JP5168381B2 - Imaging device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily perform excellent photographing free from an image blur due to a camera-shake, and to effectively correct a blur when the camera-shake occurs. <P>SOLUTION: An imaging apparatus is equipped with: blur correction elements 21X and 21Y for generating gradation of a refractive index in a layer in accordance with applied voltage; a zoom lens unit 210 formed by arranging the blur correction elements on a photographing optical axis; an imaging element 73 for imaging an object image formed on an imaging surface by the zoom lens unit; angular velocity sensors 108 and 109 for detecting the blur amount of the produced blur; a blur correction amount calculating part 245 for calculating a blur correction amount in accordance with the blur amount detected by the angular velocity sensors; a blur correction element X direction driving part 215 and a blur correction element Y direction driving part 216 for applying voltage to the blur correction elements; and a camera control part 241 for controlling the blur correction element X direction driving part and the blur correction element Y direction driving part so as to suppress an image blur on the imaging surface of the imaging element 73 according to the correction amount calculated by the blur correction amount calculating part. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention relates to ZoSo location shooting with shake correction element formed of the optical crystal or the optical material.

  When shooting with a still camera handheld, when using a long focal length lens, macro photography, or a dark subject, image blur due to camera shake, posture blur, or subject movement (moving subject blur) may be noticeable. is there. Such image blur can be prevented to some extent by making the lens brighter, increasing the imaging sensitivity, setting the shutter speed faster, and learning the photographer, but there are limitations.

  In particular, since video cameras frequently use camera work and zoom, there is a problem that when camera movement and camera shake are intense, it becomes difficult to view due to image blur and screen shake, and various camera shake correction devices have been proposed.

  In such a camera shake correction apparatus, in the optical correction method, an image blur is corrected by mechanically moving an optical system such as a lens in accordance with a detected shake amount (see, for example, Patent Document 1).

  By the way, an optical material capable of changing the refractive index has been reported as an example of an optical material (electro-optic crystal). A new operating principle (space charge control mode) that induces a gradient of refractive index by injecting current into a 40 mm square electro-optic crystal made of KTN (potassium niobate tantalate), which was previously considered an insulator. ), The scanning efficiency (scanning angle of light generated when a voltage of 1 kv is applied to a crystal having a length of 1 cm and a thickness of 1 mm) is 12 degrees, which is 80 times higher than that of a conventional EO beam scanner. Development of an ultra-compact and ultra-fast EO beam scanner with high efficiency has been reported.

  A KTN crystal, which is an example of an electro-optic crystal, is a transparent optical crystal composed of potassium (K), tantalum (Ta), niobium (Nb) and oxygen (O), and was first synthesized in the 1950s and 60s. It has been known that the electro-optic effect (Kerr effect) is extremely large. However, crystal growth is difficult and practical use has been hindered until now.

In 2003, a successful production of a large crystal made of KTN was reported by performing precise temperature control, and a practical size of 40 mm square was achieved. Since the electro-optic coefficient representing the magnitude of the electro-optic effect of the KTN crystal is 600 pm / V or more, it reaches 20 times (in the case of an electric field of 60 V / mm or more), such as lithium niobate (LiNbO ₃ ), which is a conventional material. It has been announced that the drive voltage can be reduced to 1/10 for optical switches and the like by improving the size and drive voltage of the electro-optic crystal element (NTT presentation materials, NTT Photonics Laboratories).

In May 2006, we discovered the phenomenon that light can be bent freely using KTN crystals (potassium niobate tantalate, KTa _(1-X) Nb _(X) 0 ₃ ). An ultra-compact and ultra-fast EO (E1 electro-opt1c = electro-optic) beam scanner has been developed that has 80 times the scanning efficiency (May 18, 2006, the aforementioned NTT press release).

JP 62-47012 A

  However, Patent Document 1 employs a method in which the correction shift lens in the optical system is moved eccentrically in the vertical and horizontal directions perpendicular to the optical axis. Therefore, the variable angle range is narrow, and the eccentricity is increased as the correction angle is increased. There was a problem that the change in aberration was large.

  Further, in order to insert the above-described electro-optic crystal into the optical system and use it for correcting the optical axis, it is necessary to bend the two axes, but this has not been realized yet.

  Further, such a camera shake correction device is provided with a discriminating means for discriminating image blur caused by intentional camera work such as panning and tilting operations in moving image shooting and image blur caused by camera shake, and thereby image blur caused by camera shake. Only, and the swing back phenomenon at the time of pan / tilt operation is reduced, but the process of discriminating between camera shake and pan / tilt and the process of correcting shake back are complicated, and There is a problem that camera shake correction is not sufficiently performed if the discrimination is wrong.

  In addition to blur correction, there are also proposals that allow users to perform pan / tilt drive and fine adjustment of the optical axis in addition to blur correction. In conventional optical correction devices such as the image sensor shift type, there is a problem that the angle range in which the shooting direction can be moved is narrow, and aberrations increase as the angle increases. Even if it can be used, it has been difficult to use for driving panning and tilting driving for moving image shooting.

The present invention has been made in view of the above. The purpose of the present invention is to reduce the occurrence of camera shake during panning / tilting operations in moving image shooting and the like, and to shake the blur correction device during panning / tilting operations. Able to avoid reversal, etc., and even if camera shake occurs during pan / tilt operation, it can also perform sufficient shake correction, can configure a simple drive mechanism, and realize a small and thin mounted device it is to provide an imaging equipment that can.

( 1 ) The present invention provides an optical material that generates a gradation of refractive index in a layer according to an applied voltage, a photographing optical system in which the optical material is arranged on a photographing optical axis, and imaging by the photographing optical system. Imaging means for picking up a subject image formed on a surface, detection means for detecting a panning amount or a tilt amount according to a panning operation or a tilting operation, a driving means for applying a voltage to the optical material, and the detection means according pirn amount or amount of tilt detected by, an imaging apparatus Ru and control means for controlling said drive means to move the object image formed on the imaging surface of the imaging means, the optical material Has a first electrode formed on an opposing surface in a first direction orthogonal to the direction of the imaging optical axis, and the first electrode tilts the imaging optical axis according to a voltage applied to the first electrode. With the image stabilizer According to the voltage applied to the second electrode, a second electrode is formed on the opposing surface of the second direction perpendicular to the direction of the photographing optical axis and perpendicular to the first direction. A blur correction element including a second blur correction element that tilts the photographing optical axis is configured .

According to the present invention, it is possible to reduce the occurrence of camera shake during panning / tilting operations in moving image shooting, etc., and to avoid shakeback of the shake correction device during panning / tilting operations, and during panning / tilting operations. Even when camera shake occurs, sufficient blur correction can be performed, a simple drive mechanism can be configured, and a small and thin mounted device can be realized.

FIG. 4A is a perspective view illustrating an example of a shake correction element. FIG. 6B is a schematic diagram illustrating a state of a refractive index distribution generated when a voltage waveform is applied to the blur correction element 11. (C) is a graph showing the thickness direction of the blur correction element 11 and the change in refractive index. (D) Examples of the shake correcting device, the electric field of the KTN crystal and lithium niobate (LiNbO ₃₎ - is a graph showing characteristics of the refractive index change. (A) is a figure which shows the 2nd structural example of a blurring correction element, (B) is a figure which shows the 3rd structural example of a blurring correction element. (A) is a figure which shows the 4th structural example of a blurring correction element, (B) is a figure which shows the 5th structural example of a blurring correction element, (C) is a 6th structure of a blurring correction element. It is a figure which shows an example. (A) is a figure which shows the structure of the zoom lens unit of an optical camera-shake correction apparatus, (B) is a figure which shows the state in which camera shake was added, (C) is a camera shake in a camera. It is a figure which shows the state which carried out camera shake correction | amendment in the state added. FIG. 3 is a front view (A), a rear view (B), and a side cross-sectional view (C) of a camera 101 on which a shake correction apparatus according to the present invention is mounted. 3 is a diagram illustrating a specific configuration of a zoom lens unit 70. FIG. It is a figure which shows the structural example of the camera by which the blurring correction apparatus 140 which concerns on this invention is mounted. (A), (B), (D) is a diagram showing an example in which image blurring is determined if the same amount is moved in a specific direction, and (C) is a diagram in which the subject moves like a central portion. FIG. It is a figure which shows the structural example of the camera by which the blurring correction apparatus 150 which concerns on this invention is mounted. It is a figure which shows the structural example of the camera 200 carrying the blurring correction apparatus which concerns on this invention. It is the flowchart 1 regarding the blurring correction process at the time of still image photography. It is the flowchart 2 regarding the blurring correction process at the time of still image photography. It is the flowchart 1 regarding a blurring correction process when panning / tilting operation is performed at the time of video recording. FIG. 9 is a second flowchart relating to a shake correction process when a pan / tilt operation is performed during moving image shooting. It is a figure which shows the example of a characteristic of the crystal | crystallization which produces the primary electro-optic effect. It is a figure which shows the example of a characteristic of the other crystal | crystallization which produces the primary electrooptic effect. It is a figure which shows the example of a characteristic of the crystal | crystallization which produces a secondary electro-optic effect.

