JP4645523B2 - Optical device, shake correction device, camera system, interchangeable lens, mobile phone - Google Patents

Description

  The present invention relates to an optical device, a shake correction device using the optical device, a camera system including the shake correction device, an interchangeable lens using the optical device, a mobile phone with a camera function, a control method for the shake correction device, and a control method therefor The present invention relates to a storage medium on which is recorded.

Conventionally, it has been proposed to use an optical device using a liquid lens for optical axis adjustment of an optical system (see Patent Document 1). The liquid lens used in the optical system seals the first liquid and the second liquid in a container, applies a voltage to an electrode provided in the container, and interfaces the first liquid and the second liquid. The shape is changed to change the optical characteristics.
JP 2002-55286 A

However, when a conventional liquid lens is driven by applying a voltage to an electrode provided in a container or a conductive liquid, the interface shape between the first liquid and the second liquid cannot be maintained at a desired interface shape. There is a problem.
The present invention has been made in view of the above-described problems of the prior art, and an optical device that makes it possible to maintain the desired interface shape between the first liquid and the second liquid, and the optical device. An object of the present invention is to provide a shake correction device using the apparatus, a camera system, an interchangeable lens, a mobile phone with a camera function, a control method of the shake correction device, and a storage medium recording the control method.

The optical device of the present invention is arranged in the container so as to face the first liquid so that the conductive or polar first liquid stored in the container does not mix with the first liquid. The conductive or polar second liquid stored, and the first liquid side surface and the second liquid side surface are disposed between the first liquid and the second liquid. at least one of comprises an optical element transparent is a curved surface, and said first liquid and said second liquid and the relative movement is allowed Ru metal contacts in accordance with the supplied electrical signal, before Symbol light optical element of It includes: the first liquid and shape of the interface between the second liquid is changed to have a stiffness which is not deformed even the inner wall surface of the outer periphery the container in a direction perpendicular to the optical axis of the optical element The optical axis is provided by a change in an interface shape between the first liquid and the second liquid. Characterized in that it moves in a direction perpendicular to.

Incidentally, before Symbol vessel, the first fluid and the second portion of the liquid is housed is a water-repellent,
The first liquid is hydrophilic, and the surface facing the second liquid is convex.
The second liquid is hydrophobic, and the surface facing the first liquid is concave;
Before Symbol Light optical element, the surface of the first liquid side is concave, the surface of the second liquid side may be a convex shape.
The surface of the pre-Symbol light optical element may have an affinity for the first liquid or the second liquid.
The front Symbol least one of the first surface and the surface of the second liquid side of the liquid side of the light optical element may have a spherical shape.

The front Symbol light optical element, said first liquid-side surface and the second surface of the liquid-side may have different shapes.
The refractive index of the first liquid and the refractive index of the second liquid may be different.

The refractive index of the previous SL light optical element may be different from either one of at least the first refractive index and the refractive index of the second liquid in the liquid.
The refractive index of the previous SL light optical element may be the first intermediate value of refractive index of the refractive index second liquid in the liquid.

Further, when the electrode unit drives the front Symbol light optical element, the focal length of the optical device may be unchanged.
The blur correction device of the present invention detects a blur amount perpendicular to the optical axis direction of the optical device described above and the optical device, and outputs a blur detection signal corresponding to the detected blur amount. A detection unit and a calculation unit that calculates a correction amount for correcting image blur based on the blur detection signal and outputs the electrical signal are provided.

The camera system of the present invention is equipped with the above-described blur correction device.
The interchangeable lens of the present invention is characterized by mounting the above-described blur correction device.
A mobile phone with a camera function according to the present invention is characterized in that the above-described blur correction device is mounted in an optical system.

  According to the present invention, when a physical signal is input between the first liquid and the second liquid and the transparent optical element is driven, an interface shape between the first liquid and the second liquid is desired. Provided is an optical device capable of maintaining an interface shape, a shake correction device using the optical device, a camera system, an interchangeable lens, a mobile phone, a control method for the shake correction device, and a storage medium recording the control method can do.

