JP2013015571A - Imaging apparatus, program and shake correction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging apparatus capable of improving correction accuracy of shake correction by properly determining the influence of the gravity component.SOLUTION: An imaging apparatus includes: an imaging element which takes a subject image; detection means which detects an angular speed and an acceleration in an apparatus body; determination means which determines the posture of the apparatus body; calculation means in which the shake amount including the shake of an angle rotating a photographic optical axis and the shake of shift parallely moving the photographic optical axis based on the detected angle speed and acceleration is calculated by adjusting the gravity component according to the degree of influence of the gravity in the direction where the shake correction is performed in accordance with the determined posture; correction means which corrects the shake on the basis of the calculated shake amount.

Description

  The present invention relates to an imaging apparatus, a program, and a camera shake correction method that prevent deterioration of a captured image by correcting camera shake.

  2. Description of the Related Art As imaging devices such as digital cameras, imaging devices equipped with a mechanism for automatically determining the focus and exposure amount are in widespread use. In recent years, there has also been known an imaging apparatus that can suppress image quality deterioration of a captured image due to camera shake by correcting camera shake. The hand shake is a movement such as rotation of the image pickup apparatus caused by movement of a hand, an arm or the like that holds the image pickup apparatus, and is represented by a low frequency vibration of about 1 to 10 Hz. For this reason, in an imaging device that corrects camera shake, low-frequency vibrations of the imaging device caused by camera shake are detected, and the imaging element, the imaging lens, or a part of the lenses constituting the imaging lens are moved so as to cancel the vibration. This reduces the blurring of the image that appears in the captured image due to camera shake.

  In addition, in an imaging apparatus that prevents camera shake, angular blur due to rotation of the imaging apparatus is reduced as camera shake. For this reason, an angular velocity sensor is mounted and angular blur is detected by measuring the rotational speed of the imaging device. However, camera shake that occurs when shooting in macro mode with a high shooting magnification is controlled by the angular velocity sensor because blurring that shifts the imaging device in parallel (hereinafter referred to as shift blur) becomes more dominant than angular blur due to pressing of the release button or the like. It is difficult to accurately detect shift blur simply by measuring the rotational speed of the device.

  For these reasons, in recent years, there has been known an anti-vibration control device that is small in size and high in mobility and that performs highly accurate correction of translational blur using an angle sensor (see Patent Document 1). The image stabilization control apparatus includes a shake correction unit that corrects an image shake due to a shake, a first shake detection unit that detects an angular velocity of the shake, and a second shake detection unit that detects a shake by a method different from the first shake detection unit. And a correction value is obtained from the first signal based on the output of the first shake detection means and the second signal based on the output of the second shake detection means until the photographing operation of the image pickup apparatus to be image-stabilized is started. A device that calculates, corrects the output of the first shake detection means using the correction value, and drives the shake correction means based on the corrected output of the first shake detection means.

JP 2010-259591 A

  The anti-vibration control device described in Patent Document 1 considers both angle blur and shift blur when performing camera shake correction, but the gravity component must be taken into account when calculating the rotation radius of angle blur. There was a possibility that the accuracy of correction at the time would deteriorate.

  In other words, when performing camera shake correction, offset values that take gravity into account are often used.However, because camera shake correction is performed in a unified manner without regard to the camera posture, gravity may be excessive depending on the camera posture. There is a possibility that camera shake correction may be performed after evaluation, and in this case, there is a problem that the image quality of the captured image deteriorates.

  The present invention has been made in view of the above problems, and an object thereof is to provide an imaging apparatus, a program, and a camera shake correction method that can appropriately determine the influence of gravity components and improve the camera shake correction accuracy. To do.

  In order to achieve the above object, an imaging apparatus according to the present invention includes, as described in claim 1, an imaging element that captures a subject image, a detection unit that detects angular velocity and acceleration in the apparatus body, Based on the angular velocity and acceleration detected by the detecting means, the determining means for determining the posture, and the blur amount including the angular blur that rotates the photographing optical axis and the shift blur that translates the photographing optical axis are determined. According to the posture determined by the calculation method, the calculation unit that adjusts and calculates the gravity component according to the degree of the gravitational effect in the direction in which the camera shake correction is performed, and the camera shake is corrected based on the shake amount calculated by the calculation unit And correction means for performing.

  According to the first aspect of the present invention, the subject image is picked up by the image pickup device, the angular velocity and acceleration in the device main body are detected by the first detection means, and the posture of the device main body is determined by the determination means. . Further, the determining means determines the blur amount including angular blur for rotating the photographing optical axis and shift blur for translating the photographing optical axis based on the angular velocity and acceleration detected by the detecting means by the calculating means. The gravity component is adjusted according to the degree of gravitational force in the direction in which camera shake correction is performed according to the posture, and the shake is corrected based on the shake amount calculated by the calculation unit. The Thereby, by taking into consideration the posture of the apparatus main body, it is possible to appropriately determine the influence of the gravity component and to improve the correction accuracy of the camera shake correction.

  Moreover, in the imaging device according to the present invention, as described in claim 2, the determination unit determines in advance that the lateral inclination direction with the imaging direction of the imaging element of the device body as the central axis includes the horizontal direction. Determining that it is a landscape orientation when it is within a predetermined range, determining that it is a portrait orientation when the tilt direction is within a predetermined range including the direction of gravity, and When the determination means determines that the posture is the horizontal shooting posture, the blur amount is calculated without adjusting the gravity component in the horizontal direction, and the blur amount is calculated by adjusting the gravity component in the vertical direction. When the determination unit determines that the posture is the vertical shooting posture, the gravity component with respect to the horizontal direction is adjusted to calculate the blur amount, and the gravity component with respect to the vertical direction is not adjusted. It may be calculated the shake amount. Thereby, by taking into consideration the orientation of the apparatus main body, it is possible to appropriately determine the influence of the gravity component and improve the correction accuracy of camera shake correction.

