25.
  • the photographic lens group 31 is drawn so as to be composed of a single lens (optical element).
  • the actual photographic lens group 31 may be, for example, a fixed lens, a variable magnification lens that moves during magnification, It consists of a plurality of lenses (optical elements) such as a focusing lens that moves during focusing.
  • the image sensor 22 includes a plurality of packages, a solid-state image sensor chip housed in the package, and a lid member fixed to the package so as to hermetically protect the solid-state image sensor chip. It consists of the following components.
  • “to drive the image sensor (moving member, shake correction member) 22” means “at least one of the plurality of components of the image sensor (moving member, shake correction member) 22 through which the subject luminous flux passes. Means to drive the part.
  • the photographing lens 30 includes a communication memory 33 that stores various information such as resolving power (MTF) information of the photographing lens group 31 and aperture diameter (aperture value) information of the diaphragm 32.
  • various information stored in the communication memory 33 is read into the DSP 40.
  • the body main body 20 is connected to the DSP 40 and includes a photographing operation switch 26 and a low-pass filter operation switch 27.
  • the photographing operation switch 26 includes various switches such as a power switch and a release switch.
  • the low-pass filter operation switch 27 switches on / off the low-pass filter operation for driving the image sensor 22 in a plane orthogonal to the optical axis Z of the imaging optical system (hereinafter sometimes referred to as an optical axis orthogonal plane). It is a switch for performing various settings related to operation.
  • the low-pass filter operation of the image sensor 22 will be described in detail later.
  • the body main body 20 is connected to the DSP 40 and includes a gyro sensor (a shake detection unit) 28.
  • the gyro sensor 28 detects a shake detection signal (control target signal) indicating a shake in the plane orthogonal to the optical axis of the body body 20 by detecting a moving angular velocity (around the X axis and the Y axis) applied to the body body 20. To do.
  • the image sensor 22 is an image blur correction device (drive mechanism) 50 that is movable in the X-axis direction and the Y-axis direction (two orthogonal directions) orthogonal to the optical axis Z of the photographing optical system. It is mounted on.
  • the image shake correction apparatus 50 includes a fixed support substrate 51 fixed to a structure such as a chassis of the body main body 20, a movable stage 52 that fixes the image sensor 22 and is slidable with respect to the fixed support substrate 51, and fixed support.
  • Magnets M1, M2, M3 fixed on the surface of the substrate 51 facing the movable stage 52, and each magnet M1, fixed on the fixed support substrate 51 with the movable stage 52 sandwiched between the magnets M1, M2, M3,
  • For driving to generate a driving force by receiving a current in a magnetic field of the magnetic circuit fixed to the movable stage 52 and the yokes Y1, Y2, Y3 made of a magnetic material constituting the magnetic circuit between M2 and M3
  • the coils C1, C2, and C3 are provided, and an AC drive signal (AC voltage) is passed (applied) to the drive coils C1, C2, and C3, whereby the fixed support substrate 51 Movable stage 52 (image sensor 22) is adapted to drive the optical axis orthogonal plane.
  • the AC drive signal that flows through the drive coils C1, C2, and C3 is generated by an image sensor drive circuit (drive signal generation unit) 60 described later under the control of the DSP 40.
  • image sensor drive circuit 60 drive signal generation unit
  • the configuration of the image sensor drive circuit 60 and the AC drive signal generated by the image sensor drive circuit 60 will be described in detail later.
  • the image sensor 22 includes a magnetic driving unit including the magnet M1, the yoke Y1, and the driving coil C1, and a magnetic driving unit (two sets of magnetic driving units) including the magnet M2, the yoke Y2, and the driving coil C2.
  • a magnetic driving unit two sets of magnetic driving units
  • magnetic drive means a set of magnetic drive means
  • the magnet M3, the yoke Y3, and the drive coil C3 are orthogonal to the longitudinal direction of the image sensor 22.
  • the fixed support substrate 51 detects the magnetic force of the magnets M1, M2, and M3 in the vicinity (central space) of each of the driving coils C1, C2, and C3, and is orthogonal to the optical axis of the movable stage 52 (image sensor 22).
  • Hall sensors H1, H2, and H3 for detecting a position detection signal indicating the position in the plane are arranged.
  • the position and tilt (rotation) of the movable stage 52 (image sensor 22) are detected by the hall sensors H1 and H2, and the position of the movable stage 52 (image sensor 22) is detected by the hall sensor H3.
  • the DSP 40 includes a shake detection signal indicating a shake in the plane orthogonal to the optical axis of the body main body 20 detected by the gyro sensor 28 and an image sensor detected by the hall sensors H1, H2, and H3 via an image sensor driving circuit 60 described later.
  • the image sensor 22 is driven in the optical axis orthogonal plane by the image blur correction device 50 based on the position detection signal indicating the position in the optical axis orthogonal plane 22. Thereby, the image formation position of the subject image on the image sensor 22 can be displaced, and the image shake due to the camera shake can be corrected. In the present embodiment, this operation is referred to as “image blur correction operation (image blur correction drive) of the image sensor 22”.
  • the image shake correction apparatus 50 drives the image sensor 22 so as to draw a predetermined locus in a plane orthogonal to the optical axis Z of the photographing optical system, and the subject light flux is detected in a plurality of different colors detected by the image sensor 22.
  • an optical low-pass filter effect hereinafter sometimes referred to as an LPF effect
  • this operation is referred to as “low-pass filter operation (LPF operation, LPF drive) of the image sensor 22”.
  • the image shake correction apparatus 50 executes “center holding operation (center holding drive) of the image sensor 22” that holds the image sensor 22 at the center position of the image shake correction operation range (image shake correction drive range). To do. For example, when “image blur correction operation of image sensor 22 (image blur correction drive)” and “LPF operation of image sensor 22 (LPF drive)” are both off, “center holding operation of image sensor 22 (center holding operation”). (Driving) "is turned on, and shooting is performed (the center is maintained without image blur correction).
  • Image sensor 22 image blur correction operation (image blur correction drive)”, “image sensor 22 LPF operation (LPF drive)” and “center holding operation (center holding drive) of image sensor 22” are combined operations of these.
  • a mode realized by the image blur correction device 50 as (combining drive) or a mode in which only one of these operations (drive) is realized by the image blur correction device 50 alone is possible.
  • an image sensor 22 includes a large number of pixels 22a arranged in a matrix at a predetermined pixel pitch P on the light receiving surface, and any one of the color filters R, G, and B in a Bayer array on the front surface of each pixel 22a. Is arranged.
  • Each pixel 22a detects the color of the subject light beam that has passed through one of the color filters R, G, and B on the front surface, that is, photoelectrically converts light of a color component (color band), and the intensity (luminance) ) Is stored.
  • FIG. 4A shows a case where the image sensor 22 is driven so as to draw a rotationally symmetric square locus around the optical axis Z of the photographing optical system.
  • This square locus can be, for example, a square closed path with the pixel pitch P of the image sensor 22 as one side.
  • the image sensor 22 is arranged in units of one pixel pitch P in the Y-axis direction parallel to one (vertical direction) of the pixels 22a orthogonal to each other and in the X-axis direction parallel to the other (horizontal direction). Are alternately moved to form a square path.
  • FIG. 4B shows a case where the image sensor 22 is driven to draw a rotationally symmetric circular locus centering on the optical axis Z of the photographing optical system.
  • This circular locus can be a circular closed path having a radius r of 2 1/2 / 2 times the pixel pitch P of the image sensor 22.
  • the image sensor 22 when the image sensor 22 is driven so as to draw a square or circular predetermined locus during exposure, the light enters the center of each color filter R, G, B (pixel 22a). Since the subject light beam (light beam) is equally incident on the four color filters R, G, B, and G, the same effect as the optical low-pass filter can be obtained. In other words, since light rays incident on any color filter R, G, B, G (pixel 22a) are necessarily incident on the surrounding color filters R, G, B, G (pixel 22a), the optical low-pass filter is also very much optical. The same effect (LPF effect) as the light beam passed through is obtained.
  • the strength of the LPF effect by the image sensor 22 can be increased. It can be switched in stages. That is, the radius r of one side of the square locus or the circular locus is increased (the range of the pixel 22a incident on the pixel 22a (color filter R, G, B, G) having a different detection color of the image sensor 22 on which the subject light ray is incident).
  • the LPF effect is strengthened, while the radius r of one side of the square locus or the circular locus is shortened (pixels 22a (color filters R, G, and B) having different detection colors of the image sensor 22 on which the subject ray is incident. , G)), the LPF effect is weakened.
  • the driving range of the image sensor 22 and the LPF effect can be switched in four stages of “OFF”, “small”, “medium”, and “large”.
  • the driving range of the image sensor 22 and the LPF effect being “OFF” mean that the image sensor 22 is not driven and therefore the LPF effect cannot be obtained.
  • the switching of the driving range of the image sensor 22 and the LPF effect can be performed, for example, by a manual operation of the low-pass filter operation switch 27 or by the DSP 40 automatically based on various shooting condition parameters.
  • the digital camera 10 causes the image sensor 22 to be orthogonal to the optical axis via the image blur correction device 50 by causing an AC drive signal to flow through the drive coils C 1, C 2, and C 3.
  • An image sensor drive circuit (drive signal generation unit) 60 that drives in a plane is provided. The overall operation of the image sensor driving circuit 60 is controlled by the DSP 40.
  • the image sensor driving circuit 60 includes an adding unit 61, a gain unit 62, a low frequency drive signal generating unit 63, a high frequency drive signal generating unit 64, a first superposition synthesis unit 65, A controller 66 and a second superimposing / combining unit 67 are provided.
  • the image sensor drive circuit 60 has a first switch SW1 and a second switch SW2 that are simultaneously switched on and off. When both the first switch SW1 and the second switch SW2 are on, When the first switch SW1 and the second switch SW2 are both off, the image sensor 22 can be moved in the plane orthogonal to the optical axis. Thus, the LPF effect cannot be obtained by minute vibration.
  • the following description of each of the components 61 to 67 of the image sensor driving circuit 60 is a case where both the first switch SW1 and the second switch SW2 are in the on state.
  • the addition unit 61 performs addition processing on a shake detection signal (control target signal) indicating the shake in the plane orthogonal to the optical axis of the body main body 20 detected by the gyro sensor 28.
  • the gain unit 62 amplifies the shake detection signal (control target signal) subjected to the addition processing by the addition unit 61.
  • the gain unit 62 amplifies the shake detection signal subjected to the addition process by the addition unit 61 in accordance with the focal length information of the photographing lens 30 acquired through lens communication with the photographing lens 30. That is, the focal length information of the photographic lens 30 is included in the gain for the gain unit 62 to amplify the shake detection signal.
  • the low frequency drive signal generation unit 63 generates a low frequency drive signal having a drive frequency lower than a predetermined critical frequency.
  • the low frequency drive signal generated by the low frequency drive signal generation unit 63 mainly has a function for causing the image sensor 22 to perform the LPF operation (FIGS. 4A and 4B) in a static friction state. .
  • the high frequency drive signal generator 64 generates a high frequency drive signal having a drive frequency higher than a predetermined critical frequency.
  • the high-frequency drive signal generated by the high-frequency drive signal generation unit 64 mainly has a function of providing a dither effect that always brings the image sensor 22 into a dynamic friction state by applying minute vibrations to the image sensor 22.
  • the “predetermined critical frequency” can be set within a range of 50 Hz to 500 Hz, for example, but a low frequency drive signal having a drive frequency lower than the predetermined critical frequency and a drive frequency higher than the predetermined critical frequency. As long as the high-frequency driving signal can be properly used, there is a degree of freedom in how to determine the “predetermined critical frequency”.
  • the first superimposing / synthesizing unit 65 is generated by the low frequency drive signal generating unit 63 in the shake detection signal (control target signal) amplified by the gain unit 62 after being input from the gyro sensor 28 and added by the adding unit 61.
  • the superposition control target signal is generated by superposing and synthesizing the low-frequency drive signal.
  • the controller 66 receives the superposition control target signal generated by the first superposition synthesis unit 65.
  • PID control can be considered.
  • a duty ratio for driving the driving coils C1, C2, and C3 is output by PWM control.
  • the second superposition synthesis unit 67 superimposes and synthesizes the high frequency drive signal generated by the high frequency drive signal generation unit 64 on the superposition control target signal generated by the first superposition synthesis unit 65 (duty ratio output by the controller 66). As a result, a superimposed drive signal is generated as a drive signal for driving the image sensor 22 in the plane orthogonal to the optical axis via the image blur correction device 50.
  • the image sensor 22 By causing the superimposition drive signal generated by the second superimposition synthesis unit 67 to flow through the driving coils C1, C2, and C3, the image sensor 22 is driven in the plane orthogonal to the optical axis, and the image sensor 22 performs an image blur correction operation.
  • the LPF operation is executed. In this way, a low frequency component for causing the image sensor 22 to perform the LPF operation (FIGS. 4A and 4B) and a minute vibration are applied to the image sensor 22 in the superimposed drive signal, thereby providing a dither effect.
  • the image sensor 22 can be driven and controlled with high accuracy and flexibility.
  • FIG. 6 shows the movement of the image sensor 22 in the plane orthogonal to the optical axis when the LPF effect is turned on and when the LPF effect is turned off.
  • the horizontal axis represents time
  • the vertical axis represents the movement amount.
  • the movement amount on the vertical axis is divided into an X-direction movement amount and a Y-direction movement amount.
  • the control target signal obtained from the gyro sensor 28 includes the low frequency drive signal generated by the low frequency drive signal generation unit 63 and the high frequency drive signal generated by the high frequency drive signal generation unit 64. Are superimposed and the image sensor 22 is driven.
  • FIG. 7 shows signal waveforms of the low frequency drive signal Cx and the high frequency drive signal Dx generated by the low frequency drive signal generation unit 63 and the high frequency drive signal generation unit 64.
  • the DSP 40 includes an exposure time setting unit 41, a frequency determination unit 42, and a duty ratio determination unit 43.
  • the exposure time setting unit 41 sets the exposure time according to various parameters such as the F value of the aperture 32, the shutter speed of the shutter 21, the ISO sensitivity, and the EV value.
  • the frequency determination unit 42 determines the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 according to the exposure time set by the exposure time setting unit 41.
  • the duty ratio determination unit 43 determines the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64 according to the drive frequency of the low frequency drive signal determined by the frequency determination unit 42.
  • the DSP 40 sets the exposure time set by the exposure time setting unit 41, the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63, and the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64.
  • the frequency determination unit 42 and the duty ratio determination unit 43 can execute various controls with reference to this table.
  • the DSP 40 holds a plurality of tables that differ depending on the setting of the LPF effect by the image sensor 22.
  • Table 2 shows a table when the LPF effect by the image sensor 22 held by the DSP 40 is “medium”.
  • the frequency determination unit 42 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “1 Hz (amplitude is 1 pixel).
  • the duty ratio determination unit 43 determines the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64 to be “320 Hz (amplitude is equivalent to a duty ratio of 3%)”.
  • the frequency determination unit 42 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “4 Hz (the amplitude is
  • the duty ratio determination unit 43 determines the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64 to be “320 Hz (amplitude is equivalent to a duty ratio of 4%)”.
  • the frequency determination unit 42 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “32 Hz (
  • the duty ratio determination unit 43 determines the duty ratio of the high-frequency drive signal generated by the high-frequency drive signal generation unit 64 to be “320 Hz (amplitude is equivalent to a duty ratio of 5%)”.
  • the frequency determination unit 42 and the duty ratio determination unit 43 do not perform any control.