Embodiments of the present invention will be described below with reference to the drawings.
<Operating principle>
With reference to FIG. 1, an example of the operation principle and characteristics of a shake correction element made of an electro-optic crystal will be described.

The principle of operation of the vibration reduction element made of KTN crystal (potassium niobate tantalate, KTa _(1-X) Nb _(X) 0 ₃ ) is that by injecting current into an EO crystal that has been conventionally considered an insulator. It is based on the concept of inducing a gradient of refractive index. It is said that a high scanning efficiency of 80 times that of a conventional EO beam scanner is achieved. Compared to current scanner elements such as polygon mirrors and galvanometer mirrors, the shake correction element made of KTN crystal has an element volume of 1/100 and an operation speed of 100 times, improving the performance by two digits. You can expect to.

  A phenomenon in which the refractive index of a material changes when an electric field is applied to such a crystal is referred to as an “electro-optic effect”, and an effect in which the refractive index change is proportional to the applied electric field is referred to as a “first-order electro-optic effect”. (Pockels effect), an effect in which the refractive index change is proportional to the square of the applied electric field is called a “second-order electro-optic effect” (Kerr effect).

  In addition, a crystal having such a characteristic that its refractive index changes when a voltage is applied to the crystal due to the “electro-optic effect” is referred to as an “electro-optic crystal” (EO crystal, Electro-optic crystal). In the case of KTN crystal (potassium tantalate niobate) crystal, “second-order electro-optic effect” (Kerr effect) is exhibited.

  Next, FIG. 1A is a perspective view showing an example of a shake correction element. As shown in FIG. 1A, the blur correction element 11 is made of an electro-optic crystal such as the above-mentioned KTN crystal as a rectangular parallelepiped parallel plate, and a conductive metal or ITO on both opposing surfaces 13a and 13b. A photorefractive element that can be electronically controlled as it is, by calculating a correction amount according to the detected blur amount and variably controlling the voltage applied between the electrodes 15a and 15b according to the correction amount. And can be used as a blur correction element.

  When the above-described gradation distribution of refractive index (space charge control mode EO effect) is used, the electrodes 15a and 15b are not provided on the optical axis (AA ′ line shown in FIG. 1). It is not always necessary to use a transparent electrode as in the case of the deflector according to the above, and neither the transmittance deterioration nor the light amount loss due to the electrodes 15a and 15b occurs.

  Next, FIG. 1B is a schematic diagram showing a state of a refractive index distribution generated when a voltage waveform is applied to the blur correction element 11 shown in FIG. 1A, and FIG. 6 is a graph showing a change in the thickness direction and refractive index of the correction element 11.

  As shown in FIG. 1B, the principle of operation of refractive index change using the KTN crystal is as follows. By applying a predetermined voltage waveform between the electrodes 15a and 15b formed on both opposing surfaces of the electro-optic crystal. When electrons are injected into the electro-optic crystal, the refractive index changes linearly according to the magnitude of the electric field induced between the electrode pairs, and a gradient distribution of the refractive index is generated in the crystal layer ("space" (Referred to as “charge control mode EO effect”), the incident light travels while changing its direction, and the angle of the emitted light changes due to the accumulation of the direction change. If the amount of blur is detected, shooting is performed according to this amount of blur. A new optical blur correction apparatus that tilts the optical axis and cancels image blur on the imaging surface can be realized. This phenomenon is said to be applicable to electro-optic crystals in general, but KTN crystals have a huge dielectric constant of 10000 or more and can be remarkably expressed.

Next, FIG. 1D is a graph showing electric field-refractive index change characteristics of a KTN crystal and lithium niobate (LiNbO ₃ ) as an example of a blur correction element.

  The slope of the graph shown in FIG. 1D corresponds to the electro-optic constant, indicating that the steeper the slope, the greater the change in refractive index, and the same change in refractive index can be caused at a lower voltage. Yes.

The refractive index is indicated by the surface of an ellipsoid (refractive index ellipsoid) in an arbitrary orthogonal coordinate system. Since the length of the principal axis of this ellipsoid often indicates the main refractive index, this refractive index ellipsoid is often used when describing the optical characteristics of the crystal. Here, when the optical parameter (1 / n _ij ² ) is developed by an electric field, the following equation is obtained.
(1 / n _ij ² ) = (1 / n _ij ² ) + γ _ijk · E _k + g _ijkl · E _k · E _l (1)

In the above equation (1), γ _ijk is called a primary electro-optic constant (Pockels constant) and g _ijkl is called a secondary electro-optic constant (Kerr constant).

  For example, the characteristics required of an electro-optic crystal when used in an optical modulator, etc. are low voltage (half-wave voltage) required for 100% modulation, excellent crystal optical uniformity, no optical damage, and insertion loss. There are few, and it has a broadband modulation characteristic.

In general, a ferroelectric crystal has a large primary electro-optic constant (Pockels constant) γ _ijk . In the ferroelectric, the relationship of the following formula (2) is obtained from the treatment of the refractive index change induced by the spontaneous polarization Ps.
γ _ij2 = 2ε ₀ (ε ₁ −1) · g _ij3l · Ps (2)

That is, the γ constant of the ferroelectric phase that is the room temperature phase can be said to be that the secondary electro-optic constant (Kerr constant) g in the paraelectric phase that is the high temperature phase is biased by the spontaneous polarization Ps. A ferroelectric having a high value indicates that the primary electro-optic constant γ is large. Basic values such as the refractive index (n) and the g constant are strongly related to the BO ₆ type oxygen octahedron structure common to many ferroelectric crystals. In particular, the g constant (Kerr constant) is a crystal. It is a substantially constant value regardless of the structure. Therefore, in order to search for a ferroelectric crystal having a large γ constant (Pockels constant) from the above equation (2), one having a large spontaneous polarization Ps and a large dielectric constant ε is one guideline.

  Next, FIG. 2A is a diagram illustrating a second configuration example of the blur correction element. As shown in FIG. 2A, the blur correction element 21 is made of an electro-optic crystal such as a KTN crystal as a rectangular parallelepiped parallel plate as described above, and has a conductor on the surfaces 23a and 23b facing in the Y direction. Electrode 25a and electrode 25b made of metal, ITO, etc. are formed as blur correction element 21Y that refracts in the Y direction. Furthermore, electrodes 29a made of conductor metal, ITO, etc. are provided on surfaces 27a and 27b facing X direction. By using the blur correction element 21X in which the electrode 29b is formed and refracts in the X direction, a similar element in which a counter electrode is provided not only in the X direction but also in the Y direction orthogonal to the X direction is used as the optical axis BB. 'Placed on top of each other.

  Next, FIG. 2B is a diagram illustrating a third configuration example of the blur correction element. As shown in FIG. 2B, the blur correction element 31 is made of a single electro-optic crystal such as a KTN crystal as a rectangular parallelepiped parallel plate, and a conductor metal is formed on the surfaces 33a and 33b facing in the Y direction. And electrodes 35a and 35b such as ITO are formed, and electrodes 35c and 35d such as conductor metal and ITO are formed on the surfaces 33c and 33d facing in the X direction.