  Moreover, in the imaging device according to the present invention, as described in claim 3, the determination unit further determines that the posture is a vertical shooting posture when the imaging direction is within a predetermined range including a gravity direction. The calculating unit may calculate the blur amount without adjusting the gravity component in the horizontal direction and the vertical direction when the determining unit determines that the posture is the vertical shooting posture. Thereby, by taking into consideration the imaging direction of the imaging apparatus, it is possible to appropriately determine the influence of the gravity component and improve the correction accuracy of the camera shake correction.

  Moreover, in the imaging device according to the present invention, as described in claim 4, when the imaging magnification at the time of imaging with the imaging element is less than a predetermined threshold, The blur amount may be calculated without adjusting the vertical gravity component. Accordingly, by taking into consideration the imaging magnification of the imaging apparatus, it is possible to appropriately determine the influence of the gravity component and improve the correction accuracy of the camera shake correction.

  In the imaging device according to the present invention, as described in claim 5, the calculation unit adjusts the gravity component in each of the horizontal direction and the vertical direction when the macro shooting mode is set. The blur amount may be calculated. Thereby, by taking into consideration the mode at the time of imaging, there is an effect that it is possible to appropriately determine the influence of the gravity component and improve the correction accuracy of the camera shake correction.

  In the imaging device according to the present invention, as described in claim 6, the determination unit determines that the posture of the device main body is the posture when the posture of the device body continues for a predetermined time. May be. Thereby, it is possible to improve the correction accuracy of the camera shake correction by appropriately determining the influence of the gravity component in consideration of the posture of the apparatus main body more precisely.

  In the image pickup apparatus according to the present invention, as described in claim 7, the correction unit corrects the camera shake by driving a shake correction lens that corrects the camera shake of the apparatus body when driven. You may do it. Thereby, there is an effect that it is possible to appropriately determine the influence of the gravity component and improve the correction accuracy of the camera shake correction.

  On the other hand, in order to achieve the above object, the program according to claim 8 is a program executed in a computer including an image pickup device that picks up a subject image and a detection unit that detects angular velocity and acceleration in the apparatus main body. Then, the computer is configured to determine the attitude of the apparatus main body, and based on the angular velocity and acceleration detected by the detection means, the angle blur that rotates the photographing optical axis and the shift blur that translates the photographing optical axis. A calculation unit that calculates and calculates a shake amount that includes a gravity component in accordance with a degree of influence of gravity in a direction in which camera shake correction is performed according to the posture determined by the determination unit; This is a program for functioning as a correction unit that corrects camera shake based on the shake amount.

  Therefore, according to the program described in claim 8, since the computer can be operated in the same manner as in the invention described in claim 1, the posture of the apparatus main body is taken into consideration as in the invention described in claim 1. Thus, it is possible to appropriately determine the influence of the gravity component and improve the correction accuracy of the camera shake correction.

  In order to achieve the above object, a camera shake correction method according to claim 9 is a camera shake correction method in an image pickup apparatus including an image pickup element that picks up a subject image and a detection unit that detects angular velocity and acceleration in the apparatus main body. The method includes a determination step for determining the attitude of the apparatus main body, an angular blur that rotates the photographing optical axis based on the angular velocity and acceleration detected by the detection means, and a shift blur that translates the photographing optical axis. The amount of shake to be calculated is calculated by adjusting the gravity component according to the degree of gravity in the direction in which camera shake correction is performed according to the posture determined in the determination step, and calculated by the calculation step And a correction step of correcting camera shake based on the amount of shake.

  Therefore, according to the camera shake correction method according to the ninth aspect, since it can operate in the same manner as the invention according to the first aspect, the posture of the measure main body is taken into consideration as in the first aspect. Thus, it is possible to appropriately determine the influence of the gravity component and improve the correction accuracy of the camera shake correction.

  According to the present invention, it is possible to appropriately determine the influence of the gravity component and improve the correction accuracy of the camera shake correction.

It is a figure which shows the external appearance of the imaging device which concerns on embodiment, (A) is a top view, (B) is a front view, (C) is a rear view. It is a block diagram which shows the structure of the imaging device which concerns on embodiment. It is the schematic for demonstrating the angle blurring in the imaging device which concerns on embodiment. It is the schematic for demonstrating the shift blur in the imaging device which concerns on embodiment. It is a block diagram which shows the structure of the principal part relevant to the blurring correction process in the imaging device which concerns on 1st Embodiment. It is a flowchart which shows the flow of a process by the blurring correction process program in the imaging device which concerns on 1st Embodiment. It is a block diagram which shows the structure of the principal part relevant to the blurring correction process in the imaging device which concerns on 2nd Embodiment. It is a flowchart which shows the flow of a process by the blurring correction process program in the imaging device which concerns on 2nd Embodiment.

[First Embodiment]
Hereinafter, the imaging device 1 according to the first embodiment will be described in detail with reference to the accompanying drawings.

  1A and 1B are diagrams illustrating an appearance of an imaging apparatus 1 according to the present embodiment. FIG. 1A is a top view, FIG. 1B is a front view, and FIG. 1C is a rear view. FIG. 2 is a block diagram illustrating a configuration of the imaging apparatus 1 according to the present embodiment.

  As shown in FIG. 1, the imaging apparatus 1 has a housing 2 in which various electronic devices used for imaging are housed. An optical imaging system 3 including a plurality of lenses and a strobe 4 that emits light are provided on the front surface of the housing 2. Further, on the rear surface of the housing 2, a display unit 5 having an LCD (Liquid Crystal Display) and the like, and a menu operation unit 6A through which setting instructions are input by a user operation are provided. On the other hand, a release button 6B for inputting a shooting instruction or the like by a user operation, a power button 6C for inputting a power ON / OFF switching instruction by a user operation, and a mode switching instruction by a user operation are provided on the upper surface of the housing 2. A mode switching button 6D is provided. Hereinafter, the menu operation unit 6A, the release button 6B, the power button 6C, and the mode switching button 6D are collectively referred to as the operation unit 6.