  • Table 3 shows a table when the LPF effect by the image sensor 22 held by the DSP 40 is “large”.
  • the frequency determination unit 42 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “1 Hz (amplitude is 1 pixel).
  • the duty ratio determination unit 43 determines the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64 to be “320 Hz (the amplitude is equivalent to a duty ratio of 2%)”.
  • the frequency determination unit 42 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “4 Hz (the amplitude is
  • the duty ratio determination unit 43 determines the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64 to be “320 Hz (amplitude is equivalent to a duty ratio of 3%)”.
  • the frequency determination unit 42 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “32 Hz (
  • the duty ratio determination unit 43 determines the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64 to be “320 Hz (amplitude is equivalent to a duty ratio of 4%)”.
  • the frequency determination unit 42 and the duty ratio determination unit 43 do not perform any control.
  • the duty ratio of the high frequency drive signal is increased to change from the static friction state to the dynamic friction state.
  • the high-frequency drive signal is set so that the drive is sufficiently small without affecting the image quality.
  • the greater the amplitude the larger the duty ratio is calculated by the controller, so even if the movement of the high-frequency drive signal that compensates for the static friction is relatively small, the same tracking ability can be maintained, so this should be reduced. Keep the noise down.
  • FIG. 8 shows the closed loop characteristics of the controller 66. Since the high-frequency drive signal is a disturbance superimposed on the duty ratio, a frequency that is not much compressed by the controller is selected. Specifically, a frequency with a gain smaller than ⁇ 12 db is selected. That is, it is preferable to set the drive frequency of the high frequency drive signal generated by the high frequency drive signal generation unit 64 so that the gain of the closed loop characteristic of the controller is ⁇ 12 dB or less. Thereby, 75% or more of the disturbance is superimposed without being compressed.
  • FIG. 9 shows the movement of the image sensor 22 in the plane orthogonal to the optical axis when the image sensor 22 is driven by a superimposed drive signal on which a high-frequency drive signal is superimposed so that the gain of the closed loop characteristic of the controller is ⁇ 12 dB or less. Is shown. In the example shown in the figure, it is assumed that the output of the shake detection signal by the gyro sensor 28, that is, the case where the disturbance component due to the shake of the body body 20 is zero (when the shake correction is off).
  • a digital camera (photographing apparatus) 10 ′ according to a second embodiment of the present invention will be described.
  • This digital camera 10 ′ is different from the frequency determination unit 42 and the duty ratio determination unit 43 in the digital camera 10 according to the first embodiment shown in FIG. 1 in that the first frequency determination unit 45 and the second frequency determination are performed.
  • the portion 46 is provided.
  • the first frequency determination unit 45 determines the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 according to the exposure time set by the exposure time setting unit 41.
  • the second frequency determination unit 46 determines the drive frequency of the high-frequency drive signal generated by the high-frequency drive signal generation unit 64 according to the drive frequency of the low-frequency drive signal determined by the first frequency determination unit 45.
  • the DSP 40 has an exposure time set by the exposure time setting unit 41, a driving frequency of the low frequency driving signal generated by the low frequency driving signal generating unit 63, and a driving frequency of the high frequency driving signal generated by the high frequency driving signal generating unit 64.
  • the first frequency determination unit 45 and the second frequency determination unit 46 can execute various controls with reference to this table.
  • Table 4 shows an example of a table held by the DSP 40.
  • the first frequency determination unit 45 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “1 Hz (amplitude).
  • the second frequency determination unit 46 determines the drive frequency of the high frequency drive signal generated by the high frequency drive signal generation unit 64 as “10 Hz (amplitude is equivalent to one pixel)”.
  • the first frequency determination unit 45 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “4 Hz”.
  • the second frequency determination unit 46 determines the drive frequency of the high frequency drive signal generated by the high frequency drive signal generation unit 64 to be“ 40 Hz (amplitude is equivalent to one pixel) ”.
  • the first frequency determination unit 45 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63.
  • the frequency determination unit 46 determines “32 Hz (amplitude is equivalent to one pixel)”
  • the second frequency determination unit 46 determines the driving frequency of the high-frequency driving signal generated by the high-frequency driving signal generation unit 64 is “320 Hz (amplitude is equivalent to one pixel)”. To do.
  • the first frequency determination unit 45 and the second frequency determination unit 46 do not perform any control.
  • the high-frequency drive signal By setting the high-frequency drive signal to a frequency 10 times or more that of the low-frequency drive signal, static friction can be sufficiently compensated, and noise can be suppressed by reducing the high-frequency drive frequency.
  • FIG. 11 shows a low frequency drive signal and a high frequency drive signal included in the superimposed drive signal generated by the second superposition synthesis unit 67, that is, the low frequency drive signal generation unit 63 and the high frequency drive signal in the third embodiment of the present invention.
  • generates is shown.
  • FIG. 12 shows the image sensor 22 when the image sensor 22 is driven by a superimposed drive signal on which a high-frequency drive signal is superimposed so that the gain of the closed-loop characteristic of the controller is ⁇ 12 dB or less in the third embodiment of the present invention.
  • the movement in the optical axis orthogonal plane is shown.
  • the output of the shake detection signal by the gyro sensor 28 that is, the case where the disturbance component due to the shake of the body body 20 is zero (when the shake correction is off).
  • the amplitude of the high frequency drive signal Dx generated by the high frequency drive signal generation unit 64 is changed according to the amplitude of the low frequency drive signal Cx generated by the low frequency drive signal generation unit 63. That is, the high-frequency drive signal generated by the high-frequency drive signal generation unit 64 at a timing when the movement of the image sensor (moving member, shake correction member) 22 by the low-frequency drive signal generated by the low-frequency drive signal generation unit 63 is relatively large. The movement of the image sensor (moving member, shake correction member) 22 (the amplitude of the high-frequency drive signal Dx) is relatively small.
  • the movement (the amplitude of the high-frequency drive signal Dx) of the image sensor (moving member, shake correction member) 22 by the signal is relatively large.
  • the low frequency drive signal generation unit 63 generates a low frequency drive signal having a drive frequency lower than a predetermined critical frequency, and performs high frequency drive.
  • the signal generation unit 64 generates a high-frequency drive signal having a drive frequency higher than a predetermined critical frequency
  • the first superposition synthesis unit 65 generates the low-frequency drive generated by the low-frequency drive signal generation unit 63 based on the input control target signal.
  • the superposition control target signal is generated by superimposing the signals
  • the second superposition synthesis unit 67 generates the superposition control target signal generated by the first superposition synthesis unit 65.
  • the high frequency drive signal generated by the high frequency drive signal generation unit 64 A superimposed drive signal as a drive signal is generated by superimposing and synthesizing the signals.
  • the image sensor (moving member, shake correcting member) 22 can be driven and controlled with high accuracy and flexibly, and high-frequency noise can be prevented from causing discomfort to the user.
  • the image sensor 22 is described as the “moving member, shake correction member”, and the mode in which the image sensor 22 is driven in the plane orthogonal to the optical axis has been described.
  • the present invention is limited to this. It is not a thing.
  • a lens (optical element) forming at least a part of the photographic lens group (photographic optical system) 31 is a “moving member, shake correction member”, and this lens (optical element) is provided in the photographic lens 30.
  • a mode of driving in a plane orthogonal to the optical axis by the (drive mechanism) is also possible.
  • both the image sensor 22 and the lens (optical element) forming at least a part of the photographing lens group (photographing optical system) 31 are “moving members and shake correcting members”, and these are driven in an optical axis orthogonal plane.
  • the image blur is corrected by displacing the imaging position of the subject image on the image sensor 22, and the subject light flux is incident on a plurality of pixels having different detection colors of the image sensor 22 to optically. A typical low-pass filter effect can be obtained.
  • the image sensor (moving member, shake correction member) 22 is driven in the plane orthogonal to the optical axis via the image shake correction device (drive mechanism) 50 in order to execute the image shake correction operation and the LPF operation.
  • the direction in which the image sensor (moving member, shake correction member) 22 is driven is not limited to this, and may be any direction different from the optical axis of the photographing optical system.
  • the DSP 40 and the image sensor drive circuit 60 are drawn as separate components (blocks), but an aspect in which these are realized as a single component (block) is also possible.
  • the image blur correction device (drive mechanism) 50 is configured such that the magnets M1, M2, M3 and the yokes Y1, Y2, Y3 are fixed to the fixed support substrate 51, and the drive coil C1,
  • C2 and C3 have been described as an example.
  • the mode in which the body main body 20 and the photographic lens 30 are detachable has been described as an example, but the mode in which the body main body 20 and the photographic lens 30 are not detachable (lens exchangeable) Is also possible.
  • the imaging apparatus and the control method thereof according to the present invention are suitable for use in an imaging apparatus such as a digital camera and the control method thereof.

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Abstract

The purpose of the present invention is to accurately and flexibly control the driving of a moving member, while preventing generation of high frequency noise objectionable to users, in an image capture device and control method therefor which drives the moving member so as to obtain an optical low-pass filter effect. A low frequency drive signal generation unit (63) generates a low frequency drive signal having a drive frequency lower than a predetermined critical frequency. A high frequency drive signal generation unit (64) generates a high frequency drive signal having a drive frequency higher than the predetermined critical frequency. A first overlap synthesis unit (65) causes the low frequency drive signal generated by the low frequency drive signal generation unit (63) to overlap an input control target signal, thereby synthesizing and generating an overlapped control target signal. A second overlap synthesis unit (67) causes the high frequency drive signal generated by the high frequency drive signal generation unit (64) to overlap the overlapped control target signal generated by the first overlap synthesis unit (65), thereby synthesizing and generating an overlapped drive signal serving as a drive signal.

Description

撮影装置及びその制御方法Imaging apparatus and control method thereof
　本発明は、移動部材（振れ補正部材）を撮影光学系の光軸と異なる方向に（例えば光軸直交平面内で）駆動することで光学的なローパスフィルタ効果を得る撮影装置及びその制御方法に関する。 The present invention relates to an imaging apparatus that obtains an optical low-pass filter effect by driving a moving member (shake correction member) in a direction different from the optical axis of an imaging optical system (for example, in a plane orthogonal to the optical axis), and a control method thereof. .
　特許文献１には、撮影光学系の一部をなす移動部材（振れ補正光学系）を光軸直交平面内で駆動（微小振動）することで、光学的なローパスフィルタ効果を得る撮影装置が開示されている。 Patent Document 1 discloses a photographing apparatus that obtains an optical low-pass filter effect by driving (microvibration) a moving member (shake correction optical system) forming a part of a photographing optical system in a plane orthogonal to the optical axis. Has been.
　しかし特許文献１には、移動部材（振れ補正光学系）を画素ピッチ幅で高精度に制御するための具体的な方法は開示されていない。撮像素子は高画素化し続け、画素ピッチが小さくなり続ける中で、画素ピッチ幅での移動部材（振れ補正光学系）の制御が難しくなり続けている。一方、移動部材（振れ補正光学系）を高精度に駆動制御するために、微小な高周波成分を含む高周波駆動信号のみを使用したときには、高周波騒音が発生してユーザに不快感を与えるおそれがある。 However, Patent Document 1 does not disclose a specific method for controlling the moving member (shake correction optical system) with high accuracy by the pixel pitch width. As the image sensor continues to increase in pixels and the pixel pitch continues to decrease, it becomes difficult to control the moving member (blur correction optical system) within the pixel pitch width. On the other hand, when only a high-frequency drive signal including a minute high-frequency component is used to drive and control the moving member (shake correction optical system) with high accuracy, high-frequency noise is generated, which may cause discomfort to the user. .
　特許文献２には、フルイダイジング方法を利用して摩擦力を低減させて駆動制御する際に、フルイダイジングの動作を制御することにより、手ブレ補正の制御時に撮影者に伝わる振動を少なくし、かつ画像ブレを防止する光学機器が開示されている。 Japanese Patent Laid-Open No. 2004-228561 reduces the vibration transmitted to the photographer during the control of camera shake correction by controlling the fluidizing operation when driving control is performed by reducing the frictional force using the fluidizing method. However, an optical apparatus that prevents image blurring is disclosed.
　しかし特許文献２は、露光秒時の長さと露光中か否かの２つのパラメータのみに基づいてフルイダイジングの制御を変更するものにすぎず、駆動制御の柔軟性が著しく低いものである。 However, Patent Document 2 merely changes the fluidizing control based on only two parameters, ie, the length of the exposure time and whether or not the exposure is in progress, and the drive control flexibility is extremely low.
特開２００２－３５４３３６号公報JP 2002-354336 A 特許第３５３０６４３号公報Japanese Patent No. 3530643
　本発明は、以上の問題意識に基づいてなされたものであり、移動部材を駆動することで光学的なローパスフィルタ効果を得る撮影装置及びその制御方法において、移動部材を高精度かつ柔軟に駆動制御するとともに、高周波騒音が発生してユーザに不快感を与えるのを防止することを目的とする。 The present invention has been made on the basis of the above problem awareness, and in the photographing apparatus and its control method for obtaining an optical low-pass filter effect by driving the moving member, the moving member is driven and controlled with high accuracy and flexibility. In addition, it is an object to prevent the user from feeling uncomfortable by generating high frequency noise.
　本発明の撮影装置は、撮影光学系により形成された被写体像を電気的な画素信号に変換するイメージセンサと、前記撮影光学系の少なくとも一部をなす光学要素と前記イメージセンサの少なくとも一方を移動部材とし、この移動部材を前記撮影光学系の光軸と異なる方向に駆動することにより、被写体光束を前記イメージセンサの検出色の異なる複数の画素に入射させて、光学的なローパスフィルタ効果を得る駆動機構と、前記駆動機構を介して前記移動部材を駆動するための駆動信号を生成する駆動信号生成部と、を有する撮影装置において、前記駆動信号生成部は、所定の臨界周波数より低い駆動周波数の低周波駆動信号を生成する低周波駆動信号生成部と、所定の臨界周波数より高い駆動周波数の高周波駆動信号を生成する高周波駆動信号生成部と、入力した制御目標信号に前記低周波駆動信号生成部が生成した低周波駆動信号を重畳合成することにより重畳制御目標信号を生成する第１の重畳合成部と、前記第１の重畳合成部が生成した重畳制御目標信号に前記高周波駆動信号生成部が生成した高周波駆動信号を重畳合成することにより、前記駆動信号としての重畳駆動信号を生成する第２の重畳合成部と、を有することを特徴としている。 An imaging apparatus of the present invention moves at least one of an image sensor that converts a subject image formed by an imaging optical system into an electrical pixel signal, an optical element that forms at least a part of the imaging optical system, and the image sensor. By driving this moving member in a direction different from the optical axis of the photographing optical system, the subject luminous flux is made incident on a plurality of pixels having different detection colors of the image sensor, and an optical low-pass filter effect is obtained. In a photographing apparatus having a driving mechanism and a driving signal generating unit that generates a driving signal for driving the moving member via the driving mechanism, the driving signal generating unit has a driving frequency lower than a predetermined critical frequency. A low-frequency drive signal generating unit that generates a low-frequency drive signal, and a high-frequency drive that generates a high-frequency drive signal having a drive frequency higher than a predetermined critical frequency. A signal generation unit, a first superposition synthesis unit that generates a superposition control target signal by superimposing and synthesizing the low frequency drive signal generated by the low frequency drive signal generation unit on the input control target signal, and the first superposition synthesis unit A second superposition synthesis unit that generates a superposition drive signal as the drive signal by superposing and synthesizing the high frequency drive signal generated by the high frequency drive signal generation unit on the superposition control target signal generated by the superposition synthesis unit; It is characterized by having.