Next, FIG. 3A is a diagram illustrating a fourth configuration example of the blur correction element. Since many optical crystals such as KTN crystals having a large electro-optic effect are difficult to produce a large crystal, as shown in FIG. 3A, the KTN crystal has a large electro-optic effect but a large-diameter crystal is difficult to produce. 42a and an optical crystal 42b such as lithium niobate (LiNbO ₃ ) or lithium tantalate (LiTaO ₃ ), which can easily produce a relatively large bulk crystal, are bonded in the vertical direction, and an electrode 45a is attached to the surface 43a of the KTN crystal 42a. The electrode 45b may be formed on the surface 43b of the optical crystal 42b. Note that, instead of lithium niobate (LiNbO ₃ ), optical components such as quartz (SiO ₂ ), quartz glass, and various optical glass materials may be combined or bonded together.

Next, FIG. 3B is a diagram illustrating a fifth configuration example of the shake correction element. Since many optical crystals having a large electro-optic effect, such as a KTN crystal, are difficult to produce a large crystal, as shown in FIG. 3B, KTN has a large electro-optic effect but a large-diameter crystal is difficult to produce. The crystal 52a and an optical crystal 52b such as lithium niobate (LiNbO ₃ ) or lithium tantalate (LiTaO ₃ ) that can easily produce a relatively large bulk crystal are bonded in the direction of the optical axis EE ′. The electrodes 54a and 54b may be formed on the surfaces 53a and 53b, respectively, and the electrodes 56a and 56b may be formed on the surfaces 55a and 55b of the optical crystal 52b, respectively. Note that, instead of lithium niobate (LiNbO ₃ ), optical parts such as quartz (SiO ₂ ), quartz glass, and various optical glass materials may be combined or bonded together.

  Next, FIG. 3C is a diagram illustrating a sixth configuration example of the blur correction element. This is an example in which a prism 62 made of an optical glass material and a blur correction element 31 shown in FIG. 2B made of a KTN crystal are joined to form an integral blur correction element. Used.

  Next, FIG. 4A is a diagram showing a configuration of the zoom lens unit 70 of the optical camera shake correction device, in a state where the prism 62 and the camera shake correction element 31 shown in FIG. Located in the zoom lens unit.

  The zoom lens unit 70 is a bent optical axis type zoom lens unit that is provided in the camera and bends the optical axis I-J incident from the front of the camera at a right angle of 45 degrees by the prism 62. The optical axis I-- A prism 62 that bends incident light incident from the J direction in the direction of the optical axis JK along the hypotenuse, a blur correction element 31 that refracts the light emitted from the prism 62, and light emitted from the blur correction element 31. The image pickup lens group 71 for enlarging the image and the image sensor 73 for picking up an image of the light emitted from the image pickup lens group 71 are configured. Note that FIG. 4A shows a state in which camera shake is not added in addition to the above-described configuration.

  Next, FIG. 4B shows a state where camera shake has been added to the camera. In this figure, no voltage is applied between the electrodes 35a and 35b provided in the blur correction element 31, and the shift correction is not performed. At this time, a blur of an angle θ has occurred with respect to the optical axis I-J of the camera, and the position of the image projected on the image sensor 73 has moved from K to K ′.

  Next, FIG. 4C shows a state where camera shake is corrected in a state where camera shake is added. In this figure, since the voltage V is applied between the electrodes 35a and 35b provided on the shake correction element 31, the optical axis is inclined in the direction opposite to the camera shake direction in the shake correction element 31, so that imaging is performed. The position of the image projected on the element 73 is corrected to K.

As described above, an example of realizing an electronically controlled blur correction device using a transparent dielectric material having electro-optic effect characteristics such as KTN crystal or lithium niobate (LiNbO ₃ ) or an electro-optic crystal has been shown. Is a transparent material (having a high light transmittance in the visible light region) and a material having a large electro-optic effect, especially a second-order electro-optic constant (Kerr constant), other electro-optic crystals and ferroelectrics You may comprise using a body material, a transparent ceramic material, etc.

  Further, a plurality of the above-described blur correction elements may be arranged in a stacked manner so that the refraction angle becomes larger. In addition, a blur correction element with counter electrodes provided on both sides of a rectangular parallelepiped optical crystal is provided at the back of the prism, etc., but the prism itself in a bent optical axis zoom system, etc., is fabricated using an electro-optic crystal. In addition, a blur correction element may be configured by configuring electrodes on the predetermined facing surface.

Electrooptic crystals such as KTN (potassium tantalate niobate) have a higher dielectric constant than conventional electrooptic crystals such as LiNbO ₃ (lithium niobate), and refractive index distribution induced by electron injection (space charge control). Since the refraction angle due to the mode EO effect can be increased, the pan / tilt driving can be performed in a wider angle range than the conventional optical blur correction device such as a variable apex angle prism type or a shift lens type.

  Since only a thin and small shake correction element using an electro-optic crystal needs to be arranged on the optical axis, compared to the conventional optical shake correction apparatus, there is no mechanical drive unit, and the drive mechanism becomes extremely simple, Driving is facilitated by simply applying a current signal such as an AC waveform of a predetermined voltage between the electrode pairs. In addition, since the optical axis can be tilted in a wider angle range than the conventional optical blur correction device, it can also be used for electric panning and tilt driving.

  Further, as shown in FIG. 4, even when the above-described blur correction element is combined with a bent optical axis type zoom, the drive mechanism can be simplified as compared with a conventional rotating mirror type blur correction device and the like. Since only a thin and small blur correction element needs to be arranged behind the prism, a small and thin zoom lens unit with a blur correction mechanism can be configured without significantly changing the optical system.

  Further, chromatic aberration as in the conventional variable apex angle prism system and decentration aberration in the shift lens system do not occur, and it can be used for high quality photography. Further, since it can be used in combination with various photographing lenses, it can also be used for conventional interchangeable lenses and photographing optical systems.

<First Embodiment>
FIG. 5 is a front view (A), a rear view (B), and a side cross-sectional view (C) of the camera 101 on which the shake correction apparatus according to the first embodiment of the present invention is mounted.

  First, as shown in FIG. 5A, a power switch 103, a shutter release 104 for starting / stopping still image shooting, or moving image shooting, a strobe 105, a light receiving window 106, and a grip 107 are provided on the front surface of the camera 101. Furthermore, an Y-direction angular velocity sensor 108 made of, for example, a vibration gyro, for example, an X-direction angular velocity sensor 109 made of a vibration gyro is provided inside the camera 101.

  Next, as shown in FIG. 5B, a shooting mode changeover switch 110, a MENU key 111 for setting shooting conditions and other settings, cursor keys (↑, ↓, ←, →) 112, and a SET key 113. A DISP key 114 for switching display, a zoom switch 115, a shake correction function ON / OFF switch 11, and an image monitor 117 are provided on the back of the camera 101.

  Next, FIG. 5C shows a cross-sectional view when the camera 101 shown in FIG. 5A is cut along the line LL ′. The prism 62, the blur correction element 31, the photographing lens group 71, and the like. It shows that the zoom lens unit 70 provided with the image sensor 73 is built-in.

  Next, FIG. 6 is a diagram showing a specific configuration of the zoom lens unit 70 (see FIG. 4) shown in FIGS.

  As shown in FIG. 6, the zoom lens unit 70 includes a fixed portion 122 that connects and holds the prism 62 and the blur correction element 31 shown in FIGS. 4 and 5 on one surface, and a lens provided on one surface. A unit substrate 121 that fixes a CCD imaging device circuit substrate 123 that captures a light image from the unit 71a to a fixing unit 124 that holds the other surface is provided. A gear 127 that decelerates the rotation of the focus drive motor 125 and transmits it to the pinion 126 and a gear 130 that decelerates the rotation of the zoom drive motor 128 and transmits it to the pinion 129 are rotatable on the fixed portion 124. It is fixed. A guard rail 131 having a longitudinal structure in the Z-axis direction is fixed between the fixed portion 122 and the fixed portion 124, and a pinion 126 and a pinion 129 are rotatably fixed in parallel to the guard rail 131. The focus drive rack 132 has a focus lens portion 71 c and moves in the Z-axis direction on the guard rail 131 according to the rotation of the pinion 126. The zoom drive rack 133 has a zoom lens portion 71b, and moves in the Z-axis direction on the guard rail 131 according to the rotation of the pinion 129. The CCD image pickup device circuit board 123 is provided with a connector 134, and a flexible wiring connected to the connector 134 is connected to a camera control unit (not shown).