  On the display unit 5, an image with a small number of pixels to be captured prior to capturing a still image is displayed as a through image, whereby the display unit 5 functions as a viewfinder. Further, the display unit 5 displays an image stored in a storage device (not shown) such as a memory card, or displays an operation menu, a setting menu, or the like according to the operation of the operation unit 6 by the user.

  The mode switched by the mode switching button 6D is a shooting mode for shooting, a macro shooting mode for shooting in macro mode, a playback mode for displaying an existing shot image on the display unit 5, a setting mode for performing various settings, and the like. is there. The macro mode is a mode in which a subject is photographed close to the subject, and is a mode in which a depth of field is set such that a nearby object is in focus. When the imaging device 1 is set to the macro mode, the subject depth at the time of shooting by the imaging device 1 is set within a predetermined range.

  As shown in FIG. 1, in the imaging apparatus 1, the horizontal direction of the housing 2 is the x direction and the vertical direction is the y direction.

  As shown in FIG. 2, the imaging apparatus 1 includes the imaging optical system 3, the imaging element 12, the first blur correction unit 13A, the second blur correction unit 13B, the angular velocity sensor 14, the acceleration sensor 15, and an AFE (Analog Front End). ) Detection circuit 16, AE / AWB (Automatic Exposure / Automatic White Balance) detection circuit 17, AFE 31, A / D converter 32, DSP (Digital Signal Processor) 33, image processing unit 34, memory 35, CPU (Central Processing Unit) 37).

  The imaging optical system 3 includes a lens 21, a diaphragm 22, a shake correction lens 23, and the like. The lens 21 is a lens provided so as to be movable along the optical axis L during zooming and focus adjustment. Although one lens 21 is shown in FIG. 2 for the sake of simplicity, the lens 21 includes a plurality of lenses, and includes a zooming lens driven during zooming, a focusing lens driven during focus adjustment, and the like. . The diaphragm 22 has an opening formed by a plurality of diaphragm blades on the optical axis L, and adjusts the exposure amount by moving the position of the diaphragm blade and adjusting the size of the opening.

  The shake correction lens 23 is provided so as to be movable in a direction perpendicular to the optical axis L, and is moved in a direction to cancel the shake when a shake (angle shake or shift shake) occurs in the imaging apparatus 1. The blur correction lens 23 is driven by an actuator 24 including a voice coil motor (VCM) and a stepping motor. Note that the movement direction and amount of movement of the blur correction lens 23 are controlled by the first blur correction unit 13A and the second blur correction unit 13B.

  The imaging element 12 is, for example, a CCD type imaging element, and is arranged with the imaging surface facing the imaging optical system 3. A plurality of pixels are provided in a predetermined arrangement on the imaging surface, and an image of the subject is captured by photoelectrically converting light incident from the subject for each pixel. An imaging signal output from the imaging device 12 is input to the AFE 31, and noise is removed and amplified by correlated double sampling. In this way, noise is removed by the AFE 31, and the amplified imaging signal is converted into digital image data by the A / D converter 31 and input to the DSP 33.

  The DSP 33 functions as an image quality correction processing circuit that performs signal processing such as gradation correction processing and gamma correction processing on input image data, and a compression / decompression processing circuit that compresses / decompresses image data in a predetermined format such as JPEG. The image processing unit 34 receives image data that has been subjected to various types of correction processing by the DSP 33, and further performs image processing such as contour enhancement processing. Image data that has been subjected to image processing by the image processing unit 34 is stored in the memory 35 or displayed on the display unit 5.

  The AF detection circuit 16 is a circuit that detects a focal length based on image data output from the DSP 33, and outputs an evaluation value obtained by extracting and integrating a high-frequency component from a predetermined AF detection area in the image data. Then, based on the evaluation value, the focusing lens (lens 21) of the imaging optical system 3 is moved along the optical axis L so that the contrast in the AF detection area is maximized, thereby automatically performing focusing. .

  The AE / AWB detection circuit 17 detects whether or not the white balance is appropriate for shooting based on the image data output from the DSP 33, and detects an exposure amount appropriate for shooting. Then, the size of the aperture of the diaphragm 22 and the speed of the electronic shutter of the image sensor 12 are adjusted so that the exposure amount is appropriate.

  The first blur correction unit 13A and the second blur correction unit 13B calculate and correct camera shake generated in the imaging device 1 based on the angular velocity ω generated by the rotation of the imaging device 1 and the translational acceleration Acc1 generated by the parallel movement. . There are two types of camera shake calculated by the first blur correction unit 13A and the second blur correction unit 13B: angular blur due to rotation of the optical axis L and shift blur due to parallel movement in a plane perpendicular to the optical axis L. . Further, when the shake correction units 13A and 13B calculate the angular shake and the shift shake based on the angular velocity ω and the translational acceleration Acc1, respectively, the overall shake amount δ is calculated based on these.

  The blur amount δ is input to an actuator 54 described later, and the actuator 54 drives the blur correction lens 23 so as to cancel the input blur amount δ. Therefore, in the imaging apparatus 1, both the angle blur and the shift blur are corrected by the movement of the blur correction lens 23. Note that the blur correction units 13A and 13B acquire the angular velocity ω from the output value of the angular velocity sensor 14 and acquire the translational acceleration Acc1 from the output value of the acceleration sensor 15.

  The CPU 37 comprehensively controls each unit of the above-described imaging device 1 in accordance with a user operation via the operation unit 6. For example, when the release button is pressed halfway, the CPU 37 performs automatic focus adjustment by the AF detection circuit 16 and also automatically adjusts the exposure amount by the AE / AWB detection circuit 17. Further, the CPU 37 executes a shake correction processing program to be described later when the imaging device 1 is set to the shooting mode.

  Hereinafter, an aspect of camera shake correction by the imaging apparatus 1 will be described. The imaging device 1 calculates the angle blur and the shift blur by the blur correction units 13A and 13B as described above.