Hereinafter, embodiments shown in the accompanying drawings will be described. In this embodiment, a transparent optical element is used in order to define the interface shape between the first liquid and the second liquid.
(Description of optical device)
1-3 is explanatory drawing which shows operation | movement of the optical apparatus provided with the transparent optical element in this embodiment.

The optical device 120 shown in FIG. 1 includes a conductive liquid (high refractive index) 1, a dielectric liquid (low refractive index) 2, a container 5, an insulating layer 6, upper electrodes 7a and 8a, and a lower electrode 7b. 8b and the transparent optical element 13. Here, the upper electrode 7a and the lower electrode 7b, and the upper electrode 8a and the lower electrode 8b each constitute a pair of electrodes, and a DC voltage is applied as described later.
The conductive liquid 1 is, for example, an aqueous solution of an inorganic salt, and the dielectric liquid 2 is, for example, a fluorinated oil, and is configured so that the interface does not mix. Moreover, the water repellent finish is given to the inner side surface of the container 5, and therefore the conductive liquid 1 has a convex spherical shape.

  In this embodiment, the lower surface of the transparent optical element 13 has affinity for the conductive liquid 1, and the upper surface of the transparent optical element 13 has affinity for the dielectric liquid 2. Actually, it is sufficient that the lower surface of the transparent optical element 13 has an affinity for the conductive liquid 1 or the upper surface of the transparent optical element 13 has an affinity for the dielectric liquid 2. Here, affinity means the property that a certain substance easily binds to another substance.

FIG. 2 is a diagram showing a state when a DC voltage is applied between the upper electrode 8a and the lower electrode 8b. The application of the DC voltage changes the interface between the conductive liquid 1 and the dielectric liquid 2, and the conductive liquid 1 is displaced toward the electrode 8b as shown in FIG. This corresponds to a state in which a normal optical anti-vibration lens (not shown) has shifted to correct blurring. At this time, since the transparent optical element 13 is sandwiched between the conductive liquid 1 and the dielectric liquid 2, the interface shape can be kept constant. “Also, the transparent optical element 13 of the present embodiment is formed of a colorless and transparent polycarbonate resin. Even if the interface shape between the conductive liquid 1 and the dielectric liquid 2 changes, the transparent optical element 13 Therefore, the interface can be moved in the direction perpendicular to the optical axis direction while maintaining the interface shape of both the conductive liquid 1 and the dielectric liquid 2, and the in-focus state can be maintained. In this embodiment, the transparent optical element 13 is made of polycarbonate resin, but it is made of acrylic resin, urethane resin, organic glass, inorganic glass, or the like. Alternatively, the surface may be anti-reflective treated by coating. "
Moreover, it is preferable that at least one of the upper surface or the lower surface of the transparent optical element 13 has a spherical shape. That is, the transparent optical element 13 having a spherical shape can move the transparent optical element 13 more smoothly.

Furthermore, it is preferable that the surface of the transparent optical element 13 in contact with the conductive liquid 1 and the surface in contact with the dielectric liquid 2 have different shapes. Thereby, the refractive index of the transparent optical element 13 is determined.
Further, the refractive index of the transparent optical element 13 is preferably different from at least one of the refractive index of the conductive liquid 1 and the refractive index of the dielectric liquid 2. Thereby, the refractive power of the transparent optical element 13 is determined.

Further, the transparent optical element 1 preferably has an intermediate value between the refractive index of the conductive liquid 1 and the refractive index of the dielectric liquid 2. Thereby, reflection can be reduced and transmittance can be increased.
Further, when the transparent optical element 13 is driven, the transparent optical element 13 moves in the direction perpendicular to the optical axis, so that the focal length of the optical device 120 remains unchanged.
Further, the optical device 120 described above is provided in at least a part of the optical system, and is positioned at the interface in a direction perpendicular to the optical axis of the optical device 120 by an angular velocity detection signal (blur detection signal) output from an angular velocity sensor (not shown). The blur correction device can be configured by shifting the transparent optical element 13.