  Next, FIG. 7 is a diagram showing a configuration example of a camera equipped with the shake correction apparatus 140 according to the present invention. The shake correction apparatus 140 is equipped with the zoom lens unit 70 shown in FIG. The blur correction device 140 is an example in which a motion vector is detected based on a video signal output from the image sensor 73, an image blur amount is detected by image processing, and the blur correction element 31 is driven.

  The blur correction device 140 sequentially reads out image signals from the image sensor 73 and converts them into digital image data, and image data recording that stores the image data output from the signal processing unit 141 for each frame. A motion vector detecting unit 143 for dividing the image data output from the signal processing unit 141 into a plurality of blocks and obtaining a direction of a motion vector between frames, and a motion vector of each block from the motion vector detecting unit 143 A blur amount calculation unit 144 that determines whether the direction is a fixed direction by the block matching method and determines that the whole is moving in the specific direction by the same amount and outputs a blur amount and a direction, and a blur amount calculation unit The correction amount calculation unit 14 calculates the correction amount in the X direction and the Y direction so that the blur amount disappears based on the blur amount and direction output from the 144. A blur correction unit 146X that generates a voltage signal having a magnitude corresponding to the correction amount in the X direction output from the correction amount calculation unit 145, and a correction amount in the Y direction output from the correction amount calculation unit 145. The blur correction unit 146Y generates a voltage signal having a magnitude, and the blur correction element 31 inputs the voltage signals output from the blur correction unit 146X and the blur correction unit 146Y.

  The blur amount recording unit 147 records the blur amount and direction output from the blur amount calculating unit 144. The display unit 148 displays the blur amount and direction recorded in the blur amount recording unit 147. The camera control unit 149 controls each unit provided in the shake correction device 140.

  Next, the operation of the blur correction apparatus 140 shown in FIG. 7 will be described with reference to an example of image blur for each block shown in FIG.

  Now, it is assumed that the camera equipped with the shake correction device 140 is set to the moving image mode and is operating. At this time, the image sensor 73 outputs an image signal for each frame. The image signal is sequentially read out from the image sensor 73, converted into digital image data by the signal processing unit 141, and output from the signal processing unit 141. Image data is stored in the image data recording unit 142 for each frame.

  Next, the image data output from the signal processing unit 141 is divided into a plurality of blocks by the motion vector detection unit 143, and the direction of the motion vector between frames is obtained. The shake amount calculation unit 144 determines whether the motion vector of each block from the motion vector detection unit 143 is in a certain direction by the block matching method, and the whole is shown in FIGS. 8A, 8B, and 8D. As shown in the figure, if the same amount of movement has been made in a specific direction, it is determined that there is image blur and the blur amount and direction are output.

  On the other hand, in the shake amount calculation unit 144, when the motion vector of each block from the motion vector detection unit 143 is moving as in the central portion shown in FIG. Judgment is not made and the blur amount and direction are not output.

  As described above, when the image blur is determined, the correction amount calculation unit 145 corrects the X direction and the Y direction so that the blur amount disappears based on the blur amount and direction output from the blur amount calculation unit 144. Calculate the amount. Next, the blur correction unit 146X generates a voltage signal having a magnitude corresponding to the correction amount in the X direction output from the correction amount calculation unit 145, and uses this voltage signal as an electrode 35a provided in the blur correction element 31 and the electrode. To 35b. In addition, the blur correction unit 146Y generates a voltage signal having a magnitude corresponding to the correction amount in the Y direction output from the correction amount calculation unit 145, and the voltage signal is applied to the electrode 35c provided in the blur correction element 31 and the electrode. Output to 35d.

  The blur correction element 31 changes the optical axis direction in a direction opposite to the blur direction in accordance with the voltage signal applied between the pair of electrodes in the X and Y directions. Can be suppressed.

  As a result, when a camera shake occurs, the shake can be effectively corrected, and the drive mechanism of the shake correction apparatus can be simply configured, and a device such as a camera with the shake correction apparatus can be realized in a small size and a thin shape. .

  As described above, the shake correction device is configured by the shake correction element using an electro-optic crystal such as a KTN crystal in which the refractive index changes depending on the applied electric field or the gradation distribution of the refractive index is generated in the layer. In addition to being able to realize a shake correction device with an extremely simple configuration that does not have a drive part or wear part, the drive control is facilitated, and the reliability and durability of the shake correction apparatus can be improved. In combination with the zoom lens unit, etc., it is possible to realize a thin and small camera with an optical blur correction function.

<Second Embodiment>
Next, FIG. 9 is a diagram showing a configuration example of a camera equipped with a shake correction apparatus 150 according to the second embodiment of the present invention. The shake correction device 150 calculates a shake correction amount based on the camera shake amount detected by an angular velocity sensor such as a vibration gyro, and adds a voltage waveform to the counter electrode of the electro-optic crystal according to the calculated correction amount. In this example, the imaging optical axis is bent to suppress image blur on the imaging surface.

As the angular velocity sensors 108 and 109 shown in FIG. 9, a sound piece type vibration gyro, vibration gyro, and piezoelectric vibration gyro are preferable. The triangular prism-shaped sound piece type vibration gyro has the advantage that the resonance frequency can be adjusted without affecting the vibration posture and other sides by trimming the ridge line in the vibration direction while taking advantage of the high sensitivity of the resonance type. Further, there are a piezoelectric vibration gyro using a ceramic bimorph vibrator and a piezoelectric vibration gyro using a piezoelectric ceramic. When shooting while standing on a non-moving ground, there are generally many camera shakes of about 3 to 10 Hz, but when shooting while walking, when shooting on a train or vehicle, about 10 to 18 Hz. Since a blur of about 20 to 25 Hz also occurs, the response is 50 Hz and the detection range is ± 360 deg. So as to cope with the occurrence of a blur of about 0.5 to 25 Hz. An ultra-small sensor of about / sec can be used.

  In addition, in order to remove the temperature drift of the stationary output due to the change of the ambient temperature, an HPF (with a cutoff frequency fc = about 0.3 to 0.5 Hz) is connected to the sensor output to remove the DC component, In order to remove vibration noise (such as around 20 to 25 kHz) inside the sensor, an LPF (low pass filter) that removes high frequency components higher than the response frequency (cutoff frequency fc = 1 kHz to about 4 kHz) may be connected.

  The integrators 151 and 155 remove the high-frequency signal from the signals detected by the angular velocity sensors 108 and 109, pass the low-frequency signal (about 0.5 to 25 Hz), integrate and convert it into angular displacement, and convert the angular velocity signal. Alternatively, a blur amount signal is output. The correction amount calculation units 152 and 156 calculate the shake correction amount according to the angular velocity or the shake amount output from the integrators 151 and 155.

  The driver (X) 153 and the driver (Y) 157 generate voltage waveforms to be applied between the electrode pairs on the opposing surfaces of the shake correction elements 21X and 21Y according to the correction amounts calculated by the correction amount calculation units 152 and 156.

  Next, the operation of the shake correction apparatus 150 shown in FIG. 9 will be described.

  Now, it is assumed that the camera equipped with the shake correction device 150 is set to the moving image mode and is operating. At this time, the signal detected by the angular velocity sensor 109 is input to the integrator 151, the high-frequency signal is removed, integrated, converted into an angular displacement, and an angular velocity signal or a shake amount signal is output. The correction amount calculation unit 152 calculates and outputs a shake correction amount according to the angular velocity or the shake amount output from the integrator 151. Further, the driver (X) 153 generates a voltage signal to be applied between the electrode pairs on the opposing surfaces of the shake correction element 21X according to the correction amount calculated by the correction amount calculation unit 152.

  The voltage signal from the driver (X) 153 is output to the electrodes 29a and 29b provided in the shake correction element 21X. The blur correction element 21X changes the optical axis direction in a direction opposite to the blur direction in accordance with a voltage signal applied between the pair of electrodes in the X direction, thereby suppressing image blur on the imaging surface due to blur. it can.