  FIG. 3 is a schematic diagram for explaining angle blurring in the imaging apparatus 1 according to the present embodiment. As shown in FIG. 3, the angle θ is an angle at which the optical axis L rotates around the rotation center C, and the rotation radius R is, for example, the length from the rotation center C to the angular velocity sensor 14. The angle θ is calculated by integrating the angular velocity ω, and the turning radius R is calculated based on the translational acceleration Acc1 generated by shift blur and the angular velocity ω, as will be described later.

  FIG. 4 is a schematic diagram for explaining shift blur in the imaging apparatus 1 according to the present embodiment. As shown in FIG. 4, the shift blur is a blur due to the parallel movement of the imaging device 1 in a plane perpendicular to the optical axis L, and the translational blur amount Y due to the shift blur is Y = R depending on the angle θ and the rotation radius R.・ Represented by the relationship of θ.

  In the imaging apparatus 1 according to the present embodiment, the shake amount is calculated by adding the angle shake and the shift shake for each of the x direction and the y direction shown in FIG. 1, and the camera shake correction is performed for each of the x direction and the y direction. I do.

From the translation blur amount Y and angle θ at the position of the principal point of the imaging optical system, the shake δ generated on the imaging surface from the focal length f of the imaging optical system and the imaging magnification β can be obtained by the following equation (1).
δ = (1 + β) fθ + βY (1)

Here, the relationship between the translational blur amount Y at the principal point position of the imaging optical system 3, the angle θ, and the rotation radius R when the rotation center C is defined can be expressed by the following equation (2), and the acceleration signal is differentiated once. The relationship between the translational velocity V, the angular velocity ω, and the rotation radius R when the rotation center C is determined can be expressed by equation (3).
Y = Rθ (2)
V = Rω ……………… (3)

Therefore, in the imaging apparatus 1 of the present embodiment, in the direction of gravity, camera shake correction is performed on the shake amount δ that is rewritten from Equation (1) as in Equation (4) below.
δ = (1 + β) fθ + βRθ (4)

  That is, in the equation (4), when the shift blur is obtained, the translational blur amount Y obtained directly by the acceleration sensor 15 is not used, but the rotational radius R obtained by the equation (2) or the equation (3) is once obtained. A rotation radius R, an angle θ, zoom, focus, and an imaging magnification β obtained thereby are used.

  Here, the acceleration sensor 15 is disposed at the lens principal point position of the imaging optical system 3, and the rotation radius R is equal to the distance from the rotation center C to the lens principal point position of the imaging optical system 3. The value Y can be obtained by second-order integration of the accelerometer signal. Therefore, the reason why the shift blur correction is performed using the equation (4), although the shift blur correction may be performed using the equation (1), will be described below. .

  Now, when the angle θ is input, the acceleration sensor 15 also detects the variation of the gravity component due to the inclination. In a range where the angle θ is not large, the gravitational acceleration (output by the acceleration sensor 15) output due to gravity fluctuation is proportional to the angle θ.

  Further, the result obtained by multiplying the angle θ by the rotation radius R is a translation blur amount Y (output from the acceleration sensor 15), and the acceleration due to the shift blur obtained by second-order differentiation of the translation blur amount Y is output from the acceleration sensor 15.

  Furthermore, noise is also superimposed on the output of the acceleration sensor 15. The types of noise include constant noise regardless of frequency and noise related to frequency. Here, the noise is not dependent on frequency and is treated as noise proportional to the angle θ.

  The sum of the acceleration due to the gravitational acceleration and the shift blur appears in the output of the acceleration sensor 15, and this is second-order integrated to obtain the translation blur amount Y.

右辺の第１項は加速度出力と重力加速度出力の項であり、第２項はノイズ項である。 Now, assuming that the gravitational acceleration proportional term is G, the radius of rotation is R, the noise proportional term is k, and the angular frequency is ω, the signal detection system can be expressed by the following equation (5).

The first term on the right side is a term for acceleration output and gravity acceleration output, and the second term is a noise term.

Here, both the acceleration output and the gravitational acceleration output are related to the phase of the angle θ, and noise is not related to the phase of the angle θ, so the right side of the equation (5) is divided into two terms. However, if the phase of each term is ignored for simplification, the following equation (6) is obtained.

  In other words, the displacement of shift blur is dominated by gravitational acceleration and noise on the low frequency side at each frequency where the equation (7) equation (each frequency at which the result of equation (6) becomes zero) holds. Accurate shift blur can be measured only with.

  On the other hand, the reliability of the acceleration signal is higher on the higher frequency side than this frequency.

  Now, the hand shake band is from 1 Hz to 10 Hz, and since it is already a band affected by gravitational acceleration and noise, shift blur cannot be detected using the acceleration sensor 15.

  Therefore, in the imaging apparatus 1 according to the present embodiment, when performing camera shake correction in the horizontal direction (a direction perpendicular to the gravity direction) that is not significantly affected by gravity, Equation (1) is used to correct the camera shake correction in the gravity direction. In performing, the equation (4) is used in consideration of detecting the translational blur amount Y using a reliable band of the acceleration sensor 15.

  FIG. 5 is a block diagram illustrating a configuration of a main part related to the shake correction processing of the imaging apparatus 1 according to the present embodiment. As shown in FIG. 5, the imaging apparatus 1 according to the present embodiment includes a first shake correction unit 13 </ b> A that performs camera shake correction using the equation (1), and performs the above-described camera shake correction. The second camera shake correction unit 13B that performs camera shake correction using the equation (4) is provided, and the camera shake correction is performed while switching to one of the camera shake correction units depending on whether the target direction is the direction of gravity. The imaging apparatus 1 according to the present embodiment includes the first shake correction unit 13A and the second shake correction unit 13B in each direction in order to perform the above-described camera shake correction in each of the x direction and the y direction. However, FIG. 5 shows only one block in the x direction or the y direction.

  In addition, as illustrated in FIG. 5, the imaging device 1 includes a switching unit 40 that determines and switches whether to take acceleration into account according to the posture of the imaging device 1. The angular velocity sensor 14, the switching unit 40 that inputs the acceleration signal and the acceleration signal from the acceleration sensor 15, and the shake correction unit 13 </ b> A calculate and correct the shake amount in consideration of the gravity, and the shake correction unit 13 </ b> B takes the gravity component into account. Without correcting, the blur amount is calculated and corrected. In addition, adding a gravity component means adjusting a gravity component using said (4) Formula.