　本発明の撮影装置は、露光時間を設定する露光時間設定部と、前記露光時間設定部が設定した露光時間に応じて、前記低周波駆動信号生成部が生成する低周波駆動信号の駆動周波数を決定する周波数決定部と、前記周波数決定部が決定した低周波駆動信号の駆動周波数に応じて、前記高周波駆動信号生成部が生成する高周波駆動信号のデューティ比を決定するデューティ比決定部と、をさらに有することが好ましい。 An imaging apparatus according to the present invention includes an exposure time setting unit for setting an exposure time, and a driving frequency of the low frequency drive signal generated by the low frequency drive signal generation unit according to the exposure time set by the exposure time setting unit. A frequency determining unit for determining, and a duty ratio determining unit for determining a duty ratio of the high frequency drive signal generated by the high frequency drive signal generating unit according to the drive frequency of the low frequency drive signal determined by the frequency determining unit. Furthermore, it is preferable to have.
　あるいは、本発明の撮影装置は、露光時間を設定する露光時間設定部と、前記露光時間設定部が設定した露光時間に応じて、前記低周波駆動信号生成部が生成する低周波駆動信号の駆動周波数を決定する第１の周波数決定部と、前記第１の周波数決定部が決定した低周波駆動信号の駆動周波数に応じて、前記高周波駆動信号生成部が生成する高周波駆動信号の駆動周波数を決定する第２の周波数決定部と、をさらに有することが好ましい。 Alternatively, the imaging apparatus of the present invention includes an exposure time setting unit that sets an exposure time, and driving of a low frequency drive signal generated by the low frequency drive signal generation unit according to the exposure time set by the exposure time setting unit. A first frequency determining unit that determines a frequency, and a driving frequency of the high-frequency driving signal generated by the high-frequency driving signal generating unit is determined according to the driving frequency of the low-frequency driving signal determined by the first frequency determining unit. And a second frequency determination unit.
　前記高周波駆動信号生成部が生成する高周波駆動信号の駆動周波数は、制御器の閉ループ特性のゲインが－１２ｄＢ以下であることが好ましい。 The drive frequency of the high frequency drive signal generated by the high frequency drive signal generator is preferably such that the gain of the closed loop characteristic of the controller is -12 dB or less.
　前記低周波駆動信号生成部が生成した低周波駆動信号による前記移動部材の動きが相対的に大きいタイミングで、前記高周波駆動信号生成部が生成した高周波駆動信号による前記移動部材の動きが相対的に小さいことが好ましい。 The movement of the moving member due to the high-frequency drive signal generated by the high-frequency drive signal generation unit is relatively high when the movement of the moving member due to the low-frequency drive signal generated by the low-frequency drive signal generation unit is relatively large. Small is preferable.
　前記低周波駆動信号生成部が生成する低周波駆動信号の振幅に応じて、前記高周波駆動信号生成部が生成する高周波駆動信号の振幅を変更することが好ましい。 It is preferable that the amplitude of the high frequency drive signal generated by the high frequency drive signal generator is changed according to the amplitude of the low frequency drive signal generated by the low frequency drive signal generator.
　本発明の撮影装置は、前記イメージセンサを搭載したボディ本体の振れを検出する振れ検出部をさらに有しており、前記振れ検出部は、検出した振れ検出信号を前記制御目標信号として出力することが好ましい。 The photographing apparatus of the present invention further includes a shake detection unit that detects a shake of the body main body on which the image sensor is mounted, and the shake detection unit outputs the detected shake detection signal as the control target signal. Is preferred.
　本発明の撮影装置の制御方法は、撮影光学系により形成された被写体像を電気的な画素信号に変換するイメージセンサと、前記撮影光学系の少なくとも一部をなす光学要素と前記イメージセンサの少なくとも一方を移動部材とし、この移動部材を前記撮影光学系の光軸と異なる方向に駆動することにより、被写体光束を前記イメージセンサの検出色の異なる複数の画素に入射させて、光学的なローパスフィルタ効果を得る駆動機構と、を有する撮影装置の制御方法において、前記駆動機構を介して前記移動部材を駆動するための駆動信号を生成する駆動信号生成ステップを有し、前記駆動信号生成ステップは、所定の臨界周波数より低い駆動周波数の低周波駆動信号を生成する低周波駆動信号生成ステップと、所定の臨界周波数より高い駆動周波数の高周波駆動信号を生成する高周波駆動信号生成ステップと、入力した制御目標信号に前記低周波駆動信号生成ステップで生成した低周波駆動信号を重畳合成することにより重畳制御目標信号を生成する第１の重畳合成ステップと、前記第１の重畳合成ステップで生成した重畳制御目標信号に前記高周波駆動信号生成ステップで生成した高周波駆動信号を重畳合成することにより、前記駆動信号としての重畳駆動信号を生成する第２の重畳合成ステップと、を有することを特徴としている。 According to another aspect of the present invention, there is provided a method for controlling an imaging apparatus, comprising: an image sensor that converts an object image formed by an imaging optical system into an electrical pixel signal; an optical element that forms at least a part of the imaging optical system; One of them is a moving member, and this moving member is driven in a direction different from the optical axis of the photographing optical system, so that the subject luminous flux is incident on a plurality of pixels having different detection colors of the image sensor, and an optical low-pass filter. A drive mechanism for obtaining an effect, and a drive signal generation step for generating a drive signal for driving the moving member via the drive mechanism, wherein the drive signal generation step includes: A low-frequency drive signal generating step for generating a low-frequency drive signal having a drive frequency lower than a predetermined critical frequency; and a drive higher than the predetermined critical frequency. A high-frequency drive signal generating step for generating a high-frequency drive signal having a frequency, and a first control signal for generating a superposition control target signal by superimposing and synthesizing the low-frequency drive signal generated in the low-frequency drive signal generation step on the input control target signal The superposition drive signal as the drive signal is generated by superposing and synthesizing the high frequency drive signal generated in the high frequency drive signal generation step on the superposition control target signal generated in the first superposition synthesis step. And a second superimposing and synthesizing step.
　本発明の撮影装置の制御方法は、露光時間を設定する露光時間設定ステップと、前記露光時間設定ステップで設定した露光時間に応じて、前記低周波駆動信号生成ステップで生成する低周波駆動信号の駆動周波数を決定する周波数決定ステップと、前記周波数決定ステップで決定した低周波駆動信号の駆動周波数に応じて、前記高周波駆動信号生成ステップで生成する高周波駆動信号のデューティ比を決定するデューティ比決定ステップと、をさらに有することが好ましい。 The method for controlling an imaging apparatus according to the present invention includes: an exposure time setting step for setting an exposure time; and a low frequency drive signal generated in the low frequency drive signal generation step in accordance with the exposure time set in the exposure time setting step. A frequency determining step for determining a driving frequency, and a duty ratio determining step for determining a duty ratio of the high-frequency driving signal generated in the high-frequency driving signal generating step according to the driving frequency of the low-frequency driving signal determined in the frequency determining step It is preferable to further include
　あるいは、本発明の撮影装置の制御方法は、露光時間を設定する露光時間設定ステップと、前記露光時間設定ステップで設定した露光時間に応じて、前記低周波駆動信号生成ステップで生成する低周波駆動信号の駆動周波数を決定する第１の周波数決定ステップと、前記第１の周波数決定ステップで決定した低周波駆動信号の駆動周波数に応じて、前記高周波駆動信号生成ステップで生成する高周波駆動信号の駆動周波数を決定する第２の周波数決定ステップと、をさらに有することが好ましい。 Alternatively, the control method of the photographing apparatus of the present invention includes an exposure time setting step for setting an exposure time, and a low frequency drive generated in the low frequency drive signal generation step according to the exposure time set in the exposure time setting step. A first frequency determining step for determining a driving frequency of the signal, and driving of the high-frequency driving signal generated in the high-frequency driving signal generating step according to the driving frequency of the low-frequency driving signal determined in the first frequency determining step Preferably, the method further comprises a second frequency determination step for determining a frequency.
　前記高周波駆動信号生成ステップで生成する高周波駆動信号の駆動周波数は、制御器の閉ループ特性のゲインが－１２ｄＢ以下であることが好ましい。 The drive frequency of the high-frequency drive signal generated in the high-frequency drive signal generation step is preferably such that the gain of the closed-loop characteristic of the controller is −12 dB or less.
　前記低周波駆動信号生成ステップで生成した低周波駆動信号による前記移動部材の動きが相対的に大きいタイミングで、前記高周波駆動信号生成ステップで生成した高周波駆動信号による前記移動部材の動きが相対的に小さいことが好ましい。 The movement of the moving member due to the high frequency drive signal generated in the high frequency drive signal generation step is relatively high when the movement of the moving member due to the low frequency drive signal generated in the low frequency drive signal generation step is relatively large. Small is preferable.
　前記低周波駆動信号生成ステップで生成する低周波駆動信号の振幅に応じて、前記高周波駆動信号生成ステップで生成する高周波駆動信号の振幅を変更することが好ましい。 It is preferable that the amplitude of the high frequency drive signal generated in the high frequency drive signal generation step is changed according to the amplitude of the low frequency drive signal generated in the low frequency drive signal generation step.
　本発明の撮影装置の制御方法は、前記イメージセンサを搭載したボディ本体の振れを検出する振れ検出ステップをさらに有しており、前記振れ検出ステップでは、検出した振れ検出信号を前記制御目標信号として出力することが好ましい。 The control method of the photographing apparatus of the present invention further includes a shake detection step of detecting a shake of the body body on which the image sensor is mounted, and in the shake detection step, the detected shake detection signal is used as the control target signal. It is preferable to output.
　本発明によれば、移動部材を駆動することで光学的なローパスフィルタ効果を得る撮影装置及びその制御方法において、移動部材を高精度かつ柔軟に駆動制御するとともに、高周波騒音が発生してユーザに不快感を与えるのを防止することができる。 According to the present invention, in an imaging device and a control method thereof that obtain an optical low-pass filter effect by driving a moving member, the moving member is driven and controlled with high accuracy and flexibility, and high-frequency noise is generated to the user. An unpleasant feeling can be prevented.
本発明の第１実施形態に係るデジタルカメラ（撮影装置）の要部構成を示すブロック図である。1 is a block diagram illustrating a main configuration of a digital camera (photographing apparatus) according to a first embodiment of the present invention. 像振れ補正装置（駆動機構）の要部構成を示すブロック図である。FIG. 3 is a block diagram illustrating a configuration of a main part of an image blur correction device (drive mechanism). 像振れ補正装置（駆動機構）の構成を示す側面図である。It is a side view which shows the structure of an image shake correction apparatus (drive mechanism). 図４（Ａ）、（Ｂ）は所定軌跡を描くようにイメージセンサを駆動することで光学的なローパスフィルタ効果を与えるための動作を示す図であり、図４（Ａ）は撮影光学系の光軸を中心とする回転対称な正方形軌跡を描くようにイメージセンサを駆動する場合、図４（Ｂ）は撮影光学系の光軸を中心とする回転対称な円形軌跡を描くようにイメージセンサを駆動する場合をそれぞれ示している。4A and 4B are diagrams showing an operation for giving an optical low-pass filter effect by driving the image sensor so as to draw a predetermined locus, and FIG. 4A is a diagram of the photographing optical system. When the image sensor is driven to draw a rotationally symmetric square locus centered on the optical axis, FIG. 4B shows the image sensor being drawn so as to draw a rotationally symmetric circular locus centered on the optical axis of the imaging optical system. Each case of driving is shown. イメージセンサ駆動回路（駆動信号生成部）の構成を示す機能ブロック図である。It is a functional block diagram which shows the structure of an image sensor drive circuit (drive signal generation part). ＬＰＦ効果をオンにした場合とＬＰＦ効果をオフにした場合におけるイメージセンサの光軸直交平面内での動きを示す図である。It is a figure which shows the motion in the optical axis orthogonal plane of the image sensor in the case where the LPF effect is turned on and the case where the LPF effect is turned off. 第２の重畳合成部が生成する重畳駆動信号に含まれる低周波駆動信号と高周波駆動信号の信号波形を示す図である。It is a figure which shows the signal waveform of the low frequency drive signal and high frequency drive signal which are contained in the superposition drive signal which a 2nd superposition synthetic | combination part produces | generates. コントローラの閉ループ実施例を示す図である。It is a figure which shows the closed loop Example of a controller. 制御器の閉ループ特性のゲインが－１２ｄＢ以下となるような高周波駆動信号を重畳した重畳駆動信号によってイメージセンサを駆動した場合における該イメージセンサの光軸直交平面内での動きを示す図である。It is a figure which shows the motion in the optical axis orthogonal plane of the image sensor when the image sensor is driven by the superimposed drive signal on which the high-frequency drive signal is superimposed so that the gain of the closed loop characteristic of the controller is −12 dB or less. 本発明の第２実施形態に係るデジタルカメラ（撮影装置）の要部構成を示すブロック図である。It is a block diagram which shows the principal part structure of the digital camera (imaging device) which concerns on 2nd Embodiment of this invention. 本発明の第３実施形態に係るデジタルカメラを説明するための図７に対応する図である。It is a figure corresponding to FIG. 7 for demonstrating the digital camera which concerns on 3rd Embodiment of this invention. 本発明の第３実施形態に係るデジタルカメラを説明するための図９に対応する図である。It is a figure corresponding to FIG. 9 for demonstrating the digital camera which concerns on 3rd Embodiment of this invention.
＜第１実施形態＞
　図１ないし図９を参照して、本発明の第１実施形態に係るデジタルカメラ（撮影装置）１０について説明する。 <First Embodiment>
A digital camera (photographing apparatus) 10 according to a first embodiment of the present invention will be described with reference to FIGS.
　図１に示すように、デジタルカメラ１０は、ボディ本体２０と、このボディ本体２０に着脱可能（レンズ交換可能）な撮影レンズ３０とを備えている。撮影レンズ３０は、被写体側（図１中の左側）から像面側（図１中の右側）に向かって順に、撮影レンズ群（撮影光学系、移動部材、振れ補正部材）３１と、絞り（撮影光学系）３２とを備えている。ボディ本体２０は、被写体側（図１中の左側）から像面側（図１中の右側）に向かって順に、シャッタ（撮影光学系）２１と、イメージセンサ（移動部材、振れ補正部材）２２とを備えている。またボディ本体２０は、撮影レンズ３０への装着状態で絞り３２とシャッタ２１を駆動制御する絞り／シャッタ駆動回路２３を備えている。撮影レンズ群３１から入射し、絞り３２とシャッタ２１を通った被写体光束による被写体像が、イメージセンサ２２の受光面上に形成される。イメージセンサ２２の受光面上に形成された被写体像は、マトリックス状に配置された多数の画素によって、電気的な画素信号に変換され、画像データ（静止画データ、動画データ）としてＤＳＰ４０に出力される。ＤＳＰ４０は、イメージセンサ２２から入力した画像データに所定の画像処理を施して、これをＬＣＤ２４に表示し、画像メモリ２５に記憶する。なお、図１では、撮影レンズ群３１が単一のレンズ（光学要素）からなるように描いているが、実際の撮影レンズ群３１は、例えば、固定レンズ、変倍時に移動する変倍レンズ、フォーカシング時に移動するフォーカシングレンズなどの複数枚のレンズ（光学要素）からなる。 As shown in FIG. 1, the digital camera 10 includes a body main body 20 and a photographic lens 30 that can be attached to and detached from the body main body 20 (lens exchangeable). The photographic lens 30 includes, in order from the subject side (left side in FIG. 1) to the image plane side (right side in FIG. 1), a photographic lens group (photographic optical system, moving member, shake correction member) 31, and aperture ( Photographing optical system) 32. The body main body 20 has a shutter (photographing optical system) 21 and an image sensor (moving member, shake correction member) 22 in order from the subject side (left side in FIG. 1) to the image plane side (right side in FIG. 1). And. The body body 20 also includes a diaphragm / shutter drive circuit 23 that controls driving of the diaphragm 32 and the shutter 21 in a state where the body body 20 is attached to the photographing lens 30. A subject image is formed on the light receiving surface of the image sensor 22 by the subject light flux that enters from the photographing lens group 31 and passes through the aperture 32 and the shutter 21. The subject image formed on the light receiving surface of the image sensor 22 is converted into an electrical pixel signal by a large number of pixels arranged in a matrix, and is output to the DSP 40 as image data (still image data, moving image data). The The DSP 40 performs predetermined image processing on the image data input from the image sensor 22, displays it on the LCD 24, and stores it in the image memory 25. In FIG. 1, the photographic lens group 31 is drawn so as to be composed of a single lens (optical element). However, the actual photographic lens group 31 may be, for example, a fixed lens, a variable magnification lens that moves during magnification, It consists of a plurality of lenses (optical elements) such as a focusing lens that moves during focusing.