Since the transparent optical element 13 has a mass, the offset value of the DC voltage applied to the electrodes 8a, 8b, etc. is determined in advance in consideration of the movement of the transparent optical element 13 due to gravity. Thereby, the movement amount of the transparent optical element 13 can be accurately controlled.
1 and 2 show only the operation in the X-axis (one axis) direction. However, actually, an operation in a plane perpendicular to the optical axis (X axis and Y axis) is required.

  FIG. 3 is a view of the optical device 120 as viewed from above the optical axis. As shown in the figure, the electrode (circumferential shape) of the optical device 120 is divided into four, and four pairs of electrodes 7 (7a, 7b), 8 (8a, 8b), 9 (9a, 9b), 10 (10a, 10b), and control was possible in two axial directions in a plane perpendicular to the optical axis. That is, the optical device 120 is controlled by the electrodes 7 and 8 in the horizontal direction (X direction) on the paper surface and by the electrodes 9 and 10 in the vertical direction (Y direction) on the paper surface. Note that the minimum number of electrodes for effectively driving the optical device 120 is three pairs of electrodes.

In addition, when it is necessary to control the optical device 120 with high accuracy to correct blurring, the number of electrode divisions may be increased.
According to the above configuration, since the electrodes are very thin, it is possible to provide a miniaturized optical device and shake correction device.
In this embodiment, the electrodes 7a, 7b, 8a, and 8b are provided. However, a voltage may be directly applied to the conductive liquids 1 and 2.
(Application to camera system)
FIG. 4 shows an application of the optical device 120 of the present embodiment as a lens shift system blur correction device of a camera system. Specifically, a shake correction device is mounted in the interchangeable lens 200.

As shown in the figure, the camera system includes an interchangeable lens 200 and a camera body 210.
The interchangeable lens 200 includes an angular velocity sensor 15, an amplification unit 20, an A / D conversion unit 30, a basic value calculation unit 40, a subtractor 50, a target drive value calculation unit 60, a drive amount data table 70, The imaging magnification information calculation unit 90, the shooting distance information calculation unit 100, the blur correction lens optical information calculation unit 110, the ROM 115, the driver 80, and the optical device 120 for image blur correction are configured.

In the optical device 120, at least three pairs of electrodes are necessary, but for convenience of explanation, the optical device shown in FIG. 1 (two pairs of electrodes) is used. The basic value calculator 40, the subtractor 50, the target drive value calculator 60, the drive amount data table 70, the shooting magnification information calculator 90, the shooting distance information calculator 100, the blur correction lens optical information calculator 110, and the ROM 115 As shown in the figure, the microcomputer 150 is configured. The ROM 115 stores a control method (control procedure) of the microcomputer 150. The camera body 210 includes a quick return mirror 300, an amplification type imaging device 400 such as a CCD or CMOS, an optical finder 500, and the like.
(Operation of image stabilizer)
The angular velocity sensor 15 detects vibration applied to the camera system as an angular velocity, and outputs an angular velocity detection signal corresponding to the detected angular velocity. As the angular velocity sensor 15, a piezoelectric vibration type angular velocity sensor that normally detects Coriolis force is used.

  The amplifying unit 20 amplifies the angular velocity detection signal output from the angular velocity sensor 15. The output of the angular velocity sensor 10 is small. For this reason, even if the A / D converter 30 digitizes and attempts to process in the microcomputer, the resolution of the angular velocity detection signal is too low (that is, the angular velocity detection signal per bit is too large). For this reason, accurate vibration detection cannot be performed as it is, and the accuracy of image blur correction cannot be increased. Therefore, the amplification unit 20 amplifies the angular velocity detection signal before inputting it to the A / D conversion unit 30. Thereby, the resolution of the angular velocity detection signal in the microcomputer 150 can be increased (the angular velocity detection signal per bit is reduced), and the blur correction accuracy can be increased. In addition, the amplifying unit 20 may include a low-pass filter or the like in order to reduce high-frequency noise included in the output of the angular velocity sensor 15 as well as amplify the angular velocity detection signal. The amplified angular velocity detection signal is transmitted to the A / D converter 30.