  An output signal from the angular velocity sensor 14 (hereinafter referred to as an angular velocity signal) and an output signal from the acceleration sensor 15 (hereinafter referred to as an acceleration signal) are input to the switching unit 40. The switching unit 40 determines the gravitational direction of the imaging device 1 based on the acceleration signal, and determines the posture of the imaging device 1 based on the determination result. Then, the switching unit 40 determines the attitude of the imaging device 1, and outputs an angular velocity signal and an acceleration signal to the first blur correction unit 13A or outputs to the second blur correction unit 13B based on the determination result. To decide. The first blur correction unit 13A or the second blur correction unit 13B that receives the angular velocity signal and the acceleration signal calculates the blur amount, and controls the moving direction and the moving amount of the correction lens 23 based on the calculated blur amount. To do.

  First, the blur amount calculation procedure by the first blur correction unit 13A that calculates the blur amount in consideration of the gravity component will be described. Calculate the amount of shake with the gravitational component added. The blur correction unit 13A includes a band pass filter (BPF) 41, an A / D converter 42, high pass filters (HPF) 43 and 46, a phase correction circuit 44, and an integration circuit 45 in order to calculate the amount of change in angular velocity. In order to calculate the amount of change in acceleration, a low pass filter (LPF) 47, an A / D converter 48, an HPF 49, a phase correction circuit 50, and an integration circuit 51 are provided. In order to calculate and correct the amount, a rotation radius calculation unit 52, a shake amount calculation unit 53, and an actuator 54 are provided.

  Further, the blur correction unit 13B calculates a change amount of the angular velocity in order to calculate a band pass filter (BPF) 41, an A / D converter 42, high pass filters (HPF) 43 and 46, a phase correction circuit 44, and an integration circuit 45. And a low-pass filter (LPF) 47, an A / D converter 48, a phase correction circuit 50, and an integration circuit 51 for calculating the amount of change in acceleration. In order to calculate and correct the amount, a blur amount calculation unit 53 and an actuator 54 are provided.

  The angular velocity signal input to the first blur correction unit 13A is input to the BPF 41. Among the output signals of the angular velocity sensor 14, the component in the frequency band (for example, about 1 to 10 Hz) of the angle θ generated by the camera shake correction is A / D. Input to the converter 42. The A / D converter 42 converts the input angular velocity signal in a predetermined frequency band into a digital signal and inputs the digital signal to the HPF 43. The HPF 43 removes the DC component of the angular velocity signal. The angular velocity signal from which the DC component has been cut is input to the phase compensation circuit 44, and after the phase is adjusted, it is output as the angular velocity ω. The angular velocity ω output from the phase compensation circuit 44 is input to the integration circuit 45 and the turning radius calculation unit 52. The integration circuit 45 integrates the angular velocity ω input from the phase compensation circuit 44 and calculates the angle θ by removing the DC component by the HPF 46. The angle θ thus calculated is input to the shake amount calculation unit 53.

On the other hand, an output signal from the acceleration sensor 15 (hereinafter referred to as an acceleration signal) is input to the LPF 47 to remove noise, and is converted into a digital signal by the A / D converter 48 and input to the HPF 49. The HPF 49 is a filter that removes an acceleration component due to gravity, and the cut-off frequency fc is about 10 m / s ² . The translational acceleration Acc1 from which the gravitational acceleration is removed by the HPF 49 is input to the phase compensation circuit 50.

  The phase compensation circuit 50 adjusts the phase of the translational acceleration Acc1 input from the HPF 49 and inputs it to the integration circuit 51. The integrating circuit 51 calculates the translational velocity V due to shift blur by integrating the input translational acceleration Acc1. The translational velocity V due to shift blur calculated by the integration circuit 51 is input to the turning radius calculation unit 52.

  The turning radius calculation unit 52 calculates the turning radius R based on the angle θ generated in the imaging device 1 based on the angular velocity ω input from the phase compensation circuit 44 and the translation speed V input from the integration circuit 51. Specifically, the turning radius calculation unit 52 calculates the turning radius R by dividing the translation speed V by the angular speed ω (R = V / ω). The rotation radius R calculated by the rotation radius calculation unit 52 is input to the shake amount calculation unit 53.

  The shake amount calculation unit 53 acquires the angle θ from the HPF 46 and the rotation radius R from the rotation radius calculation unit 52. Further, the blur amount calculation unit 53 acquires the imaging magnification β and the focal length f from the CPU 37. The shake amount calculation unit 53 calculates the shake amount (δ = (1 + β) fθ + βRθ) from the acquired angle θ, rotation radius R, imaging magnification β, and focal length f. At this time, the shake amount calculation unit 53 corrects the value of the input rotation radius R to a gain-corrected value as the rotation radius R based on the sensitivity of the acceleration sensor 15. In the expression of the blur amount δ, “(1 + β) fθ” is the blur amount of angle blur, and “βRθ” is the blur amount of shift blur. The actuator 54 drives the blur correction lens 23 so that the blur amount δ calculated by the blur amount calculation unit 53 is canceled. As a result, camera shake (blur amount δ) is corrected.

  Next, calculation of the shake amount by the second shake correction unit 13B that does not take gravity components into account will be described. The angular velocity signal input to the first blur correction unit 13B is input to the BPF 41, and the component of the frequency band (for example, about 1 to 10 Hz) of the angle blur angle θ generated by the camera shake correction is output from the angular velocity sensor 14. It is input to the A / D converter 42. The A / D converter 42 converts the input angular velocity signal in a predetermined frequency band into a digital signal and inputs the digital signal to the HPF 43.