　図示は省略しているが、イメージセンサ２２は、パッケージと、このパッケージに収納される固体撮像素子チップと、この固体撮像素子チップを密封保護するようにパッケージに固定される蓋部材とを含む複数の構成要素からなる。本明細書において、「イメージセンサ（移動部材、振れ補正部材）２２を駆動する」とは、「イメージセンサ（移動部材、振れ補正部材）２２の複数の構成要素のうち被写体光束が通過する少なくとも一部を駆動する」ことを意味する。 Although not shown, the image sensor 22 includes a plurality of packages, a solid-state image sensor chip housed in the package, and a lid member fixed to the package so as to hermetically protect the solid-state image sensor chip. It consists of the following components. In this specification, “to drive the image sensor (moving member, shake correction member) 22” means “at least one of the plurality of components of the image sensor (moving member, shake correction member) 22 through which the subject luminous flux passes. Means to drive the part.
　撮影レンズ３０は、撮影レンズ群３１の解像力（ＭＴＦ）情報や絞り３２の開口径（絞り値）情報などの各種情報を記憶した通信用メモリ３３を搭載している。撮影レンズ３０をボディ本体２０に装着した状態では、通信用メモリ３３が記憶した各種情報がＤＳＰ４０に読み込まれる。 The photographing lens 30 includes a communication memory 33 that stores various information such as resolving power (MTF) information of the photographing lens group 31 and aperture diameter (aperture value) information of the diaphragm 32. In a state where the photographic lens 30 is attached to the body main body 20, various information stored in the communication memory 33 is read into the DSP 40.
　ボディ本体２０は、ＤＳＰ４０に接続させて、撮影操作スイッチ２６とローパスフィルタ操作スイッチ２７を備えている。撮影操作スイッチ２６は、電源スイッチやレリーズスイッチなどの各種スイッチからなる。ローパスフィルタ操作スイッチ２７は、イメージセンサ２２を撮影光学系の光軸Ｚと直交する平面内（以下、光軸直交平面内と呼ぶことがある）で駆動するローパスフィルタ動作のオンオフの切替え、ローパスフィルタ動作に関する各種設定などを行うためのスイッチである。イメージセンサ２２のローパスフィルタ動作については後に詳細に説明する。 The body main body 20 is connected to the DSP 40 and includes a photographing operation switch 26 and a low-pass filter operation switch 27. The photographing operation switch 26 includes various switches such as a power switch and a release switch. The low-pass filter operation switch 27 switches on / off the low-pass filter operation for driving the image sensor 22 in a plane orthogonal to the optical axis Z of the imaging optical system (hereinafter sometimes referred to as an optical axis orthogonal plane). It is a switch for performing various settings related to operation. The low-pass filter operation of the image sensor 22 will be described in detail later.
　ボディ本体２０は、ＤＳＰ４０に接続させて、ジャイロセンサ（振れ検出部）２８を備えている。ジャイロセンサ２８は、ボディ本体２０に加わる移動角速度（Ｘ軸とＹ軸周り）を検出することで、該ボディ本体２０の光軸直交平面内の振れを示す振れ検出信号（制御目標信号）を検出する。 The body main body 20 is connected to the DSP 40 and includes a gyro sensor (a shake detection unit) 28. The gyro sensor 28 detects a shake detection signal (control target signal) indicating a shake in the plane orthogonal to the optical axis of the body body 20 by detecting a moving angular velocity (around the X axis and the Y axis) applied to the body body 20. To do.
　図１ないし図３に示すように、イメージセンサ２２は、撮影光学系の光軸Ｚと直交するＸ軸方向とＹ軸方向（直交二方向）に移動可能に像振れ補正装置（駆動機構）５０に搭載されている。像振れ補正装置５０は、ボディ本体２０のシャーシなどの構造物に固定される固定支持基板５１と、イメージセンサ２２を固定した、固定支持基板５１に対してスライド可能な可動ステージ５２と、固定支持基板５１の可動ステージ５２との対向面に固定した磁石Ｍ１、Ｍ２、Ｍ３と、固定支持基板５１に可動ステージ５２を挟んで各磁石Ｍ１、Ｍ２、Ｍ３と対向させて固定した、各磁石Ｍ１、Ｍ２、Ｍ３との間に磁気回路を構成する磁性体からなるヨークＹ１、Ｙ２、Ｙ３と、可動ステージ５２に固定した、前記磁気回路の磁界内において電流を受けることにより駆動力を発生する駆動用コイルＣ１、Ｃ２、Ｃ３を有し、駆動用コイルＣ１、Ｃ２、Ｃ３に交流駆動信号（交流電圧）を流す（印加する）ことにより、固定支持基板５１に対して可動ステージ５２（イメージセンサ２２）が光軸直交平面内で駆動するようになっている。駆動用コイルＣ１、Ｃ２、Ｃ３に流す交流駆動信号は、ＤＳＰ４０による制御の下、後述するイメージセンサ駆動回路（駆動信号生成部）６０によって生成される。イメージセンサ駆動回路６０の構成及び該イメージセンサ駆動回路６０が生成する交流駆動信号については後に詳細に説明する。 As shown in FIGS. 1 to 3, the image sensor 22 is an image blur correction device (drive mechanism) 50 that is movable in the X-axis direction and the Y-axis direction (two orthogonal directions) orthogonal to the optical axis Z of the photographing optical system. It is mounted on. The image shake correction apparatus 50 includes a fixed support substrate 51 fixed to a structure such as a chassis of the body main body 20, a movable stage 52 that fixes the image sensor 22 and is slidable with respect to the fixed support substrate 51, and fixed support. Magnets M1, M2, M3 fixed on the surface of the substrate 51 facing the movable stage 52, and each magnet M1, fixed on the fixed support substrate 51 with the movable stage 52 sandwiched between the magnets M1, M2, M3, For driving to generate a driving force by receiving a current in a magnetic field of the magnetic circuit fixed to the movable stage 52 and the yokes Y1, Y2, Y3 made of a magnetic material constituting the magnetic circuit between M2 and M3 The coils C1, C2, and C3 are provided, and an AC drive signal (AC voltage) is passed (applied) to the drive coils C1, C2, and C3, whereby the fixed support substrate 51 Movable stage 52 (image sensor 22) is adapted to drive the optical axis orthogonal plane. The AC drive signal that flows through the drive coils C1, C2, and C3 is generated by an image sensor drive circuit (drive signal generation unit) 60 described later under the control of the DSP 40. The configuration of the image sensor drive circuit 60 and the AC drive signal generated by the image sensor drive circuit 60 will be described in detail later.
　本実施形態では、磁石Ｍ１、ヨークＹ１及び駆動用コイルＣ１からなる磁気駆動手段と、磁石Ｍ２、ヨークＹ２及び駆動用コイルＣ２からなる磁気駆動手段（２組の磁気駆動手段）とがイメージセンサ２２の長手方向（水平方向、Ｘ軸方向）に所定間隔で配置され、磁石Ｍ３、ヨークＹ３及び駆動用コイルＣ３からなる磁気駆動手段（１組の磁気駆動手段）がイメージセンサ２２の長手方向と直交する短手方向（鉛直（垂直）方向、Ｙ軸方向）に配置されている。 In the present embodiment, the image sensor 22 includes a magnetic driving unit including the magnet M1, the yoke Y1, and the driving coil C1, and a magnetic driving unit (two sets of magnetic driving units) including the magnet M2, the yoke Y2, and the driving coil C2. Are arranged at predetermined intervals in the longitudinal direction (horizontal direction, X-axis direction), and magnetic drive means (a set of magnetic drive means) including the magnet M3, the yoke Y3, and the drive coil C3 are orthogonal to the longitudinal direction of the image sensor 22. Are arranged in the short direction (vertical (vertical) direction, Y-axis direction).
　さらに固定支持基板５１には、各駆動用コイルＣ１、Ｃ２、Ｃ３の近傍（中央空間部）に、磁石Ｍ１、Ｍ２、Ｍ３の磁力を検出して可動ステージ５２（イメージセンサ２２）の光軸直交平面内の位置を示す位置検出信号を検出するホールセンサＨ１、Ｈ２、Ｈ３が配置されている。ホールセンサＨ１、Ｈ２により可動ステージ５２（イメージセンサ２２）のＹ軸方向位置及び傾き（回転）が検出され、ホールセンサＨ３により可動ステージ５２（イメージセンサ２２）のＸ軸方向位置が検出される。ＤＳＰ４０は、後述するイメージセンサ駆動回路６０を介して、ジャイロセンサ２８が検出したボディ本体２０の光軸直交平面内の振れを示す振れ検出信号と、ホールセンサＨ１、Ｈ２、Ｈ３が検出したイメージセンサ２２の光軸直交平面内の位置を示す位置検出信号とに基づいて、像振れ補正装置５０によってイメージセンサ２２を光軸直交平面内で駆動する。これにより、イメージセンサ２２上への被写体像の結像位置を変位させて、手振れに起因する像振れを補正することができる。本実施形態ではこの動作を「イメージセンサ２２の像振れ補正動作（像振れ補正駆動）」と呼ぶ。 Further, the fixed support substrate 51 detects the magnetic force of the magnets M1, M2, and M3 in the vicinity (central space) of each of the driving coils C1, C2, and C3, and is orthogonal to the optical axis of the movable stage 52 (image sensor 22). Hall sensors H1, H2, and H3 for detecting a position detection signal indicating the position in the plane are arranged. The position and tilt (rotation) of the movable stage 52 (image sensor 22) are detected by the hall sensors H1 and H2, and the position of the movable stage 52 (image sensor 22) is detected by the hall sensor H3. The DSP 40 includes a shake detection signal indicating a shake in the plane orthogonal to the optical axis of the body main body 20 detected by the gyro sensor 28 and an image sensor detected by the hall sensors H1, H2, and H3 via an image sensor driving circuit 60 described later. The image sensor 22 is driven in the optical axis orthogonal plane by the image blur correction device 50 based on the position detection signal indicating the position in the optical axis orthogonal plane 22. Thereby, the image formation position of the subject image on the image sensor 22 can be displaced, and the image shake due to the camera shake can be corrected. In the present embodiment, this operation is referred to as “image blur correction operation (image blur correction drive) of the image sensor 22”.
　本実施形態の像振れ補正装置５０は、撮影光学系の光軸Ｚと直交する平面内において所定軌跡を描くようにイメージセンサ２２を駆動して、被写体光束をイメージセンサ２２の検出色の異なる複数の画素に入射させることにより、光学的なローパスフィルタ効果（以下、ＬＰＦ効果と呼ぶことがある）を与える。本実施形態ではこの動作を「イメージセンサ２２のローパスフィルタ動作（ＬＰＦ動作、ＬＰＦ駆動）」と呼ぶ。 The image shake correction apparatus 50 according to the present embodiment drives the image sensor 22 so as to draw a predetermined locus in a plane orthogonal to the optical axis Z of the photographing optical system, and the subject light flux is detected in a plurality of different colors detected by the image sensor 22. In this case, an optical low-pass filter effect (hereinafter sometimes referred to as an LPF effect) is given. In the present embodiment, this operation is referred to as “low-pass filter operation (LPF operation, LPF drive) of the image sensor 22”.
　本実施形態の像振れ補正装置５０は、イメージセンサ２２をその像振れ補正動作範囲（像振れ補正駆動範囲）の中央位置で保持する「イメージセンサ２２の中央保持動作（中央保持駆動）」を実行する。例えば、「イメージセンサ２２の像振れ補正動作（像振れ補正駆動）」と「イメージセンサ２２のＬＰＦ動作（ＬＰＦ駆動）」がともにオフの場合には、「イメージセンサ２２の中央保持動作（中央保持駆動）」のみをオンにして撮影が行われる（像振れ補正を行わなくても中央保持は行う）。 The image shake correction apparatus 50 according to the present embodiment executes “center holding operation (center holding drive) of the image sensor 22” that holds the image sensor 22 at the center position of the image shake correction operation range (image shake correction drive range). To do. For example, when “image blur correction operation of image sensor 22 (image blur correction drive)” and “LPF operation of image sensor 22 (LPF drive)” are both off, “center holding operation of image sensor 22 (center holding operation”). (Driving) "is turned on, and shooting is performed (the center is maintained without image blur correction).
　「イメージセンサ２２の像振れ補正動作（像振れ補正駆動）」、「イメージセンサ２２のＬＰＦ動作（ＬＰＦ駆動）」及び「イメージセンサ２２の中央保持動作（中央保持駆動）」は、これらの合成動作（合成駆動）として像振れ補正装置５０によって実現される態様、あるいは、これらのいずれか１つの動作（駆動）のみが単独で像振れ補正装置５０によって実現される態様が可能である。 “Image sensor 22 image blur correction operation (image blur correction drive)”, “image sensor 22 LPF operation (LPF drive)” and “center holding operation (center holding drive) of image sensor 22” are combined operations of these. A mode realized by the image blur correction device 50 as (combining drive) or a mode in which only one of these operations (drive) is realized by the image blur correction device 50 alone is possible.
　図４（Ａ）、（Ｂ）を参照して、像振れ補正装置５０が、所定軌跡を描くようにイメージセンサ２２を駆動して、該イメージセンサ２２によってＬＰＦ効果を与えるＬＰＦ動作について説明する。同図において、イメージセンサ２２は、受光面にマトリックス状に所定の画素ピッチＰで配置された多数の画素２２ａを備え、各画素２２ａの前面にベイヤ配列のカラーフィルタＲ、Ｇ、Ｂのいずれかが配置されている。各画素２２ａは、前面のいずれかのカラーフィルタＲ、Ｇ、Ｂを透過して入射した被写体光線の色を検出、つまり、色成分（色帯域）の光を光電変換し、その強さ（輝度）に応じた電荷を蓄積する。 4A and 4B, an LPF operation in which the image blur correction apparatus 50 drives the image sensor 22 so as to draw a predetermined locus and gives the LPF effect by the image sensor 22 will be described. In the figure, an image sensor 22 includes a large number of pixels 22a arranged in a matrix at a predetermined pixel pitch P on the light receiving surface, and any one of the color filters R, G, and B in a Bayer array on the front surface of each pixel 22a. Is arranged. Each pixel 22a detects the color of the subject light beam that has passed through one of the color filters R, G, and B on the front surface, that is, photoelectrically converts light of a color component (color band), and the intensity (luminance) ) Is stored.