  Similarly, the signal detected by the angular velocity sensor 108 is converted into an angular displacement by the integrator 155, and an angular velocity signal or a shake amount signal is output. A blur correction amount is calculated by the correction amount calculator 156 according to the angular velocity or the blur amount output from the integrator 155. Further, the driver (Y) 157 generates a voltage signal to be applied between the electrode pairs on the opposing surfaces of the shake correction element 21Y according to the correction amount calculated by the correction amount calculation unit 156. The voltage signal from the driver (Y) 157 is output to the electrodes 25a and 25b provided in the shake correction element 21Y. The blur correction element 21Y changes the optical axis direction in a direction opposite to the blur direction in accordance with a voltage signal applied between the electrode pair in the Y direction, so that image blur on the imaging surface due to blur can be suppressed. it can.

  As a result, when a camera shake occurs, the shake can be effectively corrected, and the drive mechanism of the shake correction apparatus can be simply configured, and a device such as a camera with the shake correction apparatus can be realized in a small size and a thin shape. .

  In the above blur correction device, if the correction amount is set so as to simply cancel out the change in angle, a delay will occur. Therefore, the angular acceleration is calculated by taking the difference between the angular velocity at the time of detection and the angular velocity at the time of previous detection. Then, control may be performed such that the degree of acceleration / deceleration is determined using history information such as angular acceleration for two cycles or more, and the angular velocity at the next detection is predicted and calculated.

  In addition, when the shake correction angle approaches the limit of the correctable range, the voltage applied to the shake correction element is gradually switched to a low voltage, and the centering process and return process for gradually returning to the correctable range or midpoint position. You may control to perform.

  As described above, even if an electro-optic crystal has a large electro-optic effect and a scan efficiency of 12 degrees and a large electro-optic crystal such as KTN (potassium niobate tantalate) is used, driving voltage and power consumption are small. The camera shake correction angle (usually about ± 2.5 degrees) is sufficient, and can be used for camera shake correction devices of cameras.

  Further, not only the X direction blur correction element using an electro-optic crystal but also a blur correction element that refracts in the Y direction perpendicular to the X direction can be arranged adjacent to the optical axis to detect X, Y detected by a vibration gyroscope or the like. Depending on the amount of blurring in the direction, a correction driving current waveform is added between the pair of opposing electrodes in both the X and Y directions, so that blurring correction in both the X and Y directions can be performed. Can be realized.

  In addition, if a rectangular parallelepiped blur correction element using one electro-optic crystal is provided with an electrode pair on the opposite surface in the Y direction in addition to the X direction, blur correction in both the X and Y directions can be performed.

  In any case, compared with the conventional optical correction device, there is no mechanical drive unit or wear parts, the drive mechanism becomes extremely simple, and the drive becomes easy only by adding a current signal such as an AC waveform of a predetermined voltage.

  For example, a thin camera using a bent optical axis type zoom lens using a prism can be provided with an optical blur correction device simply by providing a blur correction element using such a small electro-optic crystal behind the prism. Easy to configure.

<Third Embodiment>
Next, FIG. 10 is a diagram showing a configuration example of a camera 200 equipped with a shake correction apparatus according to the third embodiment of the present invention.

  As shown in FIG. 10, the camera 200 includes a control circuit 240 including a zoom lens unit 210 and a camera control unit 241. The camera control unit 241 generates a blur signal for generating a voltage signal to be applied between the electrode pairs on the opposite surfaces of the blur correction element 21X shown in FIG. 2A according to the blur correction amount calculated by the blur correction amount calculation unit 245. A blur correction element Y-direction drive unit 216 that generates a voltage signal to be applied between the pair of electrodes on the opposite surface of the blur correction element 21Y according to the blur correction amount calculated by the correction element X-direction drive unit 215 and the blur correction amount calculation unit 245, A focus lens driving unit 217 for performing AF processing, a zoom lens driving unit 218 for driving the zoom lens unit 210, an aperture driving unit 219 for driving the diaphragm 211, a shutter driving unit 220 for driving the shutter 212, and FIG. A video signal processing unit 221 that converts an image signal output from the image sensor 73 shown in FIG. The timing control unit 222 which drives giving a timing signal to an imaging on the imaging element 73 in response to the start signal from the La controller 241 is connected.

  Further, the camera control unit 241 has a shake amount (θx) obtained by removing the high-frequency signal from the signal from the angular velocity detection unit 223 to which the angular velocity sensor 109 shown in FIG. An integrator 224 that outputs a signal to the camera control unit 241 and an angular velocity detection unit 223 to which an angular velocity sensor (Y) 109 is connected are connected. The camera control unit 241 is connected to an angular velocity detection unit 225 to which an integrator 226 and an angular velocity sensor (X) 108 are connected. Further, a distance measuring sensor 228 that performs white balance processing and distance measurement processing is connected to the camera control unit 241, and a distance measurement processing unit 229 that performs white balance processing and distance measurement processing, and a strobe driving unit 230 that drives the strobe 105. It is connected.

  The camera control unit 241 is connected to an operation unit 253 that outputs signals from various keys shown in FIG. The camera control unit 241 further includes an image processing unit 250 that converts the format of the image data input from the video signal processing unit 221 into a predetermined data format, compresses and encodes the image data, and decompresses the encoded data. A compression encoding / decompression decoding unit 251 for decoding back to image data and a still image / moving image memory 252 for storing still image or moving image data or compression encoded data are connected.

  In addition, the camera control unit 241 reads the captured image data and the display memory 247 for storing the image data read from the still image / moving image memory 252 and the display memory 247 at a predetermined rate. A display driving unit 248 that drives to display on the image monitor 117 is connected.

  Further, the camera control unit 241 includes a digital image processing unit 242 that performs image processing on image data after being captured, an image buffer memory 243 that adjusts a delay time to display the image data through, an integrator 224, and the like. Based on the shake amount calculation unit 244 for detecting the shake amount (θx, θy) sequentially from the shake amount signal (θx, θy) from 226, and the shake amount (θx, θy) detected by the shake amount calculation unit 244. A blur correction amount calculation unit 245 that calculates a blur correction amount in the X / Y direction and a pann / tilt operation amount calculation unit 246 that calculates a pan operation amount or a tilt operation amount according to the blur correction amount in the X / Y direction are connected. Has been.

  Next, the operation of the camera 200 shown in FIG. 10 will be described with reference to the flowcharts shown in FIGS. 11A and 11B. FIG. 11A and FIG. 11B are flowcharts relating to blur correction processing during still image shooting.

  Now, in order to use the camera 200 in the still image mode, it is assumed that the MENU key 111 shown in FIG. 5 has been input to the camera control unit 241 from the operation unit 253.

  First, in step S <b> 10, the camera control unit 241 determines whether the shutter switch (release) 104 is in a half-pressed state via the operation unit 253.

  If the shutter switch (release) 104 shown in FIG. 5 is half-pressed, the process advances to step S20, and the camera control unit 241 performs measurement by the distance measurement processing unit 229 so as to perform photometry processing and distance measurement processing. The distance sensor 228 is controlled, the focus lens driving unit 217 is controlled to perform the AE / AF lock process, and the exposure time T1 is set according to the photometric value and the set exposure condition.

  Next, in step S30, the camera control unit 241 determines whether or not the operation unit 253 has input that the shake correction function ON / OFF switch 116 illustrated in FIG. 5 is turned on in order to validate the shake correction function. Judging.

  A signal from the angular velocity detector 223 to which the angular velocity sensor 109 is connected is input to the integrator 224, the high-frequency signal is removed, the integration calculation is performed, and the shake amount (θx) signal converted into the angular displacement is input to the camera controller 241. ing. At the same time, a signal is input to the integrator 226 from the angular velocity detection unit 225 to which the angular velocity sensor 108 is connected, a high frequency signal is removed, an integration operation is performed, and a shake amount (θy) signal converted into an angular displacement is sent to the camera control unit 241. Have been entered.

  Here, in step S50, the camera control unit 241 outputs the shake amount signals (θx, θy) from the integrator 224 and the integrator 226 to the camera shake amount calculation unit 244, and sequentially outputs them to the camera shake amount calculation unit 244. The blur amount (θx, θy) is detected.