  The A / D converter 30 converts the analog angular velocity signal sent from the amplifier 20 into a digital signal. By converting the angular velocity detection signal into a digital signal, arithmetic processing in the microcomputer 150 can be performed. The A / D conversion unit 30 may be provided separately from the microcomputer 150 as shown in FIG. 4, or when the A / D conversion unit is built in the microcomputer 150, the A / D conversion unit May be used.

The angular velocity detection signal is converted from an analog signal to a digital signal by the A / D conversion unit 30 and then input to the reference value calculation unit 40 and the subtracter 50.
The reference value calculation unit 40 calculates a reference value of the angular velocity detection signal when there is no shake based on the angular velocity detection signal. That is, the reference value calculation unit 40 outputs the angular velocity detection signal when the shake is zero to the subtracter 50 as a reference value.

  As an example of a reference value calculation method in the reference value calculation unit 40, there is a moving average shown in the following (Equation 1).

この他、一般的なローパスフィルタを利用して基準値を算出してもよい。例えば、増幅部２０とＡ／Ｄ変換部３０の間にローパスフィルタを設けてもよい。
減算器５０は、Ａ／Ｄ変換部３０から出力される角速度検出信号から前記基準値を減算して角速度で表される振れ検出信号を求め、求めた振れ検出信号を目標駆動値演算部６０へ出力する。

In addition, the reference value may be calculated using a general low-pass filter. For example, a low-pass filter may be provided between the amplification unit 20 and the A / D conversion unit 30.
The subtracter 50 subtracts the reference value from the angular velocity detection signal output from the A / D conversion unit 30 to obtain a shake detection signal represented by the angular velocity, and sends the obtained shake detection signal to the target drive value calculation unit 60. Output.

  The target drive value calculation unit 60 converts the shake detection signal represented by the angular velocity into shake angle information by time integration. Thereafter, the target drive value calculator 60 includes the shake angle information, the shooting magnification information β calculated by the shooting magnification information calculator 90, the focal length information R of the lens calculated by the shooting distance information calculator 100, Target drive value information for driving the optical device 120 is calculated using the blur correction lens optical information (blur correction coefficient K) calculated by the blur correction lens optical information calculation unit 110.

That is, the photographing magnification information calculation unit 90 calculates the photographing magnification information β from the focal length of the photographing magnification information optical system, the position of the focus adjustment lens, and the like. The calculated photographing magnification information β is input to the target drive value calculation unit 60.
The shooting distance information calculation unit 100 calculates shooting distance information R from the focal length of the shooting distance information optical system, the position of the focus adjustment lens, and the like. The shooting distance information R is input to the target drive value calculation unit 60.

The blur correction lens optical information calculation unit 110 inputs optical information related to the blur correction lens to the target drive value calculation unit 60. The optical information here is the blur correction coefficient K as described above. The definition of the blur correction coefficient K is blur correction coefficient = image movement amount with respect to lens movement amount.
An example of an arithmetic expression for target drive value information is shown in the following (Equation 2).

（数２）は、レンズ目標駆動値θとＡ／Ｄ変換部３０から出力される角速度検出信号との偏差を求め（減算器５０の働き）、それをもとにして光学装置１２０を駆動するための駆動信号を演算するものである。駆動信号の演算は、偏差に比例する項、偏差の積分に比例する項、偏差の微分に比例する項を足しあわせる形で駆動信号を演算するＰＩＤ制御が一般的である。しかし、ＰＩＤ制御に限らず、他の方法を用いてもよい。

(Equation 2) calculates the deviation between the lens target drive value θ and the angular velocity detection signal output from the A / D converter 30 (operation of the subtractor 50), and drives the optical device 120 based on the deviation. The drive signal for calculating is calculated. The calculation of the drive signal is generally PID control in which the drive signal is calculated by adding a term proportional to the deviation, a term proportional to the integral of the deviation, and a term proportional to the derivative of the deviation. However, the method is not limited to PID control, and other methods may be used.