　図４（Ａ）は、イメージセンサ２２を、撮影光学系の光軸Ｚを中心とする回転対称な正方形軌跡を描くように駆動する場合を示している。この正方形軌跡は、例えば、イメージセンサ２２の画素ピッチＰを一辺とした正方形の閉じた経路とすることができる。図４（Ａ）では、イメージセンサ２２を、画素２２ａの互いに直交する並び方向の一方（鉛直方向）と平行なＹ軸方向、他方（水平方向）と平行なＸ軸方向に１画素ピッチＰ単位で交互にかつ正方形経路となるように移動させている。 FIG. 4A shows a case where the image sensor 22 is driven so as to draw a rotationally symmetric square locus around the optical axis Z of the photographing optical system. This square locus can be, for example, a square closed path with the pixel pitch P of the image sensor 22 as one side. In FIG. 4A, the image sensor 22 is arranged in units of one pixel pitch P in the Y-axis direction parallel to one (vertical direction) of the pixels 22a orthogonal to each other and in the X-axis direction parallel to the other (horizontal direction). Are alternately moved to form a square path.
　図４（Ｂ）は、イメージセンサ２２を、撮影光学系の光軸Ｚを中心とする回転対称な円形軌跡を描くように駆動する場合を示している。この円形軌跡は、イメージセンサ２２の画素ピッチＰの２1/2／２倍を半径ｒとする円形の閉じた経路とすることができる。 FIG. 4B shows a case where the image sensor 22 is driven to draw a rotationally symmetric circular locus centering on the optical axis Z of the photographing optical system. This circular locus can be a circular closed path having a radius r of 2 1/2 / 2 times the pixel pitch P of the image sensor 22.
　図４（Ａ）、（Ｂ）のように、露光中にイメージセンサ２２を正方形または円形の所定軌跡を描くように駆動すると、各カラーフィルタＲ、Ｇ、Ｂ（画素２２ａ）の中央に入射した被写体光線（光束）が、４個のカラーフィルタＲ、Ｇ、Ｂ、Ｇに均等に入射するので、光学的なローパスフィルタと同等の効果が得られる。つまり、どのカラーフィルタＲ、Ｇ、Ｂ、Ｇ（画素２２ａ）に入射した光線も、必ずその周辺のカラーフィルタＲ、Ｇ、Ｂ、Ｇ（画素２２ａ）に入射するので、恰も光学的なローパスフィルタを光線が通過したのと同等の効果（ＬＰＦ効果）が得られる。 As shown in FIGS. 4A and 4B, when the image sensor 22 is driven so as to draw a square or circular predetermined locus during exposure, the light enters the center of each color filter R, G, B (pixel 22a). Since the subject light beam (light beam) is equally incident on the four color filters R, G, B, and G, the same effect as the optical low-pass filter can be obtained. In other words, since light rays incident on any color filter R, G, B, G (pixel 22a) are necessarily incident on the surrounding color filters R, G, B, G (pixel 22a), the optical low-pass filter is also very much optical. The same effect (LPF effect) as the light beam passed through is obtained.
　さらに、イメージセンサ２２の駆動範囲を段階的に切り替える（正方形軌跡の場合は一辺の長さを異ならせ、円形軌跡の場合は半径ｒを異ならせる）ことで、イメージセンサ２２によるＬＰＦ効果の強弱を段階的に切り替えることができる。つまり、正方形軌跡の一辺または円形軌跡の半径ｒを長くする（被写体光線が入射するイメージセンサ２２の検出色の異なる画素２２ａ（カラーフィルタＲ、Ｇ、Ｂ、Ｇ）に入射する画素２２ａの範囲を拡大する）ことでＬＰＦ効果が強くなり、一方、正方形軌跡の一辺または円形軌跡の半径ｒを短くする（被写体光線が入射するイメージセンサ２２の検出色の異なる画素２２ａ（カラーフィルタＲ、Ｇ、Ｂ、Ｇ）に入射する画素２２ａの範囲を縮小する）ことでＬＰＦ効果が弱くなる。表１に示すように、本実施形態では、イメージセンサ２２の駆動範囲ならびにＬＰＦ効果を「ＯＦＦ」、「小」、「中」、「大」の４段階で切り替えることができる。イメージセンサ２２の駆動範囲ならびにＬＰＦ効果が「ＯＦＦ」とは、イメージセンサ２２を駆動することなく、従ってＬＰＦ効果が得られない状態を意味する。
Figure JPOXMLDOC01-appb-T000001
 Further, by switching the driving range of the image sensor 22 stepwise (in the case of a square locus, the length of one side is varied, and in the case of a circular locus, the radius r is varied), the strength of the LPF effect by the image sensor 22 can be increased. It can be switched in stages. That is, the radius r of one side of the square locus or the circular locus is increased (the range of the pixel 22a incident on the pixel 22a (color filter R, G, B, G) having a different detection color of the image sensor 22 on which the subject light ray is incident). By enlarging, the LPF effect is strengthened, while the radius r of one side of the square locus or the circular locus is shortened (pixels 22a (color filters R, G, and B) having different detection colors of the image sensor 22 on which the subject ray is incident. , G)), the LPF effect is weakened. As shown in Table 1, in the present embodiment, the driving range of the image sensor 22 and the LPF effect can be switched in four stages of “OFF”, “small”, “medium”, and “large”. The driving range of the image sensor 22 and the LPF effect being “OFF” mean that the image sensor 22 is not driven and therefore the LPF effect cannot be obtained.
Figure JPOXMLDOC01-appb-T000001
　イメージセンサ２２の駆動範囲ならびにＬＰＦ効果の切り替えは、例えば、ローパスフィルタ操作スイッチ２７の手動操作により行う態様、あるいはＤＳＰ４０が種々の撮影条件パラメータに基づいて自動で行う態様が可能であり、その態様には自由度がある。 The switching of the driving range of the image sensor 22 and the LPF effect can be performed, for example, by a manual operation of the low-pass filter operation switch 27 or by the DSP 40 automatically based on various shooting condition parameters. Has a degree of freedom.
　図１、図２、図５に示すように、デジタルカメラ１０は、駆動用コイルＣ１、Ｃ２、Ｃ３に交流駆動信号を流すことで、像振れ補正装置５０を介してイメージセンサ２２を光軸直交平面内で駆動するイメージセンサ駆動回路（駆動信号生成部）６０を有している。このイメージセンサ駆動回路６０の動作全般はＤＳＰ４０によって制御される。 As shown in FIGS. 1, 2, and 5, the digital camera 10 causes the image sensor 22 to be orthogonal to the optical axis via the image blur correction device 50 by causing an AC drive signal to flow through the drive coils C 1, C 2, and C 3. An image sensor drive circuit (drive signal generation unit) 60 that drives in a plane is provided. The overall operation of the image sensor driving circuit 60 is controlled by the DSP 40.
　図５に示すように、イメージセンサ駆動回路６０は、加算部６１と、ゲイン部６２と、低周波駆動信号生成部６３と、高周波駆動信号生成部６４と、第１の重畳合成部６５と、コントローラ６６と、第２の重畳合成部６７とを有している。 As shown in FIG. 5, the image sensor driving circuit 60 includes an adding unit 61, a gain unit 62, a low frequency drive signal generating unit 63, a high frequency drive signal generating unit 64, a first superposition synthesis unit 65, A controller 66 and a second superimposing / combining unit 67 are provided.
　また、イメージセンサ駆動回路６０は、双方同時にオン状態とオフ状態が切り替わる第１スイッチＳＷ１と第２スイッチＳＷ２を有しており、第１スイッチＳＷ１と第２スイッチＳＷ２の双方がオン状態のときは、イメージセンサ２２を光軸直交平面内で微小振動させてＬＰＦ効果を得ることができ、第１スイッチＳＷ１と第２スイッチＳＷ２の双方がオフ状態のときは、イメージセンサ２２を光軸直交平面内で微小振動させてＬＰＦ効果を得ることができないようになっている。以下のイメージセンサ駆動回路６０の各構成要素６１～６７の説明は、第１スイッチＳＷ１と第２スイッチＳＷ２の双方がオン状態の場合である。 The image sensor drive circuit 60 has a first switch SW1 and a second switch SW2 that are simultaneously switched on and off. When both the first switch SW1 and the second switch SW2 are on, When the first switch SW1 and the second switch SW2 are both off, the image sensor 22 can be moved in the plane orthogonal to the optical axis. Thus, the LPF effect cannot be obtained by minute vibration. The following description of each of the components 61 to 67 of the image sensor driving circuit 60 is a case where both the first switch SW1 and the second switch SW2 are in the on state.
　加算部６１は、ジャイロセンサ２８が検出したボディ本体２０の光軸直交平面内の振れを示す振れ検出信号（制御目標信号）に加算処理を施す。 The addition unit 61 performs addition processing on a shake detection signal (control target signal) indicating the shake in the plane orthogonal to the optical axis of the body main body 20 detected by the gyro sensor 28.
　ゲイン部６２は、加算部６１が加算処理を施した振れ検出信号（制御目標信号）を増幅する。ゲイン部６２は、撮影レンズ３０とのレンズ通信で取得した該撮影レンズ３０の焦点距離情報に応じて、加算部６１が加算処理を施した振れ検出信号を増幅する。つまり、撮影レンズ３０の焦点距離情報は、ゲイン部６２が振れ検出信号を増幅するためのゲインに含まれる。 The gain unit 62 amplifies the shake detection signal (control target signal) subjected to the addition processing by the addition unit 61. The gain unit 62 amplifies the shake detection signal subjected to the addition process by the addition unit 61 in accordance with the focal length information of the photographing lens 30 acquired through lens communication with the photographing lens 30. That is, the focal length information of the photographic lens 30 is included in the gain for the gain unit 62 to amplify the shake detection signal.
　低周波駆動信号生成部６３は、所定の臨界周波数より低い駆動周波数の低周波駆動信号を生成する。低周波駆動信号生成部６３が生成する低周波駆動信号は、主として、イメージセンサ２２に静止摩擦状態でＬＰＦ動作（図４（Ａ）、（Ｂ））を行わせるための機能を有している。 The low frequency drive signal generation unit 63 generates a low frequency drive signal having a drive frequency lower than a predetermined critical frequency. The low frequency drive signal generated by the low frequency drive signal generation unit 63 mainly has a function for causing the image sensor 22 to perform the LPF operation (FIGS. 4A and 4B) in a static friction state. .
　高周波駆動信号生成部６４は、所定の臨界周波数より高い駆動周波数の高周波駆動信号を生成する。高周波駆動信号生成部６４が生成する高周波駆動信号は、主として、イメージセンサ２２に微小振動を与えることにより常に動摩擦状態にするディザ効果をもたらす機能を有している。 The high frequency drive signal generator 64 generates a high frequency drive signal having a drive frequency higher than a predetermined critical frequency. The high-frequency drive signal generated by the high-frequency drive signal generation unit 64 mainly has a function of providing a dither effect that always brings the image sensor 22 into a dynamic friction state by applying minute vibrations to the image sensor 22.
　ここで「所定の臨界周波数」は、例えば、５０Ｈｚ～５００Ｈｚの範囲内で設定することができるが、所定の臨界周波数より低い駆動周波数の低周波駆動信号と、所定の臨界周波数より高い駆動周波数の高周波駆動信号とを使い分けることができる限りにおいて、「所定の臨界周波数」をどのように定めるかには自由度がある。 Here, the “predetermined critical frequency” can be set within a range of 50 Hz to 500 Hz, for example, but a low frequency drive signal having a drive frequency lower than the predetermined critical frequency and a drive frequency higher than the predetermined critical frequency. As long as the high-frequency driving signal can be properly used, there is a degree of freedom in how to determine the “predetermined critical frequency”.
　第１の重畳合成部６５は、ジャイロセンサ２８から入力した後に加算部６１が加算処理を施してゲイン部６２が増幅した振れ検出信号（制御目標信号）に、低周波駆動信号生成部６３が生成した低周波駆動信号を重畳合成することにより、重畳制御目標信号を生成する。 The first superimposing / synthesizing unit 65 is generated by the low frequency drive signal generating unit 63 in the shake detection signal (control target signal) amplified by the gain unit 62 after being input from the gyro sensor 28 and added by the adding unit 61. The superposition control target signal is generated by superposing and synthesizing the low-frequency drive signal.
　コントローラ６６には、第１の重畳合成部６５が生成した重畳制御目標信号が入力される。コントローラ６６によるコントロールの方式としては例えばＰＩＤ制御などが考えられる。ＰＩＤ制御からはＰＷＭ制御で駆動用コイルＣ１、Ｃ２、Ｃ３を駆動するためのデューティ比が出力される。 The controller 66 receives the superposition control target signal generated by the first superposition synthesis unit 65. As a control method by the controller 66, for example, PID control can be considered. From the PID control, a duty ratio for driving the driving coils C1, C2, and C3 is output by PWM control.
　第２の重畳合成部６７は、第１の重畳合成部６５が生成した重畳制御目標信号（コントローラ６６が出力したデューティ比）に、高周波駆動信号生成部６４が生成した高周波駆動信号を重畳合成することにより、像振れ補正装置５０を介してイメージセンサ２２を光軸直交平面内で駆動するための駆動信号として、重畳駆動信号を生成する。 The second superposition synthesis unit 67 superimposes and synthesizes the high frequency drive signal generated by the high frequency drive signal generation unit 64 on the superposition control target signal generated by the first superposition synthesis unit 65 (duty ratio output by the controller 66). As a result, a superimposed drive signal is generated as a drive signal for driving the image sensor 22 in the plane orthogonal to the optical axis via the image blur correction device 50.
　第２の重畳合成部６７が生成した重畳駆動信号を駆動用コイルＣ１、Ｃ２、Ｃ３に流すことで、イメージセンサ２２を光軸直交平面内で駆動して、イメージセンサ２２に像振れ補正動作とＬＰＦ動作を実行させる。このように、重畳駆動信号に、イメージセンサ２２にＬＰＦ動作（図４（Ａ）、（Ｂ））を行わせるための低周波成分と、イメージセンサ２２に微小振動を与えることによりディザ効果をもたらす高周波成分とを含ませることで、イメージセンサ２２を高精度かつ柔軟に駆動制御することができる。 By causing the superimposition drive signal generated by the second superimposition synthesis unit 67 to flow through the driving coils C1, C2, and C3, the image sensor 22 is driven in the plane orthogonal to the optical axis, and the image sensor 22 performs an image blur correction operation. The LPF operation is executed. In this way, a low frequency component for causing the image sensor 22 to perform the LPF operation (FIGS. 4A and 4B) and a minute vibration are applied to the image sensor 22 in the superimposed drive signal, thereby providing a dither effect. By including the high frequency component, the image sensor 22 can be driven and controlled with high accuracy and flexibility.