  Next, in step S60, the camera control unit 241 displays the image stabilization ON on the image monitor 117 used as a viewfinder when the camera shake amount calculation unit 244 sequentially detects the image blur amount (θx, θy). It is determined whether or not the shake correction process is ready. If it is not ready for shake correction processing, the process proceeds to step S90.

  When the camera shake correction process is ready, the process proceeds to step S70, and the camera control unit 241 performs the camera shake correction amount calculation unit 245 based on the camera shake amount calculation unit 244 (θx, θy). To calculate the blur correction amount in the X / Y direction.

  Next, in step S80, the camera control unit 241 outputs the blur correction amount in the X direction calculated by the blur correction amount calculation unit 245 to the blur correction element X direction driving unit 215, and calculates the calculated blur correction amount in the Y direction. Is output to the blur correction element Y-direction drive unit 216.

  Here, in the shake correction element X direction drive unit 215, a voltage signal to be applied between the pair of electrodes on the opposite surface of the shake correction element 21X is generated according to the shake correction amount calculated by the shake correction amount calculation unit 245. This voltage signal is output to the electrodes 29a and 29b provided in the shake correction element 21X. The blur correction element 21X changes the optical axis direction in a direction opposite to the blur direction in accordance with a voltage signal applied between the pair of electrodes in the X direction, thereby suppressing image blur on the imaging surface due to blur. it can.

  Similarly, in the shake correction element Y-direction drive unit 216, a voltage signal to be applied between the pair of electrodes on the opposite surface of the shake correction element 21Y is generated according to the shake correction amount calculated by the shake correction amount calculation unit 245. This voltage signal is output to the electrodes 25a and 25b provided in the shake correction element 21Y. The blur correction element 21Y changes the optical axis direction in a direction opposite to the blur direction in accordance with a voltage signal applied between the electrode pair in the Y direction, so that image blur on the imaging surface due to blur can be suppressed. it can.

  At this time, the camera control unit 241 gives a start signal to the timing control unit 222 to start imaging. In response to this, the image signal output from the image sensor 73 is input to the video signal processing unit 221 and converted into digital image data. Further, the digital image processing unit 242 performs image processing, and then the display memory performs image processing. Output data. Further, by driving the display driving unit 248 so as to read out from the display memory 247 at a predetermined rate and display it on the image monitor 117, an image of the subject is displayed from the image monitor 117. As a result, an image in which blurring is suppressed can be displayed.

  Next, in step S <b> 90, the camera control unit 241 determines whether or not the shutter switch (release) 104 is in a fully pressed state via the operation unit 253.

  If the shutter switch (release) 104 is fully pressed, the process advances to step S100, and the camera control unit 241 causes the exposure time timer to start timing.

  Next, in step S110, the camera control unit 241 determines whether or not the shake correction function ON / OFF switch 116 is turned on. If the shake correction function ON / OFF switch 116 is not turned on, the process proceeds to step S150.

  Now, shake amount (θx, θy) signals are input from the integrator 224 and the integrator 226 to the camera control unit 241. If the blur correction function ON / OFF switch 116 is turned on, the process proceeds to step S120, and the camera control unit 241 receives the blur amount signals (θx, θy) from the integrator 224 and the integrator 226. The camera shake amount calculation unit 244 outputs it to the camera shake amount calculation unit 244 to detect the shake amount (θx, θy) sequentially, and the detected shake amount (θx, θy) is sequentially stored in a memory (not shown). Record.

  Next, in steps S130 and S140, the processes in steps S70 and S80 described above are performed. As a result, the blur correction element 21X changes the optical axis direction in a direction opposite to the blur direction according to the voltage signal applied between the pair of electrodes in the X direction. Can be suppressed. At the same time, the blur correction element 21Y changes the optical axis direction in a direction opposite to the blur direction in accordance with a voltage signal applied between the electrode pair in the Y direction, thereby suppressing image blur on the imaging surface due to blur. be able to.

  Next, in step S150, the camera control unit 241 reads the time T from the exposure time timer, and determines whether the time T has reached the exposure time T1. If the time T has not reached the exposure time T1, the process returns to step S110 and the above-described processing is repeated.

  When the time T has reached the exposure time T1, the process proceeds to step S160, and the camera control unit 241 gives a start signal to the timing control unit 222 to start imaging. In response to this, an image signal output from the image sensor 73 is input to the video signal processing unit 221 and converted into digital image data. Further, the digital image processing unit 242 performs image processing, and then compression encoding / Control is performed so that the decompression decoding unit 251 compresses and encodes the image data and records the compression-encoded still image data in the still image / moving image memory 252.

<Fourth Embodiment>
Next, a fourth embodiment of the present invention will be described by applying to the configuration example of the camera 200 shown in FIG. The operation of the camera 200 will be described with reference to the flowcharts shown in FIGS. 12A and 12B. FIGS. 12A and 12B are flowcharts related to blur correction processing when a pan / tilt operation is performed during moving image shooting.

  Now, in order to use the camera 200 in the moving image shooting mode, it is assumed that the MENU key 111 shown in FIG. 5 has been input to the camera control unit 241 from the operation unit 253.

  First, in step S210, the camera control unit 241 determines whether the MENU key 111 is set to the moving image shooting mode via the operation unit 253 illustrated in FIG.

  If the MENU key 111 is set to the moving image shooting mode, the process advances to step S220, and the camera control unit 241 sets the distance measurement processing unit 229 to perform photometry processing, distance measurement processing, and WB (white balance) processing. Control.

  Next, in step S230, the camera control unit 241 determines whether or not the operation unit 253 has input that the shake correction function ON / OFF switch 116 is turned on in order to determine whether or not the shake correction function is valid. to decide.

  In FIG. 10, when a signal is input to the integrator 224 from the angular velocity detection unit 223 to which the angular velocity sensor 109 is connected, the amount of blurring (θx) obtained by removing the high-frequency signal and performing integration and converting into an angular displacement. A signal is input to the camera control unit 241. At the same time, when a signal is input to the integrator 226 from the angular velocity detection unit 225 to which the angular velocity sensor 108 is connected, the blur amount (θy) signal obtained by removing the high-frequency signal and integrating and converting it into an angular displacement is controlled by the camera. Is input to the unit 241.

Here, in step S250, the camera control unit 241 outputs the shake amount signals (θx, θy) from the integrator 224 and the integrator 226 to the shake amount calculation unit 244, and sequentially outputs the shake amount calculation unit 244 to the shake amount calculation unit 244. The blur amount (θx, θy) is detected.
Next, in step S260, the camera control unit 241 determines whether or not there is a panning (X direction) operation by pressing the cursor key (← or →) from the operation unit 253. If there is no panning (X direction) operation, the process proceeds to step S280. On the other hand, if there is a panning (X direction) operation in step S260, the process proceeds to step S270.

  If it is determined in step S260 that there is a panning (X direction) operation, the process proceeds to step S270, and the camera control unit 241 uses the panning operation amount calculated by the panning / tilting operation amount calculation unit 246 to determine the shake correction element X. It outputs to the direction drive part 215.

Here, the shake correction element X-direction drive unit 215 generates a voltage signal to be applied between the pair of electrodes on the opposite surface of the shake correction element 21X according to the pan operation amount calculated by the pan / tilt operation amount calculation unit 246. Therefore, this voltage signal is output to the electrodes 29a and 29b provided in the shake correction element 21X. The blur correction element 21X changes its refractive index according to the voltage signal applied between the pair of electrodes in the X direction and tilts the optical axis direction in the X direction. be able to.
On the other hand, when it is determined in step S260 that there is no panning (X direction) operation, in step S280, the camera control unit 241 tilts (Y or Y) by pressing the cursor key (↑ or ↓) from the operation unit 253. Determine whether there is a (direction) operation. If there is no tilt (Y direction) operation, the process proceeds to step S300. If there is a tilt (Y direction) operation in step S280, the process proceeds to step S290.

  If it is determined in step S280 that there is a tilt (Y direction) operation, the process proceeds to step S290, where the camera control unit 241 uses the tilt operation amount calculated by the pann / tilt operation amount calculation unit 246 as the shake correction element Y. It outputs to the direction drive part 216.