The drive signal output from the target drive value calculation unit 60 is input to the drive amount data table 70. The drive amount data table 70 takes the drive signal (digital signal) output from the target drive value calculation unit 60 into the drive of the optical device 120 in consideration of the optical axis shift amount of the optical device 120 and the shift amount in the optical axis direction. It is converted into a voltage and output to the driver 80.
The driver 80 receives the drive voltage output from the drive amount data table 70, converts the voltage into voltages applied to the upper electrode 7a, the lower electrode 7b, the upper electrode 8a, and the lower electrode 8b, and outputs them.

As shown in FIG. 4, the optical device 120 is built in the imaging optical system of the photographing unit, and the transparent optical element 13 located at the interface between the conductive liquid 1 and the dielectric liquid 2 is substantially orthogonal to the optical axis. It is comprised so that it can move to the direction to do (refer FIGS. 1-3).
The transparent optical element 13 located at the interface between the conductive liquid 1 and the dielectric liquid 2 is appropriately adjusted in a direction substantially orthogonal to the optical axis by the voltage applied to the upper electrode 7a, the lower electrode 7b, the upper electrode 8a, and the lower electrode 8b. Driven to deflect the optical axis of the imaging optical system. Image blur such as a photograph occurs when an image on the imaging surface moves during exposure due to vibration applied to the camera such as camera shake. However, a camera with a shake correction apparatus as shown in FIG. 4 includes a vibration detection sensor such as the angular velocity sensor 15. These vibration detection sensors detect vibration applied to the camera system. If the vibration applied to the camera system is detected, the movement of the image on the imaging surface can be known. Therefore, the optical device 120 is operated so that the movement of the image on the imaging surface stops, and the imaging surface The movement of the upper image, that is, the image blur can be corrected.

In the above embodiment, the angular velocity sensor 15 is used. However, the present invention is not limited to this, and an acceleration sensor, for example, may be used instead of the angular velocity sensor 15.
Note that the microcomputer 150 includes all the non-volatile memory that stores various information such as the arithmetic unit, the conversion unit, and the control program described above. Further, the camera system may be an interchangeable lens type or may be an integral lens that cannot be interchanged.

Further, as shown in FIG. 5, the present invention can be applied to a lens system L of a mobile phone having a camera function. That is, by applying to the lens system L of a mobile phone, it is possible to provide a mobile phone having a camera function capable of blur correction.
(Specific examples of image blur correction)
Hereinafter, a specific example of correcting the image blur by controlling the optical device will be described.

FIG. 6 shows a shake correction apparatus according to the present embodiment. The parts described in FIG. The optical system of this embodiment includes optical system groups 21 and 22 that do not shift with respect to the optical axis, and an optical device 120 that shifts with respect to the optical axis.
FIG. 6 shows a state in which the optical axis of each optical system group is substantially coaxial, and the image plane at that time is 31.

FIG. 7 shows a state in which the voltage output from the driver 80 shown in FIG. 4 is applied between the upper electrode 7a and the lower electrode 7b and between the upper electrode 8a and the lower electrode 8b of the optical device 120 in this embodiment. ing. The configuration of the lens system is the same as in FIG.
In this specific example, in the optical device 120, since the transparent optical element 13 is located at the interface between the conductive liquid (high refractive index) 1 and the dielectric liquid (low refractive index) 2, the shape of the interface can be kept constant. It becomes possible. Therefore, as shown in FIG. 7, the position of the image plane 33 can be made substantially the same position (in focus) as the image plane 31 shown in FIG.

  INDUSTRIAL APPLICABILITY The present invention is greatly utilized industrially in the fields of an optical device, a shake correction device, a camera system equipped with a shake correction device, an interchangeable lens equipped with a shake correction device, and a camera-equipped mobile phone equipped with a shake correction device. Can do.