　図６は、ＬＰＦ効果をオンにした場合とＬＰＦ効果をオフにした場合におけるイメージセンサ２２の光軸直交平面内での動きを示している。同図において、横軸は時間、縦軸は移動量を示しており、縦軸の移動量についてはＸ方向移動量とＹ方向移動量に分けて示している。同図に明らかなように、ＬＰＦ効果がオフの場合には、ジャイロセンサ２８から求められる制御目標信号に追従してイメージセンサ２２が駆動される。一方、ＬＰＦ効果がオンの場合には、ジャイロセンサ２８から求められる制御目標信号に、低周波駆動信号生成部６３が生成した低周波駆動信号と、高周波駆動信号生成部６４が生成した高周波駆動信号とが重畳されて、イメージセンサ２２が駆動される。 FIG. 6 shows the movement of the image sensor 22 in the plane orthogonal to the optical axis when the LPF effect is turned on and when the LPF effect is turned off. In the figure, the horizontal axis represents time, and the vertical axis represents the movement amount. The movement amount on the vertical axis is divided into an X-direction movement amount and a Y-direction movement amount. As can be seen from the figure, when the LPF effect is off, the image sensor 22 is driven following the control target signal obtained from the gyro sensor 28. On the other hand, when the LPF effect is on, the control target signal obtained from the gyro sensor 28 includes the low frequency drive signal generated by the low frequency drive signal generation unit 63 and the high frequency drive signal generated by the high frequency drive signal generation unit 64. Are superimposed and the image sensor 22 is driven.
　図７は、低周波駆動信号生成部６３と高周波駆動信号生成部６４が生成する低周波駆動信号Ｃｘと高周波駆動信号Ｄｘの信号波形を示している。 FIG. 7 shows signal waveforms of the low frequency drive signal Cx and the high frequency drive signal Dx generated by the low frequency drive signal generation unit 63 and the high frequency drive signal generation unit 64.
　続いて、イメージセンサ駆動回路６０の動作を制御するためのＤＳＰ４０の構成について説明する。図１に示すように、ＤＳＰ４０は、露光時間設定部４１と、周波数決定部４２と、デューティ比決定部４３とを有している。 Subsequently, the configuration of the DSP 40 for controlling the operation of the image sensor driving circuit 60 will be described. As shown in FIG. 1, the DSP 40 includes an exposure time setting unit 41, a frequency determination unit 42, and a duty ratio determination unit 43.
　露光時間設定部４１は、例えば、絞り３２のＦ値、シャッタ２１のシャッタ速度、ＩＳＯ感度、ＥＶ値などの各種パラメータにより、露光時間を設定する。 The exposure time setting unit 41 sets the exposure time according to various parameters such as the F value of the aperture 32, the shutter speed of the shutter 21, the ISO sensitivity, and the EV value.
　周波数決定部４２は、露光時間設定部４１が設定した露光時間に応じて、低周波駆動信号生成部６３が生成する低周波駆動信号の駆動周波数を決定する。 The frequency determination unit 42 determines the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 according to the exposure time set by the exposure time setting unit 41.
　デューティ比決定部４３は、周波数決定部４２が決定した低周波駆動信号の駆動周波数に応じて、高周波駆動信号生成部６４が生成する高周波駆動信号のデューティ比を決定する。 The duty ratio determination unit 43 determines the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64 according to the drive frequency of the low frequency drive signal determined by the frequency determination unit 42.
　ＤＳＰ４０は、露光時間設定部４１が設定した露光時間と、低周波駆動信号生成部６３が生成する低周波駆動信号の駆動周波数と、高周波駆動信号生成部６４が生成する高周波駆動信号のデューティ比とを対応付けたテーブルを保持しており、周波数決定部４２とデューティ比決定部４３がこのテーブルを参照して各種制御を実行できるようになっている。ＤＳＰ４０は、イメージセンサ２２によるＬＰＦ効果の大小設定に応じて異なる複数のテーブルを保持している。 The DSP 40 sets the exposure time set by the exposure time setting unit 41, the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63, and the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64. The frequency determination unit 42 and the duty ratio determination unit 43 can execute various controls with reference to this table. The DSP 40 holds a plurality of tables that differ depending on the setting of the LPF effect by the image sensor 22.
　表２は、ＤＳＰ４０が保持する、イメージセンサ２２によるＬＰＦ効果が「中」の場合のテーブルを示している。
　露光時間設定部４１が設定した露光時間が「Bulb-1s」の場合、周波数決定部４２は、低周波駆動信号生成部６３が生成する低周波駆動信号の駆動周波数を「１Ｈｚ(振幅は１画素相当)」に決定し、デューティ比決定部４３は、高周波駆動信号生成部６４が生成する高周波駆動信号のデューティ比を「３２０Ｈｚ(振幅はデューティ比３％相当)」に決定する。
　露光時間設定部４１が設定した露光時間が「1s-1/4s」の場合、周波数決定部４２は、低周波駆動信号生成部６３が生成する低周波駆動信号の駆動周波数を「４Ｈｚ(振幅は１画素相当)」に決定し、デューティ比決定部４３は、高周波駆動信号生成部６４が生成する高周波駆動信号のデューティ比を「３２０Ｈｚ(振幅はデューティ比４％相当)」に決定する。
　露光時間設定部４１が設定した露光時間が「1/4s-1/32s」の場合、周波数決定部４２は、低周波駆動信号生成部６３が生成する低周波駆動信号の駆動周波数を「３２Ｈｚ(振幅は１画素相当)」に決定し、デューティ比決定部４３は、高周波駆動信号生成部６４が生成する高周波駆動信号のデューティ比を「３２０Ｈｚ(振幅はデューティ比５％相当)」に決定する。
　露光時間設定部４１が設定した露光時間が「1/32s-1/8000s」の場合、周波数決定部４２とデューティ比決定部４３は何らの制御も行わない。
Figure JPOXMLDOC01-appb-T000002
 Table 2 shows a table when the LPF effect by the image sensor 22 held by the DSP 40 is “medium”.
When the exposure time set by the exposure time setting unit 41 is “Bulb-1s”, the frequency determination unit 42 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “1 Hz (amplitude is 1 pixel). The duty ratio determination unit 43 determines the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64 to be “320 Hz (amplitude is equivalent to a duty ratio of 3%)”.
When the exposure time set by the exposure time setting unit 41 is “1s-1 / 4s”, the frequency determination unit 42 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “4 Hz (the amplitude is The duty ratio determination unit 43 determines the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64 to be “320 Hz (amplitude is equivalent to a duty ratio of 4%)”.
When the exposure time set by the exposure time setting unit 41 is “1/4 s-1 / 32 s”, the frequency determination unit 42 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “32 Hz ( The duty ratio determination unit 43 determines the duty ratio of the high-frequency drive signal generated by the high-frequency drive signal generation unit 64 to be “320 Hz (amplitude is equivalent to a duty ratio of 5%)”.
When the exposure time set by the exposure time setting unit 41 is “1 / 32s-1 / 8000s”, the frequency determination unit 42 and the duty ratio determination unit 43 do not perform any control.
Figure JPOXMLDOC01-appb-T000002
　表３は、ＤＳＰ４０が保持する、イメージセンサ２２によるＬＰＦ効果が「大」の場合のテーブルを示している。
　露光時間設定部４１が設定した露光時間が「Bulb-1s」の場合、周波数決定部４２は、低周波駆動信号生成部６３が生成する低周波駆動信号の駆動周波数を「１Ｈｚ(振幅は１画素相当)」に決定し、デューティ比決定部４３は、高周波駆動信号生成部６４が生成する高周波駆動信号のデューティ比を「３２０Ｈｚ(振幅はデューティ比２％相当)」に決定する。
　露光時間設定部４１が設定した露光時間が「1s-1/4s」の場合、周波数決定部４２は、低周波駆動信号生成部６３が生成する低周波駆動信号の駆動周波数を「４Ｈｚ(振幅は１画素相当)」に決定し、デューティ比決定部４３は、高周波駆動信号生成部６４が生成する高周波駆動信号のデューティ比を「３２０Ｈｚ(振幅はデューティ比３％相当)」に決定する。
　露光時間設定部４１が設定した露光時間が「1/4s-1/32s」の場合、周波数決定部４２は、低周波駆動信号生成部６３が生成する低周波駆動信号の駆動周波数を「３２Ｈｚ(振幅は１画素相当)」に決定し、デューティ比決定部４３は、高周波駆動信号生成部６４が生成する高周波駆動信号のデューティ比を「３２０Ｈｚ(振幅はデューティ比４%相当)」に決定する。
　露光時間設定部４１が設定した露光時間が「1/32s-1/8000s」の場合、周波数決定部４２とデューティ比決定部４３は何らの制御も行わない。
Figure JPOXMLDOC01-appb-T000003
 Table 3 shows a table when the LPF effect by the image sensor 22 held by the DSP 40 is “large”.
When the exposure time set by the exposure time setting unit 41 is “Bulb-1s”, the frequency determination unit 42 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “1 Hz (amplitude is 1 pixel). The duty ratio determination unit 43 determines the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64 to be “320 Hz (the amplitude is equivalent to a duty ratio of 2%)”.
When the exposure time set by the exposure time setting unit 41 is “1s-1 / 4s”, the frequency determination unit 42 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “4 Hz (the amplitude is The duty ratio determination unit 43 determines the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64 to be “320 Hz (amplitude is equivalent to a duty ratio of 3%)”.
When the exposure time set by the exposure time setting unit 41 is “1/4 s-1 / 32 s”, the frequency determination unit 42 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “32 Hz ( The duty ratio determination unit 43 determines the duty ratio of the high frequency drive signal generated by the high frequency drive signal generation unit 64 to be “320 Hz (amplitude is equivalent to a duty ratio of 4%)”.
When the exposure time set by the exposure time setting unit 41 is “1 / 32s-1 / 8000s”, the frequency determination unit 42 and the duty ratio determination unit 43 do not perform any control.
Figure JPOXMLDOC01-appb-T000003
　低周波駆動信号の周波数が上がるほど正確な制御が難しくなる分、高周波駆動信号のデューティ比を上げて静止摩擦状態から動摩擦状態に変える。デューティ比が上がるほど音や振動は大きくなるが、露光秒時が短くなるのでユーザの不快感を抑えたまま制御性能を上げる効果がある。高周波駆動信号は画質に影響を及ぼさない十分微小な駆動になるように設定される。また振幅が大きいほど、制御器がより大きいデューティ比を算出するので、静止摩擦分を補償する高周波駆動信号の動きを相対的に小さくしても同等の追随能力を維持できるのでこれを小さくして雑音を抑えておく。 正確 As the frequency of the low frequency drive signal increases, accurate control becomes more difficult, and the duty ratio of the high frequency drive signal is increased to change from the static friction state to the dynamic friction state. As the duty ratio increases, sound and vibration increase, but since the exposure time is shortened, there is an effect of improving the control performance while suppressing user discomfort. The high-frequency drive signal is set so that the drive is sufficiently small without affecting the image quality. Also, the greater the amplitude, the larger the duty ratio is calculated by the controller, so even if the movement of the high-frequency drive signal that compensates for the static friction is relatively small, the same tracking ability can be maintained, so this should be reduced. Keep the noise down.
　図８はコントローラ６６の閉ループ特性を示している。高周波駆動信号はデューティ比に重畳される外乱となるので、制御器であまり圧縮されない周波数を選択する。具体的にはゲインが－１２ｄｂよりも小さい周波数を選択する。すなわち、高周波駆動信号生成部６４が生成する高周波駆動信号の駆動周波数は、制御器の閉ループ特性のゲインが－１２ｄＢ以下となるように設定することが好ましい。これにより、外乱の７５％以上が圧縮されずに重畳される。 FIG. 8 shows the closed loop characteristics of the controller 66. Since the high-frequency drive signal is a disturbance superimposed on the duty ratio, a frequency that is not much compressed by the controller is selected. Specifically, a frequency with a gain smaller than −12 db is selected. That is, it is preferable to set the drive frequency of the high frequency drive signal generated by the high frequency drive signal generation unit 64 so that the gain of the closed loop characteristic of the controller is −12 dB or less. Thereby, 75% or more of the disturbance is superimposed without being compressed.
　図９は、制御器の閉ループ特性のゲインが－１２ｄＢ以下となるような高周波駆動信号を重畳した重畳駆動信号によってイメージセンサ２２を駆動した場合における該イメージセンサ２２の光軸直交平面内での動きを示している。同図の例では、ジャイロセンサ２８による振れ検出信号の出力、すなわちボディ本体２０のブレによる外乱成分がゼロの場合（手振れ補正オフの場合）を想定している。 FIG. 9 shows the movement of the image sensor 22 in the plane orthogonal to the optical axis when the image sensor 22 is driven by a superimposed drive signal on which a high-frequency drive signal is superimposed so that the gain of the closed loop characteristic of the controller is −12 dB or less. Is shown. In the example shown in the figure, it is assumed that the output of the shake detection signal by the gyro sensor 28, that is, the case where the disturbance component due to the shake of the body body 20 is zero (when the shake correction is off).
＜第２実施形態＞
　図１０を参照して、本発明の第２実施形態に係るデジタルカメラ（撮影装置）１０'について説明する。このデジタルカメラ１０'は、図１に示した第１実施形態に係るデジタルカメラ１０において、周波数決定部４２とデューティ比決定部４３に代えて、第１の周波数決定部４５と第２の周波数決定部４６を設けた構成となっている。 Second Embodiment
With reference to FIG. 10, a digital camera (photographing apparatus) 10 ′ according to a second embodiment of the present invention will be described. This digital camera 10 ′ is different from the frequency determination unit 42 and the duty ratio determination unit 43 in the digital camera 10 according to the first embodiment shown in FIG. 1 in that the first frequency determination unit 45 and the second frequency determination are performed. The portion 46 is provided.
　第１の周波数決定部４５は、露光時間設定部４１が設定した露光時間に応じて、低周波駆動信号生成部６３が生成する低周波駆動信号の駆動周波数を決定する。 The first frequency determination unit 45 determines the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 according to the exposure time set by the exposure time setting unit 41.
　第２の周波数決定部４６は、第１の周波数決定部４５が決定した低周波駆動信号の駆動周波数に応じて、高周波駆動信号生成部６４が生成する高周波駆動信号の駆動周波数を決定する。 The second frequency determination unit 46 determines the drive frequency of the high-frequency drive signal generated by the high-frequency drive signal generation unit 64 according to the drive frequency of the low-frequency drive signal determined by the first frequency determination unit 45.
　ＤＳＰ４０は、露光時間設定部４１が設定した露光時間と、低周波駆動信号生成部６３が生成する低周波駆動信号の駆動周波数と、高周波駆動信号生成部６４が生成する高周波駆動信号の駆動周波数とを対応付けたテーブルを保持しており、第１の周波数決定部４５と第２の周波数決定部４６がこのテーブルを参照して各種制御を実行できるようになっている。 The DSP 40 has an exposure time set by the exposure time setting unit 41, a driving frequency of the low frequency driving signal generated by the low frequency driving signal generating unit 63, and a driving frequency of the high frequency driving signal generated by the high frequency driving signal generating unit 64. The first frequency determination unit 45 and the second frequency determination unit 46 can execute various controls with reference to this table.