  Here, the shake correction element Y-direction drive unit 216 generates a voltage signal to be applied between the pair of electrodes on the opposite surface of the shake correction element 21Y according to the tilt operation amount calculated by the pan / tilt operation amount calculation unit 246. Therefore, this voltage signal is output to the electrodes 25a and 25b provided in the shake correction element 21Y. The blur correction element 21Y changes its refractive index according to the voltage signal applied between the pair of electrodes in the Y direction and tilts the optical axis direction in the Y direction, so that the imaging surface is tilted relative to the imaging element 73. be able to.

  Next, when the zoom switch 115 is in a pressed state, the process proceeds to step S300, and the camera control unit 241 controls the lens unit 71a and the zoom lens unit 71b by the zoom lens driving unit 218 so as to perform zoom processing, and AF The focus lens driving unit 217 is controlled to perform processing.

  Next, in step S310, the camera control unit 241 determines whether or not the shake correction function ON / OFF switch 116 is turned on. If the shake correction function ON / OFF switch 116 is not turned on, the process proceeds to step S400. On the other hand, if the blur correction function ON / OFF switch 116 is ON, the process proceeds to step S320.

  Next, when it is determined in step S310 that the shake correction function ON / OFF switch 116 is turned on, in step S320, the camera control unit 241 determines whether or not a panning (X direction) operation is being performed. . If a panning (X direction) operation is being performed, the process proceeds to step S330. On the other hand, if the panning (X direction) operation is not being performed, the process proceeds to step S350.

  Next, in step S330, the camera control unit 241 outputs the shake amount signal (θy) from the integrator 224 to the shake amount calculation unit 244, and the shake amount calculation unit 244 sequentially detects the shake amount (θy). Further, based on the detected blur amount (θy), the blur correction amount calculation unit 245 calculates the blur correction amount in the Y direction.

  Next, in step S <b> 340, the camera control unit 241 outputs the shake correction amount in the Y direction calculated by the shake correction amount calculation unit 245 to the shake correction element Y direction driving unit 216.

  As a result, the blur correction element 21Y refracts the optical axis direction in the direction opposite to the blur direction in accordance with the voltage signal applied between the electrode pair in the Y direction. Can be suppressed.

  If it is determined in step S320 that the panning (X direction) operation is not being performed, the process proceeds to step S350, and the camera control unit 241 determines whether the tilt (Y direction) operation is being performed. If the tilt (Y direction) operation is being performed, the process proceeds to step S360. On the other hand, if the tilt (Y direction) operation is not being performed, the process proceeds to step S380.

  Next, in step S360, the camera control unit 241 outputs the shake amount signal (θx) from the integrator 226 to the shake amount calculation unit 244, and the shake amount calculation unit 244 sequentially detects the shake amount (θx). Further, based on the detected blur amount (θx), the blur correction amount calculation unit 245 calculates the blur correction amount in the X direction.

  Next, in step S <b> 370, the camera control unit 241 outputs the shake correction amount in the X direction calculated by the shake correction amount calculation unit 245 to the shake correction element X direction driving unit 215.

  As a result, the blur correction element 21X changes the optical axis direction in a direction opposite to the blur direction according to the voltage signal applied between the pair of electrodes in the X direction. Can be suppressed.

  If it is determined in step S350 that the tilt (Y direction) operation is not being performed, that is, if the panning (X direction) operation or the tilt (Y direction) operation is not being performed, normal blur correction processing is performed. The process proceeds to step S380.

  In step S380, the camera control unit 241 causes the shake correction amount calculation unit 245 to calculate the shake correction amount in the X / Y direction based on the shake amount (θx, θy) detected by the camera shake amount calculation unit 244.

  Next, in step S390, the camera control unit 241 outputs the shake correction amount in the X direction calculated by the shake correction amount calculation unit 245 to the shake correction element X direction driving unit 215, and the calculated shake correction amount in the Y direction. Is output to the blur correction element Y-direction drive unit 216.

  Here, in the shake correction element X direction drive unit 215, a voltage signal to be applied between the pair of electrodes on the opposite surface of the shake correction element 21X is generated according to the shake correction amount calculated by the shake correction amount calculation unit 245. This voltage signal is output to the electrodes 29a and 29b provided in the shake correction element 21X. The blur correction element 21X changes the optical axis direction in a direction opposite to the blur direction in accordance with a voltage signal applied between the pair of electrodes in the X direction, thereby suppressing image blur on the imaging surface due to blur. it can.

  Similarly, in the shake correction element Y-direction drive unit 216, a voltage signal to be applied between the pair of electrodes on the opposite surface of the shake correction element 21Y is generated according to the shake correction amount calculated by the shake correction amount calculation unit 245. This voltage signal is output to the electrodes 25a and 25b provided in the shake correction element 21Y. The blur correction element 21Y changes the optical axis direction in a direction opposite to the blur direction in accordance with a voltage signal applied between the electrode pair in the Y direction, so that image blur on the imaging surface due to blur can be suppressed. it can.

  Next, in step S400, the camera control unit 241 gives a start signal to the timing control unit 222 to start imaging. In response to this, the image signal output from the image sensor 73 is input to the video signal processing unit 221 and converted into digital image data. Further, the digital image processing unit 242 performs image processing, and then the display memory performs image processing. Output data. Further, by driving the display drive unit 248 so that the image is read from the display memory 247 at a predetermined rate and displayed on the image monitor 117, the image of the subject is displayed through the image monitor 117. As a result, an image in which blurring is suppressed can be displayed.

  In the detection of the shake amount, for example, a two-axis piezoelectric vibration gyro that detects a lateral rotation (yaw rotation) around the Y axis and a vertical rotation (pitch rotation) around the X axis is used. An axial angular velocity sensor is used. Further, the angular displacement can be obtained by integrating the detected angular velocity. Furthermore, an acceleration sensor that detects acceleration such as translation in the X-axis direction and translation in the Y-axis direction is provided so that not only the rotational angular velocity but also acceleration and vibration in the direction parallel to each axis can be detected. May be.

  In the present embodiment, according to the blur correction process flowchart during moving image (movie) shooting, during through display or during moving image shooting, through display and shooting recording operation are performed while performing a pan / tilt operation according to a user operation. However, the present invention is not limited to such a case. That is, during panning (lateral movement) operation, horizontal (yaw) rotation direction blur correction is not performed, but only vertical (pitch) rotation direction blur correction is performed, and conversely, during tilt (vertical movement) operation, vertical (pitch) It is also possible to control the through display and shooting / recording operation while performing only the horizontal direction (yaw rotation) blur correction without performing the blur correction in the rotation direction.

  In addition, according to the present embodiment, the panning / tilting operation is performed according to the user's switch operation, so that the shooting direction can be moved by the switch operation without moving the direction of the camera itself. The occurrence of camera shake can be suppressed.

  Also, since beginners can easily perform panning and tilting at a constant speed slowly, camera shake due to the pan / tilt operation is less likely to occur, and the photographer can concentrate on the camera holding posture. In addition, in the past, it is possible that the viewer who was watching the screen displayed during playback would get drunk, but according to this embodiment, the screen displayed during playback does not shake. It is possible to provide an easy-to-see moving image without causing a person to get drunk.

  Since a shake correction element made of a KTN crystal with a large change in refraction angle is used, unlike conventional optical correction devices, pan / tilt drive is performed not only for shake correction but also in a wide angle range sufficient for movie shooting. be able to.

  In addition, a pan / tilt operation switch such as a cursor switch is pressed according to the user's operation, and it is possible to reliably determine whether the camera shake or the pan / tilt operation is performed simply by determining whether or not the electric pan / tilt operation is in progress. Therefore, a complicated discrimination process between the camera shake process and the pan / tilt operation process as in the prior art becomes unnecessary.

  In addition, according to the present embodiment, in video shooting, when performing vertical (pitch) blur correction during horizontal panning operation, horizontal (yaw) blur correction is not performed, and conversely, in the vertical direction When performing horizontal (yaw) shake correction during tilt operation, control is performed so that vertical (pitch) shake correction is not performed. When panning or tilting is not being performed, horizontal (yaw) and Since control is performed so that vertical (pitch) shake correction is performed, troublesome processing such as limiting shake correction or correcting the centering speed when it is determined to be pan / tilt can be eliminated. Also, there is no swing back after the pan / tilt operation. In addition, since misidentification does not occur, followability is good, and blur correction in a rotation direction orthogonal to the operation rotation direction can be sufficiently performed even during the pan / tilt operation.