It is explanatory drawing which shows an optical apparatus. It is explanatory drawing which shows an optical apparatus. It is explanatory drawing which shows an optical apparatus. It is a block diagram showing the basic composition of the camera provided with the blurring correction apparatus. It is explanatory drawing which shows an example of the mobile phone with a camera function. It is explanatory drawing which shows the specific example which controls an optical apparatus and correct | amends image blur. It is explanatory drawing which shows the specific example which controls an optical apparatus and correct | amends image blur.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Conductive liquid, 2 ... Dielectric liquid, 5 ... Container, 6 ... Insulating layer, 7a, 7b ... Upper electrode, 8a, 8b ... Lower electrode, 13 ... Transparent optical element, 15 ... Angular velocity sensor, 20 ... Amplifying part , 30 ... A / D converter, 40 ... basic value calculator, 50 ... subtractor, 60 ... target drive value calculator, 70 ... drive amount data table, 80 ... driver, 90 ... photographing magnification information calculator, 100 ... Shooting distance information calculation unit 110... Shake correction lens optical information calculation unit 115 115 ROM 120 Optical device 200 Interchangeable lens 210 Camera body L Lens system (mobile phone)

Claims (13)

A conductive or polar first liquid contained in a container ;
A conductive or polar second liquid stored in the container so as to face the first liquid so as not to mix with the first liquid;
A transparent optical element disposed between the first liquid and the second liquid, wherein at least one of the first liquid side surface and the second liquid side surface is a curved surface;
According to the supplied electric signal and a first liquid and the second liquid and the relative movement is allowed Ru metal contacts,
Before Symbol Light optical element may have a rigidity interface shape is not deformed even when changing between the first liquid and the second liquid, the outer peripheral in the direction perpendicular to the optical axis of the optical element An optical device , which is provided at a distance from an inner wall surface of the container and moves in a direction perpendicular to the optical axis due to a change in an interface shape between the first liquid and the second liquid . The optical device according to claim 1,
Before SL vessel, the first fluid and the second portion of the liquid is housed is a water-repellent,
The first liquid is hydrophilic, and the surface facing the second liquid is convex.
The second liquid is hydrophobic, and the surface facing the first liquid is concave;
Before Symbol Light optical element, said a first liquid-side surface is concave, optical and wherein the surface of said second liquid side has a convex shape. The optical device according to claim 1 or 2,
Optical apparatus, wherein at least one of a spherical shape of the first surface and the surface of the second liquid side of the liquid side of the front Symbol light optical element. The optical device according to any one of claims 1 to 3, wherein
Before Symbol Light optical element is an optical device which comprises said first liquid-side surface and the second liquid-side surface and are different shapes. The optical device according to any one of claims 1 to 4, wherein:
An optical device, wherein a refractive index of the first liquid and a refractive index of the second liquid are different. The optical device according to any one of claims 1 to 5, wherein:
Before SL refractive index of the light optical element, the optical apparatus characterized by different at least the one of the refractive index of the first and the second liquid and the refractive index of the liquid. The optical device according to claim 6.
The refractive index of the previous SL light optical element, an optical device, characterized in that said a first intermediate value of refractive index of the refractive index second liquid in the liquid. The optical device according to any one of claims 1 to 7,
When the electrode unit drives the front Symbol light optical element, an optical device, wherein a focal length of said optical device is unchanged. The optical device according to any one of claims 1 to 8,
Surface prior Symbol light optical element, the optical apparatus characterized by having an affinity for the first liquid or the second liquid. An optical device according to any one of claims 1 to 9,
A blur detection unit that detects a blur amount in a direction perpendicular to the optical axis direction of the optical device and outputs a blur detection signal according to the detected blur amount;
A blur correction apparatus comprising: a calculation unit that calculates a correction amount for correcting image blur based on the blur detection signal and outputs the electrical signal.   A camera system comprising the blur correction device according to claim 10.   An interchangeable lens comprising the blur correction device according to claim 10.   A mobile phone with a camera function, wherein the blur correction device according to claim 10 is mounted in an optical system.

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