　表４は、ＤＳＰ４０が保持するテーブルの一例を示している。
　露光時間設定部４１が設定した露光時間が「Bulb-1s」の場合、第１の周波数決定部４５は、低周波駆動信号生成部６３が生成する低周波駆動信号の駆動周波数を「１Ｈｚ(振幅は１画素相当)」に決定し、第２の周波数決定部４６は、高周波駆動信号生成部６４が生成する高周波駆動信号の駆動周波数を「１０Ｈｚ(振幅は１画素相当」に決定する。
　露光時間設定部４１が設定した露光時間が「1s-1/4s」の場合、第１の周波数決定部４５は、低周波駆動信号生成部６３が生成する低周波駆動信号の駆動周波数を「４Ｈｚ(振幅は１画素相当)」に決定し、第２の周波数決定部４６は、高周波駆動信号生成部６４が生成する高周波駆動信号の駆動周波数を「４０Ｈｚ(振幅は１画素相当」に決定する。
　露光時間設定部４１が設定した露光時間が「1/4s-1/32s」の場合、第１の周波数決定部４５は、低周波駆動信号生成部６３が生成する低周波駆動信号の駆動周波数を「３２Ｈｚ(振幅は１画素相当)」に決定し、第２の周波数決定部４６は、高周波駆動信号生成部６４が生成する高周波駆動信号の駆動周波数を「３２０Ｈｚ(振幅は１画素相当」に決定する。
　露光時間設定部４１が設定した露光時間が「1/32s-1/8000s」の場合、第１の周波数決定部４５と第２の周波数決定部４６は何らの制御も行わない。高周波駆動信号を低周波駆動信号の１０倍以上の周波数にすることで、静止摩擦を十分補償することができ、高周波駆動周波数を低く抑えることで雑音を抑えることができる。
Figure JPOXMLDOC01-appb-T000004
 Table 4 shows an example of a table held by the DSP 40.
When the exposure time set by the exposure time setting unit 41 is “Bulb-1s”, the first frequency determination unit 45 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “1 Hz (amplitude). The second frequency determination unit 46 determines the drive frequency of the high frequency drive signal generated by the high frequency drive signal generation unit 64 as “10 Hz (amplitude is equivalent to one pixel)”.
When the exposure time set by the exposure time setting unit 41 is “1s-1 / 4s”, the first frequency determination unit 45 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63 to “4 Hz”. (The amplitude is equivalent to one pixel) ”, and the second frequency determination unit 46 determines the drive frequency of the high frequency drive signal generated by the high frequency drive signal generation unit 64 to be“ 40 Hz (amplitude is equivalent to one pixel) ”.
When the exposure time set by the exposure time setting unit 41 is “1 / 4s−1 / 32s”, the first frequency determination unit 45 sets the drive frequency of the low frequency drive signal generated by the low frequency drive signal generation unit 63. The frequency determination unit 46 determines “32 Hz (amplitude is equivalent to one pixel)”, and the second frequency determination unit 46 determines the driving frequency of the high-frequency driving signal generated by the high-frequency driving signal generation unit 64 is “320 Hz (amplitude is equivalent to one pixel)”. To do.
When the exposure time set by the exposure time setting unit 41 is “1 / 32s−1 / 8000s”, the first frequency determination unit 45 and the second frequency determination unit 46 do not perform any control. By setting the high-frequency drive signal to a frequency 10 times or more that of the low-frequency drive signal, static friction can be sufficiently compensated, and noise can be suppressed by reducing the high-frequency drive frequency.
Figure JPOXMLDOC01-appb-T000004
＜第３実施形態＞
　図１１、図１２を参照して、本発明の第３実施形態に係るデジタルカメラ１０について説明する。図１１は、本発明の第３実施形態において、第２の重畳合成部６７が生成する重畳駆動信号に含まれる低周波駆動信号と高周波駆動信号、すなわち低周波駆動信号生成部６３と高周波駆動信号生成部６４が生成する低周波駆動信号Ｃｘと高周波駆動信号Ｄｘの信号波形を示している。図１２は、本発明の第３実施形態において、制御器の閉ループ特性のゲインが－１２ｄＢ以下となるような高周波駆動信号を重畳した重畳駆動信号によってイメージセンサ２２を駆動した場合における該イメージセンサ２２の光軸直交平面内での動きを示している。同図の例では、ジャイロセンサ２８による振れ検出信号の出力、すなわちボディ本体２０のブレによる外乱成分がゼロの場合（手振れ補正オフの場合）を想定している。 <Third Embodiment>
A digital camera 10 according to a third embodiment of the present invention will be described with reference to FIGS. FIG. 11 shows a low frequency drive signal and a high frequency drive signal included in the superimposed drive signal generated by the second superposition synthesis unit 67, that is, the low frequency drive signal generation unit 63 and the high frequency drive signal in the third embodiment of the present invention. The signal waveform of the low frequency drive signal Cx and the high frequency drive signal Dx which the production | generation part 64 produces | generates is shown. FIG. 12 shows the image sensor 22 when the image sensor 22 is driven by a superimposed drive signal on which a high-frequency drive signal is superimposed so that the gain of the closed-loop characteristic of the controller is −12 dB or less in the third embodiment of the present invention. The movement in the optical axis orthogonal plane is shown. In the example shown in the figure, it is assumed that the output of the shake detection signal by the gyro sensor 28, that is, the case where the disturbance component due to the shake of the body body 20 is zero (when the shake correction is off).
　この第３実施形態では、低周波駆動信号生成部６３が生成する低周波駆動信号Ｃｘの振幅に応じて、高周波駆動信号生成部６４が生成する高周波駆動信号Ｄｘの振幅を変更する。すなわち、低周波駆動信号生成部６３が生成した低周波駆動信号によるイメージセンサ（移動部材、振れ補正部材）２２の動きが相対的に大きいタイミングで、高周波駆動信号生成部６４が生成した高周波駆動信号によるイメージセンサ（移動部材、振れ補正部材）２２の動き（高周波駆動信号Ｄｘの振幅）が相対的に小さくなっている。逆に、低周波駆動信号生成部６３が生成した低周波駆動信号によるイメージセンサ（移動部材、振れ補正部材）２２の動きが相対的に小さいタイミングで、高周波駆動信号生成部６４が生成した高周波駆動信号によるイメージセンサ（移動部材、振れ補正部材）２２の動き（高周波駆動信号Ｄｘの振幅）が相対的に大きくなっている。 In the third embodiment, the amplitude of the high frequency drive signal Dx generated by the high frequency drive signal generation unit 64 is changed according to the amplitude of the low frequency drive signal Cx generated by the low frequency drive signal generation unit 63. That is, the high-frequency drive signal generated by the high-frequency drive signal generation unit 64 at a timing when the movement of the image sensor (moving member, shake correction member) 22 by the low-frequency drive signal generated by the low-frequency drive signal generation unit 63 is relatively large. The movement of the image sensor (moving member, shake correction member) 22 (the amplitude of the high-frequency drive signal Dx) is relatively small. Conversely, the high frequency drive generated by the high frequency drive signal generation unit 64 at a timing when the movement of the image sensor (moving member, shake correction member) 22 by the low frequency drive signal generated by the low frequency drive signal generation unit 63 is relatively small. The movement (the amplitude of the high-frequency drive signal Dx) of the image sensor (moving member, shake correction member) 22 by the signal is relatively large.
　低周波駆動信号の動きが大きい部分はすでに動摩擦状態なので、高周波駆動信号を重畳する必要がない。
　第１実施形態における低周波駆動信号Ｃｘと高周波駆動信号Ｄｘの振幅が一定の場合に、
Cx(t) = A * sinωt
Dx(t) = B * sinθt
だとすると、
Dx(t) = B * | sinωt | * sinθt
と置き換えたものが、この第３実施形態の図１１、図１２となる。
　これにより、制御性能を落とさず振動や音を低減する効果が得られる。 Since the portion where the movement of the low frequency drive signal is large is already in the dynamic friction state, it is not necessary to superimpose the high frequency drive signal.
When the amplitudes of the low-frequency drive signal Cx and the high-frequency drive signal Dx in the first embodiment are constant,
Cx (t) = A * sinωt
Dx (t) = B * sinθt
If so,
Dx (t) = B * | sinωt | * sinθt
FIG. 11 and FIG. 12 of the third embodiment are replaced with FIG.
Thereby, the effect of reducing vibration and sound without degrading the control performance can be obtained.
　このように、本実施形態のデジタルカメラ（撮影装置）１０、１０'によれば、低周波駆動信号生成部６３が、所定の臨界周波数より低い駆動周波数の低周波駆動信号を生成し、高周波駆動信号生成部６４が、所定の臨界周波数より高い駆動周波数の高周波駆動信号を生成し、第１の重畳合成部６５が、入力した制御目標信号に低周波駆動信号生成部６３が生成した低周波駆動信号を重畳合成することにより重畳制御目標信号を生成し、第２の重畳合成部６７が、第１の重畳合成部６５が生成した重畳制御目標信号に高周波駆動信号生成部６４が生成した高周波駆動信号を重畳合成することにより、駆動信号としての重畳駆動信号を生成する。これにより、イメージセンサ（移動部材、振れ補正部材）２２を高精度かつ柔軟に駆動制御するとともに、高周波騒音が発生してユーザに不快感を与えるのを防止することができる。 As described above, according to the digital cameras (photographing apparatuses) 10 and 10 ′ of the present embodiment, the low frequency drive signal generation unit 63 generates a low frequency drive signal having a drive frequency lower than a predetermined critical frequency, and performs high frequency drive. The signal generation unit 64 generates a high-frequency drive signal having a drive frequency higher than a predetermined critical frequency, and the first superposition synthesis unit 65 generates the low-frequency drive generated by the low-frequency drive signal generation unit 63 based on the input control target signal. The superposition control target signal is generated by superimposing the signals, and the second superposition synthesis unit 67 generates the superposition control target signal generated by the first superposition synthesis unit 65. The high frequency drive signal generated by the high frequency drive signal generation unit 64 A superimposed drive signal as a drive signal is generated by superimposing and synthesizing the signals. As a result, the image sensor (moving member, shake correcting member) 22 can be driven and controlled with high accuracy and flexibly, and high-frequency noise can be prevented from causing discomfort to the user.
　以上の実施形態では、イメージセンサ２２を「移動部材、振れ補正部材」として、このイメージセンサ２２を光軸直交平面内で駆動する態様を例示して説明したが、本発明はこれに限定されるものではない。例えば、撮影レンズ群（撮影光学系）３１の少なくとも一部をなすレンズ（光学要素）を「移動部材、振れ補正部材」として、このレンズ（光学要素）を撮影レンズ３０内に設けたボイスコイルモータ（駆動機構）によって光軸直交平面内で駆動する態様も可能である。あるいは、イメージセンサ２２と撮影レンズ群（撮影光学系）３１の少なくとも一部をなすレンズ（光学要素）の双方を「移動部材、振れ補正部材」として、これらを光軸直交平面内で駆動する態様も可能である。いずれの態様であっても、イメージセンサ２２上への被写体像の結像位置を変位させて像振れを補正するとともに、被写体光束をイメージセンサ２２の検出色の異なる複数の画素に入射させて光学的なローパスフィルタ効果を得ることができる。 In the above embodiment, the image sensor 22 is described as the “moving member, shake correction member”, and the mode in which the image sensor 22 is driven in the plane orthogonal to the optical axis has been described. However, the present invention is limited to this. It is not a thing. For example, a lens (optical element) forming at least a part of the photographic lens group (photographic optical system) 31 is a “moving member, shake correction member”, and this lens (optical element) is provided in the photographic lens 30. A mode of driving in a plane orthogonal to the optical axis by the (drive mechanism) is also possible. Alternatively, both the image sensor 22 and the lens (optical element) forming at least a part of the photographing lens group (photographing optical system) 31 are “moving members and shake correcting members”, and these are driven in an optical axis orthogonal plane. Is also possible. In any embodiment, the image blur is corrected by displacing the imaging position of the subject image on the image sensor 22, and the subject light flux is incident on a plurality of pixels having different detection colors of the image sensor 22 to optically. A typical low-pass filter effect can be obtained.
　以上の実施形態では、像振れ補正動作及びＬＰＦ動作を実行するために、像振れ補正装置（駆動機構）５０を介してイメージセンサ（移動部材、振れ補正部材）２２を光軸直交平面内で駆動する場合を例示して説明したが、イメージセンサ（移動部材、振れ補正部材）２２を駆動する方向はこれに限定されず、撮影光学系の光軸と異なる方向であればよい。 In the above embodiment, the image sensor (moving member, shake correction member) 22 is driven in the plane orthogonal to the optical axis via the image shake correction device (drive mechanism) 50 in order to execute the image shake correction operation and the LPF operation. However, the direction in which the image sensor (moving member, shake correction member) 22 is driven is not limited to this, and may be any direction different from the optical axis of the photographing optical system.
　以上の実施形態では、ＤＳＰ４０とイメージセンサ駆動回路６０を別々の構成要素（ブロック）として描いているが、これらを単一の構成要素（ブロック）として実現する態様も可能である。 In the above embodiment, the DSP 40 and the image sensor drive circuit 60 are drawn as separate components (blocks), but an aspect in which these are realized as a single component (block) is also possible.
　以上の実施形態では、像振れ補正装置（駆動機構）５０の構成として、固定支持基板５１に磁石Ｍ１、Ｍ２、Ｍ３及びヨークＹ１、Ｙ２、Ｙ３を固定し、可動ステージ５２に駆動用コイルＣ１、Ｃ２、Ｃ３を固定した場合を例示して説明したが、この位置関係を逆にして、可動ステージに磁石及びヨークを固定し、固定支持基板に駆動用コイルを固定する態様も可能である。 In the above embodiment, the image blur correction device (drive mechanism) 50 is configured such that the magnets M1, M2, M3 and the yokes Y1, Y2, Y3 are fixed to the fixed support substrate 51, and the drive coil C1, The case where C2 and C3 are fixed has been described as an example. However, it is also possible to reverse this positional relationship, fix the magnet and the yoke to the movable stage, and fix the driving coil to the fixed support substrate.
　以上の実施形態では、ボディ本体２０と撮影レンズ３０を着脱可能（レンズ交換可能）とする態様を例示して説明したが、ボディ本体２０と撮影レンズ３０を着脱不能（レンズ交換不能）とする態様も可能である。 In the above embodiment, the mode in which the body main body 20 and the photographic lens 30 are detachable (lens exchangeable) has been described as an example, but the mode in which the body main body 20 and the photographic lens 30 are not detachable (lens exchangeable) Is also possible.
　本発明の撮影装置及びその制御方法は、デジタルカメラ等の撮影装置及びその制御方法に用いて好適である。 The imaging apparatus and the control method thereof according to the present invention are suitable for use in an imaging apparatus such as a digital camera and the control method thereof.