  The HPF 43 removes the DC component of the angular velocity signal. The angular velocity signal from which the DC component has been cut is input to the phase compensation circuit 44, and after the phase is adjusted, it is output as the angular velocity ω. The angular velocity ω output from the phase compensation circuit 44 is input to the integration circuit 45. The integration circuit 45 integrates the angular velocity ω input from the phase compensation circuit 44 and calculates the angle θ by removing the DC component by the HPF 46. The angle θ thus calculated is input to the shake amount calculation unit 53.

  On the other hand, an output signal from the acceleration sensor 15 (hereinafter referred to as an acceleration signal) is input to the LPF 47 to remove noise, and is converted into a digital signal by the A / D converter 48 and input to the phase compensation circuit 50.

  The phase compensation circuit 50 adjusts the phase of the translational acceleration Acc1 input from the A / D converter 48 and inputs it to the integration circuit 51. The integrating circuit 51 calculates the translational velocity V due to shift blur by integrating the input translational acceleration Acc1. The translational speed V due to shift blur calculated by the integration circuit 51 is input to the blur amount calculation unit 53.

  The shake amount calculation unit 53 acquires the angle θ from the HPF 46, and the shift blur translation speed V from the integration circuit 51. Further, the blur amount calculation unit 53 acquires the imaging magnification β and the focal length f from the CPU 37. The shake amount calculation unit 53 calculates a shake amount (δ = (1 + β) fθ + βY) from the acquired angle θ, translational shake amount Y, imaging magnification β, and focal length f. In the expression of the blur amount δ, “(1 + β) fθ” is the blur amount of angle blur, and “βRθ” is the blur amount of shift blur. The actuator 54 drives the blur correction lens 23 so that the blur amount δ calculated by the blur amount calculation unit 53 is canceled. As a result, camera shake (blur amount δ) is corrected.

  The imaging device 1 configured as described above uses the rotation radius R calculated by the rotation radius calculation unit 52, and the blur amount calculation unit 53 calculates the blur amount with the gravitational component added. The imaging apparatus 1 can correct camera shake more accurately regardless of the posture of the imaging apparatus 1.

  Here, the imaging apparatus 1 according to the present embodiment executes the shake correction processing program every elapse of a predetermined time while the imaging mode is set. First, the operation of the imaging apparatus 1 when executing the shake correction processing program will be described with reference to FIG. FIG. 6 is a flowchart showing the flow of processing of the shake correction processing program executed by the CPU 37 when the shooting mode is set, and the program is stored in the memory 35 in advance. The blur correction processing program may be stored in a recording medium such as a memory card, and installed in the memory 35 by being stored in the memory 35 from the recording medium.

  First, in step S101, the CPU 37 determines whether or not the imaging device 1 is set to the macro mode. The on / off state of the macro mode is preset by the user via the operation unit 6 and stored in the memory 35 in advance.

  If it is determined in step S101 that the macro mode is not set, in step S103, the CPU 37 determines whether or not the magnification is 0.2 or more. The magnification at this time is a relative value of the size of the subject on the photographed image when the same size as the actual size of the subject is 1.

  If it is determined in step S101 that the macro mode is set, and if it is determined in step S103 that the magnification is 0.2 or more, the amount of blurring of the captured image due to camera shake is large. It is desirable to add a gravity component to the calculation of the shake amount in the X direction and the Y direction of 1. In step S105, the CPU 37 performs shake correction in the X direction by adding the gravity component by the first shake correction unit 13A. . In step S107, the CPU 37 performs shake correction in the Y direction by adding the gravity component to the first shake correction unit 13A, and ends the shake correction processing program.

  If it is determined in step S105 that the magnification is less than 0.2, in step S109, the CPU 37 acquires information on the posture of the imaging device 1. At this time, the CPU 37 may determine the posture of the imaging device 1 based on the acceleration signal.

  In step S <b> 111, the CPU 37 determines whether or not the orientation of the imaging device 1 is landscape. At this time, the CPU 37 determines that the orientation of the imaging device 1 is landscape when the X direction of the imaging device 1 is perpendicular to the direction of gravity.

  If it is determined in step S111 that the orientation of the imaging device 1 is horizontal, in step S113, the CPU 37 causes the second shake correction unit 13B to determine the gravity component because the X direction of the imaging device 1 is the horizontal direction. The camera shake correction in the X direction is performed without consideration. In step S115, since the Y direction of the imaging apparatus 1 is the gravity direction, the CPU 37 corrects the camera shake in the Y direction by adding the gravity component, and ends the shake correction processing program. To do.

  If it is determined in step S111 that the orientation of the imaging device 1 is not horizontal, in step S117, the CPU 37 determines whether the orientation of the imaging device 1 is vertical in step S123. At this time, the CPU 37 determines that the orientation of the imaging device 1 is vertical when the Y direction of the imaging device 1 matches the gravity direction.

  When it is determined in step S117 that the imaging device 1 is in the vertical orientation, in step S119, the CPU 37 adds the gravity component to the first shake correction unit 13A because the X direction of the imaging device 1 is the gravity direction. Then, camera shake correction in the X direction is performed. In step S121, since the Y direction of the imaging device 1 is the horizontal direction, the CPU 37 performs hand shake correction in the Y direction without adding the gravitational component by the second shake correction unit 13B, and ends the shake correction processing program. To do.

  If it is determined in step S117 that the orientation of the imaging device 1 is not vertical, in step S123, the CPU 37 determines whether the orientation of the imaging device 1 is horizontal. At this time, the CPU 37 determines that the orientation of the imaging device 1 is horizontal when the normal direction of the XY plane of the imaging device 1 matches the gravity direction.

  When it is determined in step S123 that the orientation of the imaging device 1 is horizontal, in step S125, the CPU 37 adds the gravity component to the second shake correction unit 13B because the X direction of the imaging device 1 is the horizontal direction. Without camera shake correction in the X direction. In step S127, since the Y direction of the imaging apparatus 1 is also the horizontal direction, the CPU 37 performs camera shake correction in the Y direction without adding the gravitational component by the second shake correction unit 13B. Exit.