  Also, during the pan / tilt operation according to the user operation, control is performed so as to switch the driving speed for changing the refraction angle of the blur correction element according to the focal length of the zoom optical system or the shooting angle of view (viewing angle). The driving speed may be slower as the distance becomes longer or the angle of view range becomes narrower. Accordingly, the moving speed (angular speed) is substantially constant with respect to the range in the frame of the finder screen, and it is possible to take a picture with a natural operation feeling.

  Similarly, in moving image shooting, the optical field of view of the optical system is intentionally tilted by a shake correction element in response to an electronic pan / tilt operation input using an operation switch. In addition, an electric pan / tilt operation can be performed, and the occurrence of camera shake in moving image shooting can be suppressed.

  For example, when shooting a still image, if the pan / tilt operation is performed by a user operation, after performing the pan / tilt operation or zoom operation, the angular velocity around the horizontal / vertical axis detected at the time of shooting with the release key is set. In response, shoot with image stabilization. Also, during live view and movie shooting, live view and shooting / recording operations are performed while performing pan / tilt operations by user operation. During panning (lateral movement), the horizontal (yaw) rotation direction around the vertical axis is performed. Without blur correction, only blur correction in the vertical (pitch) rotation direction around the horizontal axis is performed. Conversely, during tilt (vertical movement) operation, blur correction in the vertical (pitch) rotation direction around the horizontal axis is performed. Instead, it is only necessary to control the through display and shooting / recording operation while performing only the blur correction in the horizontal direction (yaw rotation) around the vertical axis.

  Pan / tilt can be determined reliably based on whether the operation switch used for pan / tilt operation has been pressed or whether the pan / tilt operation is in progress. become. In addition, because the pan / tilt drive is driven according to the switch operation without moving the camera direction, camera shake is less likely to occur during the pan / tilt operation, and shake correction in the pan operation direction (yaw rotation) is performed during the pan operation. Without tilting, no shake correction is performed in the tilt operation direction (pitch rotation) during tilt operation, so there is no swing back phenomenon, no need for shake back correction processing, and other directions during panning and tilting operations. The image stabilization can be sufficiently performed.

  13 is a diagram showing an example of the characteristics of a crystal that produces a primary electro-optic effect, FIG. 14 shows an example of the characteristics of another crystal that produces a primary electro-optic effect, and FIG. It is a figure which shows the example of a characteristic of the crystal | crystallization which produces an optical effect. The characteristic examples shown in FIGS. 13 to 15 are based on the “Optical Technology Handbook Supplement” published in 1976 by Asakura Shoten.

  Among such various dielectrics and optical crystals, the first-order electro-optic coefficient (Pockels constant γ), in particular, the second-order electro-optic coefficient (Kerr constant g) is large in the blur correction element of this embodiment. Available.

  In addition, sintered materials such as PZT (lead zirconate titanate) and PLZT (lead zirconate titanate doped with lanthanum) and ceramics, which are also used in piezoelectric materials, transmit visible light and transmit transmittance. If a transparent ceramic thin film having a high thickness can be formed, or if the change in refractive index is large and the electro-optic effect is large, the same can be used to form a shake correction element.

In general, a sintered body made of crystal fine particles or a ceramic of metal oxide does not have transparency even if a single crystal is transparent even if pores are present. If this is made into fine particles of uniform phase and the internal pores are eliminated, a permeable ceramic can be obtained. As the sintering, there are a method (hot press method) of sintering after expelling the internal gas by high-temperature treatment in a reduced pressure state, or sintering while pressurizing to several hundred kg / cm ² .

  Alternatively, by using a rainbow method (aerosol deposition method) in which PLZT powder raw material is sprayed at high speed under a low vacuum, a transparent and dense ceramic film thin film of PLZT made of microcrystals may be used. good.

For example, it is manufactured by adding a small amount of lanthanum (La ³⁺ ) or viscous (Bi ³⁺ ) to PZT (lead zirconate titanate) and hot pressing at 200 to 600 kg / cm ² at 1000 to 1300 ° C. for several hours. There are examples of electro-optic materials made of transparent ceramics.

  DESCRIPTION OF SYMBOLS 21 ... Blur correction element, 21X ... Blur correction element, 21Y ... Blur correction element, 62 ... Prism, 70 ... Zoom lens unit, 71 ... Shooting lens group, 73 ... Imaging element, 108 ... Angular velocity sensor, 109 ... Angular velocity sensor, DESCRIPTION OF SYMBOLS 140 ... Shake correction apparatus 141 ... Signal processing part 142 ... Image data recording part 143 ... Vector detection part 144 ... Blur amount calculation part 145 ... Correction amount calculation part 146 ... Blur correction drive part, 146X ... Blur correction 146Y ... blur correction unit, 147 ... blur amount recording unit, 148 ... display unit, 149 ... camera control unit, 150 ... blur correction device, 151 ... integrator, 152 ... correction amount calculation unit, 155 ... integrator, 156 ... Correction amount calculation unit 210... Zoom lens unit 216. Direction drive unit 217. Focus lens drive unit 218. Zoom lens drive unit 21 ... Driver, 221 ... Video signal processor, 222 ... Timing controller, 223 ... Angular velocity detector, 224 ... Integrator, 225 ... Angular velocity detector, 226 ... Integrator, 228 ... Distance sensor, 229 ... Distance process 230, strobe drive unit, 240 ... control circuit, 241 ... camera control unit, 242 ... digital image processing unit, 243 ... image buffer memory, 244 ... camera shake amount calculation unit, 245 ... blur correction amount calculation unit, 246 ... Pan / tilt operation amount calculation unit, 247 ... display memory, 248 ... display drive unit, 250 ... image processing unit, 251 ... decompression decoding unit, 252 ... video image memory, 253 ... operation unit

Claims (5)

An optical material that generates a gradient of refractive index in the layer according to the applied voltage;
A photographing optical system in which the optical material is disposed on a photographing optical axis;
Imaging means for imaging a subject image formed on the imaging surface by the imaging optical system;
Detecting means for detecting a panning amount or a tilting amount corresponding to a panning operation or a tilting operation;
Driving means for applying a voltage to the optical material;
The following panning amount or tilt amount detected by the detecting means, an imaging apparatus Ru and control means for controlling said drive means to move the object image formed on the imaging surface of the imaging means,
The optical material is
A first electrode is formed on an opposing surface in a first direction orthogonal to the direction of the photographic optical axis, and a first blur that tilts the photographic optical axis according to a voltage applied to the first electrode. A correction element;
According to the voltage applied to the second electrode, a second electrode is formed on the opposing surface of the second direction perpendicular to the direction of the photographing optical axis and perpendicular to the first direction. An image pickup apparatus comprising a shake correction element including a second shake correction element that tilts the photographing optical axis . A blur detection means for detecting the blur amount of the generated blur;
Correction amount calculating means for calculating a shake correction amount according to the shake amount detected by the shake detection means, further comprising:
The control means blurs an image on the imaging surface of the imaging means in a direction orthogonal to the moving direction of the subject image according to the panning operation or the tilting operation according to the correction amount calculated by the correction amount calculation means. The imaging apparatus according to claim 1, wherein the driving unit is further controlled so as to be suppressed. The photographing optical system is
A reflector that bends incident light from the subject 45 degrees and guides it to the photographing optical system;
It consists of a zoom lens optical system with variable focal position,
The optical material is
The imaging apparatus according to claim 1, wherein the imaging apparatus is arranged on the image side rear side of the reflector on the imaging optical axis of the imaging optical system and on the subject side front side of the zoom lens optical system. The optical material is
The imaging device according to claim 1, wherein the imaging device is one of KTN crystal, lithium niobate, lithium tantalate, and barium titanate, or an oxide dielectric crystal. The optical material is
The imaging apparatus according to claim 1, wherein the imaging apparatus is any one of ceramics made of PLZT having electro-optical characteristics, transparent ceramics, and a sintered body of a ferroelectric material.

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