１０　１０'　デジタルカメラ（撮影装置）
２０　ボディ本体
２１　シャッタ（撮影光学系）
２２　イメージセンサ（移動部材、振れ補正部材）
２２ａ　画素
Ｒ　Ｇ　Ｂ　カラーフィルタ
２３　絞り／シャッタ駆動回路
２４　ＬＣＤ
２５　画像メモリ
２６　撮影操作スイッチ
２７　ローパスフィルタ操作スイッチ
２８　ジャイロセンサ（振れ検出部）
３０　撮影レンズ
３１　撮影レンズ群（撮影光学系、移動部材、振れ補正部材）
３２　絞り（撮影光学系）
３３　通信用メモリ
４０　ＤＳＰ
４１　露光時間設定部
４２　周波数決定部
４３　デューティ比決定部
４５　第１の周波数決定部
４６　第２の周波数決定部
５０　像振れ補正装置（駆動機構）
５１　固定支持基板
５２　可動ステージ
Ｍ１　Ｍ２　Ｍ３　磁石
Ｙ１　Ｙ２　Ｙ３　ヨーク
Ｃ１　Ｃ２　Ｃ３　駆動用コイル
Ｈ１　Ｈ２　Ｈ３　ホールセンサ
６０　イメージセンサ駆動回路（駆動信号生成部）
６１　加算部
６２　ゲイン部
６３　低周波駆動信号生成部
６４　高周波駆動信号生成部
６５　第１の重畳合成部
６６　コントローラ
６７　第２の重畳合成部
ＳＷ１　第１スイッチ
ＳＷ２　第２スイッチ 10 10 'Digital camera (photographing device)
20 Body body 21 Shutter (shooting optical system)
22 Image sensor (moving member, shake correction member)
22a Pixel RGB color filter 23 Aperture / shutter drive circuit 24 LCD
25 Image memory 26 Shooting operation switch 27 Low-pass filter operation switch 28 Gyro sensor (shake detection unit)
30 Shooting lens 31 Shooting lens group (shooting optical system, moving member, shake correction member)
32 Aperture (Optical system)
33 Communication memory 40 DSP
41 Exposure time setting unit 42 Frequency determining unit 43 Duty ratio determining unit 45 First frequency determining unit 46 Second frequency determining unit 50 Image blur correction device (drive mechanism)
51 Fixed support substrate 52 Movable stage M1 M2 M3 Magnet Y1 Y2 Y3 Yoke C1 C2 C3 Driving coil H1 H2 H3 Hall sensor 60 Image sensor drive circuit (drive signal generator)
61 Adder 62 Gain unit 63 Low frequency drive signal generator 64 High frequency drive signal generator 65 First superposition synthesis unit 66 Controller 67 Second superposition synthesis unit SW1 First switch SW2 Second switch

Claims (14)

  1. 　撮影光学系により形成された被写体像を電気的な画素信号に変換するイメージセンサと、
    　前記撮影光学系の少なくとも一部をなす光学要素と前記イメージセンサの少なくとも一方を移動部材とし、この移動部材を前記撮影光学系の光軸と異なる方向に駆動することにより、被写体光束を前記イメージセンサの検出色の異なる複数の画素に入射させて、光学的なローパスフィルタ効果を得る駆動機構と、
    　前記駆動機構を介して前記移動部材を駆動するための駆動信号を生成する駆動信号生成部と、
    　を有する撮影装置において、
    　前記駆動信号生成部は、
    　所定の臨界周波数より低い駆動周波数の低周波駆動信号を生成する低周波駆動信号生成部と、
    　所定の臨界周波数より高い駆動周波数の高周波駆動信号を生成する高周波駆動信号生成部と、
    　入力した制御目標信号に前記低周波駆動信号生成部が生成した低周波駆動信号を重畳合成することにより重畳制御目標信号を生成する第１の重畳合成部と、
    　前記第１の重畳合成部が生成した重畳制御目標信号に前記高周波駆動信号生成部が生成した高周波駆動信号を重畳合成することにより、前記駆動信号としての重畳駆動信号を生成する第２の重畳合成部と、
    　を有することを特徴とする撮影装置。     An image sensor that converts a subject image formed by the photographing optical system into an electrical pixel signal;
    At least one of the optical element that forms at least a part of the photographing optical system and the image sensor is a moving member, and the moving member is driven in a direction different from the optical axis of the photographing optical system, so that the subject light flux is emitted from the image sensor. A drive mechanism for obtaining an optical low-pass filter effect by making it incident on a plurality of pixels having different detection colors;
    A drive signal generator for generating a drive signal for driving the moving member via the drive mechanism;
    In a photographing apparatus having
    The drive signal generator is
    A low frequency drive signal generating unit that generates a low frequency drive signal having a drive frequency lower than a predetermined critical frequency;
    A high-frequency drive signal generating unit that generates a high-frequency drive signal having a drive frequency higher than a predetermined critical frequency;
    A first superposition synthesis unit that generates a superposition control target signal by superposing and synthesizing the low frequency drive signal generated by the low frequency drive signal generation unit on the input control target signal;
    A second superposition synthesis that generates a superposition drive signal as the drive signal by superposing and synthesizing the high frequency drive signal generated by the high frequency drive signal generation unit on the superposition control target signal generated by the first superposition synthesis unit. And
    A photographing apparatus comprising:
  2. 　請求項１記載の撮影装置において、
    　露光時間を設定する露光時間設定部と、
    　前記露光時間設定部が設定した露光時間に応じて、前記低周波駆動信号生成部が生成する低周波駆動信号の駆動周波数を決定する周波数決定部と、
    　前記周波数決定部が決定した低周波駆動信号の駆動周波数に応じて、前記高周波駆動信号生成部が生成する高周波駆動信号のデューティ比を決定するデューティ比決定部と、をさらに有する撮影装置。     The imaging device according to claim 1,
    An exposure time setting section for setting the exposure time;
    In accordance with the exposure time set by the exposure time setting unit, a frequency determining unit that determines the driving frequency of the low frequency drive signal generated by the low frequency drive signal generating unit;
    An imaging apparatus, further comprising: a duty ratio determining unit that determines a duty ratio of a high-frequency driving signal generated by the high-frequency driving signal generating unit according to a driving frequency of the low-frequency driving signal determined by the frequency determining unit.
  3. 　請求項１記載の撮影装置において、
    　露光時間を設定する露光時間設定部と、
    　前記露光時間設定部が設定した露光時間に応じて、前記低周波駆動信号生成部が生成する低周波駆動信号の駆動周波数を決定する第１の周波数決定部と、
    　前記第１の周波数決定部が決定した低周波駆動信号の駆動周波数に応じて、前記高周波駆動信号生成部が生成する高周波駆動信号の駆動周波数を決定する第２の周波数決定部と、をさらに有する撮影装置。     The imaging device according to claim 1,
    An exposure time setting section for setting the exposure time;
    A first frequency determining unit that determines a driving frequency of a low-frequency driving signal generated by the low-frequency driving signal generating unit according to an exposure time set by the exposure time setting unit;
    A second frequency determining unit that determines a driving frequency of the high-frequency driving signal generated by the high-frequency driving signal generating unit according to the driving frequency of the low-frequency driving signal determined by the first frequency determining unit; Shooting device.
  4. 　請求項１ないし３のいずれか１項記載の撮影装置において、
    　前記高周波駆動信号生成部が生成する高周波駆動信号の駆動周波数は、制御器の閉ループ特性のゲインが－１２ｄＢ以下である撮影装置。     In the imaging device according to any one of claims 1 to 3,
    The imaging apparatus in which the high frequency drive signal generated by the high frequency drive signal generator has a closed loop characteristic gain of -12 dB or less.
  5. 　請求項１ないし４のいずれか１項記載の撮影装置において、
    　前記低周波駆動信号生成部が生成した低周波駆動信号による前記移動部材の動きが相対的に大きいタイミングで、前記高周波駆動信号生成部が生成した高周波駆動信号による前記移動部材の動きが相対的に小さい撮影装置。     The photographing apparatus according to any one of claims 1 to 4,
    The movement of the moving member due to the high-frequency drive signal generated by the high-frequency drive signal generation unit is relatively high when the movement of the moving member due to the low-frequency drive signal generated by the low-frequency drive signal generation unit is relatively large. Small shooting device.
  6. 　請求項１ないし５のいずれか１項記載の撮影装置において、
    　前記低周波駆動信号生成部が生成する低周波駆動信号の振幅に応じて、前記高周波駆動信号生成部が生成する高周波駆動信号の振幅を変更する撮影装置。     The photographing apparatus according to any one of claims 1 to 5,
    An imaging apparatus that changes an amplitude of a high-frequency drive signal generated by the high-frequency drive signal generation unit according to an amplitude of a low-frequency drive signal generated by the low-frequency drive signal generation unit.
  7. 　請求項１ないし６のいずれか１項記載の撮影装置において、
    　前記イメージセンサを搭載したボディ本体の振れを検出する振れ検出部をさらに有しており、
    　前記振れ検出部は、検出した振れ検出信号を前記制御目標信号として出力する撮影装置。     The photographing apparatus according to any one of claims 1 to 6,
    It further has a shake detection unit for detecting shake of the body body equipped with the image sensor,
    The shake detection unit outputs a detected shake detection signal as the control target signal.
  8. 　撮影光学系により形成された被写体像を電気的な画素信号に変換するイメージセンサと、前記撮影光学系の少なくとも一部をなす光学要素と前記イメージセンサの少なくとも一方を移動部材とし、この移動部材を前記撮影光学系の光軸と異なる方向に駆動することにより、被写体光束を前記イメージセンサの検出色の異なる複数の画素に入射させて、光学的なローパスフィルタ効果を得る駆動機構と、を有する撮影装置の制御方法において、
    　前記駆動機構を介して前記移動部材を駆動するための駆動信号を生成する駆動信号生成ステップを有し、
    　前記駆動信号生成ステップは、
    　所定の臨界周波数より低い駆動周波数の低周波駆動信号を生成する低周波駆動信号生成ステップと、
    　所定の臨界周波数より高い駆動周波数の高周波駆動信号を生成する高周波駆動信号生成ステップと、
    　入力した制御目標信号に前記低周波駆動信号生成ステップで生成した低周波駆動信号を重畳合成することにより重畳制御目標信号を生成する第１の重畳合成ステップと、
    　前記第１の重畳合成ステップで生成した重畳制御目標信号に前記高周波駆動信号生成ステップで生成した高周波駆動信号を重畳合成することにより、前記駆動信号としての重畳駆動信号を生成する第２の重畳合成ステップと、
    　を有することを特徴とする撮影装置の制御方法。     An image sensor that converts an object image formed by the photographing optical system into an electrical pixel signal, an optical element that forms at least a part of the photographing optical system, and at least one of the image sensor as a moving member. A driving mechanism that obtains an optical low-pass filter effect by causing a subject luminous flux to enter a plurality of pixels having different detection colors of the image sensor by driving in a direction different from the optical axis of the imaging optical system In the device control method,
    A drive signal generation step of generating a drive signal for driving the moving member via the drive mechanism;
    The drive signal generation step includes
    A low frequency drive signal generating step for generating a low frequency drive signal having a drive frequency lower than a predetermined critical frequency;
    A high-frequency drive signal generating step for generating a high-frequency drive signal having a drive frequency higher than a predetermined critical frequency;
    A first superimposition synthesis step of generating a superimposition control target signal by superimposing and synthesizing the low frequency drive signal generated in the low frequency drive signal generation step on the input control target signal;
    The second superposition synthesis that generates the superposition drive signal as the drive signal by superposing and synthesizing the high frequency drive signal generated in the high frequency drive signal generation step on the superposition control target signal generated in the first superposition synthesis step. Steps,
    A method for controlling an imaging apparatus, comprising:
  9. 　請求項８記載の撮影装置の制御方法において、
    　露光時間を設定する露光時間設定ステップと、
    　前記露光時間設定ステップで設定した露光時間に応じて、前記低周波駆動信号生成ステップで生成する低周波駆動信号の駆動周波数を決定する周波数決定ステップと、
    　前記周波数決定ステップで決定した低周波駆動信号の駆動周波数に応じて、前記高周波駆動信号生成ステップで生成する高周波駆動信号のデューティ比を決定するデューティ比決定ステップと、をさらに有する撮影装置の制御方法。     The method of controlling a photographing apparatus according to claim 8,
    An exposure time setting step for setting the exposure time;
    According to the exposure time set in the exposure time setting step, a frequency determination step for determining a drive frequency of the low frequency drive signal generated in the low frequency drive signal generation step;
    A method for controlling an imaging apparatus, further comprising: a duty ratio determining step for determining a duty ratio of the high frequency drive signal generated in the high frequency drive signal generation step according to the drive frequency of the low frequency drive signal determined in the frequency determination step .
  10. 　請求項８記載の撮影装置の制御方法において、
    　露光時間を設定する露光時間設定ステップと、
    　前記露光時間設定ステップで設定した露光時間に応じて、前記低周波駆動信号生成ステップで生成する低周波駆動信号の駆動周波数を決定する第１の周波数決定ステップと、
    　前記第１の周波数決定ステップで決定した低周波駆動信号の駆動周波数に応じて、前記高周波駆動信号生成ステップで生成する高周波駆動信号の駆動周波数を決定する第２の周波数決定ステップと、をさらに有する撮影装置の制御方法。     The method of controlling a photographing apparatus according to claim 8,
    An exposure time setting step for setting the exposure time;
    A first frequency determining step for determining a driving frequency of the low frequency driving signal generated in the low frequency driving signal generating step in accordance with the exposure time set in the exposure time setting step;
    A second frequency determining step for determining the driving frequency of the high-frequency driving signal generated in the high-frequency driving signal generating step according to the driving frequency of the low-frequency driving signal determined in the first frequency determining step. Control method of photographing apparatus.
  11. 　請求項８ないし１０のいずれか１項記載の撮影装置の制御方法において、
    　前記高周波駆動信号生成ステップで生成する高周波駆動信号の駆動周波数は、制御器の閉ループ特性のゲインが－１２ｄＢ以下である撮影装置の制御方法。     In the control method of the imaging device according to any one of claims 8 to 10,
    The driving method of the radio frequency driving signal generated in the high frequency driving signal generating step is a method for controlling an imaging apparatus in which the gain of the closed loop characteristic of the controller is -12 dB or less.
  12. 　請求項８ないし１１のいずれか１項記載の撮影装置の制御方法において、
    　前記低周波駆動信号生成ステップで生成した低周波駆動信号による前記移動部材の動きが相対的に大きいタイミングで、前記高周波駆動信号生成ステップで生成した高周波駆動信号による前記移動部材の動きが相対的に小さい撮影装置の制御方法。     The method of controlling a photographing apparatus according to any one of claims 8 to 11,
    The movement of the moving member due to the high frequency drive signal generated in the high frequency drive signal generation step is relatively high when the movement of the moving member due to the low frequency drive signal generated in the low frequency drive signal generation step is relatively large. Control method for small photographic equipment.
  13. 　請求項８ないし１２のいずれか１項記載の撮影装置の制御方法において、
    　前記低周波駆動信号生成ステップで生成する低周波駆動信号の振幅に応じて、前記高周波駆動信号生成ステップで生成する高周波駆動信号の振幅を変更する撮影装置の制御方法。     In the control method of the imaging device according to any one of claims 8 to 12,
    A method for controlling an imaging apparatus, wherein the amplitude of the high-frequency drive signal generated in the high-frequency drive signal generation step is changed according to the amplitude of the low-frequency drive signal generated in the low-frequency drive signal generation step.
  14. 　請求項８ないし１３のいずれか１項記載の撮影装置の制御方法において、
    　前記イメージセンサを搭載したボディ本体の振れを検出する振れ検出ステップをさらに有しており、
    　前記振れ検出ステップでは、検出した振れ検出信号を前記制御目標信号として出力する撮影装置の制御方法。     The method of controlling a photographing apparatus according to any one of claims 8 to 13,
    And further comprising a shake detection step of detecting a shake of the body body equipped with the image sensor,
    In the shake detection step, a method for controlling an imaging apparatus that outputs a detected shake detection signal as the control target signal.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09116910A (en) * 1995-10-17 1997-05-02 Canon Inc Image pickup device
JP2006101452A (en) * 2004-09-30 2006-04-13 Fuji Photo Film Co Ltd Imaging apparatus
JP2008176068A (en) * 2007-01-18 2008-07-31 Nikon Corp Blur correction device and optical device

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09116910A (en) * 1995-10-17 1997-05-02 Canon Inc Image pickup device
JP2006101452A (en) * 2004-09-30 2006-04-13 Fuji Photo Film Co Ltd Imaging apparatus
JP2008176068A (en) * 2007-01-18 2008-07-31 Nikon Corp Blur correction device and optical device

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