  When it is determined in step S123 that the orientation of the imaging device 1 is not horizontal, it is conceivable that the orientation of the imaging device 1 is oblique with respect to the horizontal direction. Therefore, in step S128, the CPU 37 adjusts the cutoff frequency used in the HPF 49 based on the inclination angle of the imaging direction of the imaging device 1 assumed from the acceleration signal with respect to the horizontal direction.

  In step S129, the CPU 37 corrects the camera shake in the X direction by changing the offset value in the HPF 49 by the first blur correction unit 13A. In step S131, the CPU 37 changes the offset value in the HPF 49 by using the first shake correction unit 13A, performs camera shake correction in the X direction, and ends the shake correction processing program.

  In this manner, the imaging apparatus 1 according to the present embodiment determines the attitude of the apparatus body, and based on the detected angular velocity and acceleration, the angle blur that rotates the photographing optical axis and the shift blur that translates the photographing optical axis. Is calculated by adjusting the gravitational component according to the degree of the gravitational effect for which the camera shake correction is performed according to the determined posture, and the blur is corrected based on the calculated blur amount. Thereby, there is an effect that it is possible to appropriately determine the influence of the gravity component and improve the correction accuracy of the camera shake correction.

[Second Embodiment]
Hereinafter, an imaging apparatus 1A according to the second embodiment will be described in detail with reference to the accompanying drawings. In addition, since the imaging apparatus 1A according to the second embodiment has the configuration illustrated in FIGS. 1 and 2, similarly to the imaging apparatus 1 according to the first embodiment, redundant description regarding the configuration is omitted. .

  FIG. 7 is a block diagram illustrating a configuration of a main part related to the blur correction process in the imaging apparatus 1A according to the present embodiment. In addition, the same code | symbol is attached | subjected to the structure same as FIG. 5, and the description is abbreviate | omitted.

  As illustrated in FIG. 7, the imaging device 1A is different from the imaging device 1 according to the first embodiment in that the imaging device 1A includes a timer unit 55. When the timer unit 55 receives a start instruction from the switching unit 40, the timer unit 55 starts measuring the timer time. When the timer unit 55 receives a reset instruction from the switching unit 40, the timer unit 55 resets the timer time to 0 and starts counting again. When the timer time request instruction is received, the timer time being measured is transmitted to the switching unit 40.

  Next, a description will be given based on a shake correction processing program showing a routine of shake correction processing in the imaging apparatus 1A according to the present embodiment. The imaging apparatus 1A executes the blur correction processing program every predetermined time while the imaging mode is set.

  With reference to FIG. 8, the execution process of the CPU 37 when executing the shake correction process program will be described. FIG. 8 is a flowchart showing the flow of processing of the shake correction processing program executed by the CPU 37 of the imaging apparatus 1A. The shake correction processing program is also stored in the memory 35 in advance. The blur correction processing program may be stored in a recording medium such as a memory card, and installed in the memory 35 by being stored in the memory 35 from the recording medium.

  First, in step S201, the CPU 37 starts a timer by causing the switching unit 40 to transmit a start instruction to the timer unit 55. Based on the timer time of this timer, it is determined whether or not the posture of the imaging apparatus 1A is maintained for a certain period of time.

  Next, in step S203, the CPU 37 determines whether or not the imaging apparatus 1A is set to the macro mode in the same procedure as in step S101.

  If it is determined in step S203 that the macro mode is not set, in step S205, the CPU 37 determines whether the magnification is 0.2 or more in the same procedure as in step S103.

  If it is determined in step S203 that the macro mode is set, or if it is determined in step S205 that the magnification is 0.2 or more, the amount of blurring of the captured image due to camera shake is large. In the x direction and the y direction of 1A, it is desirable to add a gravity component to the calculation of the shake amount. In step S207, the CPU 37 sets the first shake correction unit 13A in the x direction in the same procedure as in step S207. Thus, the first shake correction unit 13A performs camera shake correction in the x direction in consideration of the gravity component. In step S209, the CPU 37 sets the first shake correction unit 13A in the y direction, and the first shake correction unit 13A performs shake correction in the y direction by taking the gravity component into account. Exit.

  If it is determined in step S205 that the magnification is less than 0.2, in step S211, the CPU 37 acquires the posture information of the imaging apparatus 1A and stores it in the memory 35 in the same manner as in step S109. Remember.

  In step S213, the CPU 37 determines whether or not the attitude of the imaging device 1A has been changed. At this time, the CPU 37 determines whether or not the orientation has been changed by comparing the orientation of the imaging device 1A stored in the previous step S211 with the orientation of the imaging device 1A stored in the current step S207.

  If it is determined in step S213 that the posture of the imaging apparatus 1A has been changed, in step S215, the CPU 37 determines whether the new posture after the change is continued for a predetermined time, The timer is restarted by transmitting a reset instruction to 55, and the process proceeds to step S203.

  If it is determined in step S213 that the orientation of the imaging device 1A has not been changed, in step S217, the CPU 37 determines whether or not the timer time is equal to or greater than a predetermined value. At this time, the CPU 37 acquires the timer time by causing the switching unit 40 to transmit a timer time request instruction to the timer unit 55 and acquiring the timer time from the timer unit 55. Then, the CPU 37 determines whether or not the acquired timer time is a predetermined value or more. Information indicating the predetermined value is set in advance and stored in the memory 35.

  If it is determined in step S217 that the timer time is less than the predetermined value, the CPU 37 assumes that the posture of the imaging device 1A has not continued for a certain period of time, and proceeds to step S203.

  If it is determined in step S217 that the timer time is equal to or greater than the predetermined value, the CPU 37 performs blur correction processing in each of the x direction and the y direction, assuming that the attitude of the imaging device 1A has continued for a certain period of time. That is, the CPU 37 performs steps S219 to S241 (corresponding to steps S111 to S131) and ends the shake correction processing program.

  In this way, the imaging apparatus 1A according to the present embodiment determines the attitude of the apparatus body, and based on the detected angular velocity and acceleration, the angle blur that rotates the photographing optical axis and the shift blur that translates the photographing optical axis. Is calculated by adjusting the gravitational component according to the degree of the gravitational effect for which the camera shake correction is performed according to the determined posture, and the blur is corrected based on the calculated blur amount. Thereby, there is an effect that it is possible to appropriately determine the influence of the gravity component and improve the correction accuracy of the camera shake correction.

  In addition, the imaging apparatus 1A according to the present embodiment considers the attitude of the apparatus main body more precisely by determining that the attitude of the apparatus main body is the attitude only when the attitude of the apparatus main body continues for a predetermined time or more. Thus, it is possible to appropriately determine the influence of the gravity component and improve the correction accuracy of the camera shake correction.

  Note that the imaging apparatus 1 according to the present embodiment describes an example in which the imaging optical system 3 includes the shake correction lens 23 and the shake correction lens 23 is moved in a plane perpendicular to the optical axis L to correct camera shake. However, it is not limited to this. For example, camera shake correction can also be performed by moving the image sensor 12 with respect to the optical axis L of the imaging optical system 3. The imaging apparatus 1 according to the present embodiment is also suitable for an imaging apparatus that performs camera shake correction by moving the imaging element 12 in this way.

  In the present embodiment, the example in which the image sensor 12 is a CCD image sensor has been described. However, the present invention is not limited to this, and a CMOS image sensor may be used.

  DESCRIPTION OF SYMBOLS 1 ... Imaging device, 2 ... Housing | casing, 3 ... Optical imaging system, 4 ... Strobe, 5 ... Display part, 6 ... Operation part, 6A ... Menu operation part, 6B ... Release button, 6C ... Power button, 6D ... Mode switching Buttons 12, imaging devices 13 A, 13 B blur correction units 14 angular velocity sensors 15 acceleration sensors 16 AF detection circuits 17 AE / AWB detection circuits 21 lenses 22 apertures 23 blurs Correction lens, 31 ... AFE, 32, 42, 52 ... A / D converter, 33 ... DSP, 34 ... Image processing unit, 35 ... Memory, 36 ... Display unit, 37 ... CPU, 38 ... Operating unit, 40 ... Switch 41, BPF, 42, A / D converter, 43, 46, 49 ... HPF, 44 ... phase compensation circuit, 45 ... integration circuit, 47 ... LPF, 48, 50 ... phase compensation circuit, 57, 51 ... integration Circuit, 52 ... turning radius Out portion, 53 ... shake amount calculation unit, 54 ... actuator.

Claims (9)

An image sensor for capturing a subject image;
Detecting means for detecting angular velocity and acceleration in the apparatus body;
Determination means for determining the posture of the apparatus body;
Based on the angular velocity and acceleration detected by the detection means, a blur amount including an angular blur that rotates the photographing optical axis and a shift blur that translates the photographing optical axis is determined according to the posture determined by the determination means. Calculating means for adjusting and calculating a gravity component according to the degree of the influence of gravity in the direction in which camera shake correction is performed;
Correction means for correcting camera shake based on the shake amount calculated by the calculation means;
An imaging apparatus comprising: The determination means determines that the horizontal shooting posture is in the horizontal shooting direction when the horizontal inclination direction centering on the imaging direction of the imaging element of the apparatus main body is within a predetermined range including the horizontal direction, and the inclination When the direction is within a predetermined range including the direction of gravity, it is determined that the posture is vertical shooting,
The calculating means calculates the blur amount without adjusting the gravitational component with respect to the horizontal direction and adjusts the gravitational component with respect to the vertical direction when the determining means determines that the posture is horizontal shooting. And calculating the shake amount by adjusting the gravity component with respect to the horizontal direction, and calculating the blur amount with respect to the vertical direction. The imaging apparatus according to claim 1, wherein the blur amount is calculated without adjusting the image. The determination means further determines that the shooting direction is a vertical shooting posture when the imaging direction is within a predetermined range including a gravity direction,
The imaging device according to claim 2, wherein the calculating unit calculates the blur amount without adjusting the gravity component in the horizontal direction and the vertical direction when the determination unit determines that the posture is the vertical shooting posture. The calculation unit calculates the blur amount without adjusting the gravity component in the horizontal direction and the vertical direction when an imaging magnification at the time of imaging with the imaging element is less than a predetermined threshold. Item 4. The imaging device according to any one of Items 2 and 3. 5. The imaging according to claim 2, wherein, when the macro imaging mode is set, the calculation unit calculates the blur amount by adjusting the gravity components in the horizontal direction and the vertical direction. 6. apparatus. The imaging device according to any one of claims 1 to 5, wherein the determination unit determines that the posture of the apparatus main body is the posture when the posture of the device main body continues for a predetermined time or more. The imaging apparatus according to claim 1, wherein the correction unit corrects the camera shake by driving a camera shake correction lens that corrects a camera shake of the apparatus main body when driven. A program executed in a computer including an image sensor that captures a subject image and a detection unit that detects angular velocity and acceleration in the apparatus body,
The computer,
Determination means for determining the posture of the apparatus body;
Based on the angular velocity and acceleration detected by the detection means, a blur amount including an angular blur that rotates the photographing optical axis and a shift blur that translates the photographing optical axis is determined according to the posture determined by the determination means. Calculating means for adjusting and calculating a gravity component according to the degree of the influence of gravity in the direction in which camera shake correction is performed;
Correction means for correcting camera shake based on the shake amount calculated by the calculation means;
Program to function as. An image sensor for capturing a subject image;
A camera shake correction method in an imaging apparatus including a detection unit that detects angular velocity and acceleration in the apparatus body,
A determination step for determining the posture of the apparatus body;
Based on the angular velocity and acceleration detected by the detection means, the amount of blur including angular blur that rotates the photographing optical axis and shift blur that translates the photographing optical axis is determined according to the posture determined by the determination step. A calculation step of adjusting and calculating a gravity component according to the degree of the influence of gravity in the direction in which camera shake correction is performed;
A correction step of correcting camera shake based on the blur amount calculated by the calculation step;
A camera shake correction method.

Images