JP2007158588A - Imaging system and focusing position correction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging system provided with a mechanism of correcting the effect of the eccentricity of an optical element and for suppressing the manufacturing cost. <P>SOLUTION: The imaging system includes: a movable optical element for changing a direction of transmission object light by being moved within a two-dimensional plane in crossing with the direction of the object light; a high polymer actuator comprising a high polymer membrane for connecting the movable optical element to a support member for supporting the movable optical element, and extended/contracted through the application of a voltage, and a plurality of electrodes separately arranged on the surface of the high polymer membrane; an image signal generating section for generating an image signal; an imaging apparatus including a connection unit to which a focusing position correction unit for correcting a deviation of a focusing position is removably loaded; and a focusing position correction unit provided with a deviation correction section that applies a voltage in response to a deviation amount of the focusing position of the object light to the movable optical element to move the movable optical element within the two-dimensional plane thereby correcting the deviation in the object light. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging system and an imaging position correction method for correcting a shift in an imaging position of subject light when an image signal representing a subject image is generated by imaging subject light.

  In recent years, imaging devices represented by digital cameras and technologies related to various elements constituting such imaging devices have been developed. Among the components of such an imaging device, an optical system provided with an optical element such as a lens and an imaging system provided with an imaging element such as a CCD generate an image signal by forming an image of subject light. It plays an important role, and is a component that requires high-precision functions.

  In the manufacturing process of the imaging device, the position of such an optical element and the imaging device is attached to the imaging device in a state slightly deviated from the position where it should originally be attached, and the relative position of the optical element with respect to the imaging device. A so-called decentration of the optical element, which causes a shift, may occur. In this state, a problem such as a shift in the imaging position of the subject light occurs, resulting in a problem that the image shift appears in the captured image.

Recently, a method for calculating the amount of such eccentricity from image data obtained by photographing (see, for example, Patent Document 1) and a mechanism for incorporating a mirror into an optical system and changing the shape of the mirror are provided. A method for correcting the influence of eccentricity is proposed (for example, see Patent Document 2).
JP 2005-49598 A JP 2003-287612 A

  However, in this method, even if a mechanism for changing the mirror shape is provided in the imaging apparatus, the mechanism becomes useless after the adjustment, which only increases the manufacturing cost of the imaging apparatus and is not advantageous. .

  In view of the above circumstances, an object of the present invention is to provide an imaging system and an imaging position correction method that include a mechanism that corrects the influence of eccentricity of an optical element, and that suppresses manufacturing costs.

In order to achieve the above object, an imaging system of the present invention comprises:
An imaging device that forms subject light and generates an image signal representing the subject image, and is detachably attached to the imaging device, and controls the imaging device to correct the deviation of the imaging position of the subject light. In an imaging system comprising an imaging position correction unit that
A movable optical element that changes the direction of the transmitted subject light by transmitting the subject light and moving in a two-dimensional plane intersecting the direction of the subject light;
A polymer film that connects the movable optical element and a support member that is disposed apart from the movable optical element and supports the movable optical element, and that expands and contracts upon application of a voltage; and A polymer actuator comprising a plurality of electrodes that are arranged in contact with each other on the surface of the polymer film and that partially apply a voltage to the polymer film;
An imaging apparatus comprising: a connection portion to which the imaging position correction unit is detachably attached; and recognizing the amount of deviation of the imaging position of subject light, and applying a voltage corresponding to the amount of deviation An imaging position correction unit including a shift correction unit that corrects a shift in the imaging position of subject light by moving the movable optical element in the two-dimensional plane;
It is provided with.

  The imaging system of the present invention corrects the imaging position by moving the movable optical element in a two-dimensional plane intersecting the direction of subject light only by applying a voltage to the polymer actuator. Since the mechanism for correcting the imaging position is simple as described above, and the polymer actuator is relatively inexpensive, the imaging system of the present invention can reduce the manufacturing cost.

  In the imaging system of the present invention, the form “the movable optical element is a lens” is a preferred form.

  According to such a configuration, the lens is driven only by applying a voltage to the polymer actuator, and the imaging position can be easily corrected.

  Further, in the imaging system of the present invention and the imaging system of the present invention in which the movable optical element is a lens, “from a light transmissive material bonded to a transmission surface of the movable optical element through which subject light is transmitted. A form in which at least a part of the film-like part excluding the part bonded to the movable optical element is provided with an optical film integrally connected to the polymer film is also a preferable form.

  According to such a form, the configuration is simplified without requiring a holder for supporting the movable optical element.

  In the imaging system of the present invention, “the imaging device includes an image signal generation unit that generates an image signal upon receiving irradiation of subject light transmitted through the movable optical element. A deviation amount calculation unit that calculates the amount of deviation of the imaging position of the subject light from the image signal is provided, and the deviation correction unit acquires the amount of deviation calculated by the deviation amount calculation unit. The form of “recognizing the amount of deviation by this” is also a preferable form.

With such a form, the amount of deviation of the imaging position of the subject light is calculated from the image signal,
The imaging position can be easily corrected.

  Further, in the imaging system of the present invention, a mode that “the shift correction unit applies a voltage having a magnitude corresponding to the shift amount” is a preferable mode.

  According to such a form, an appropriate amount of voltage is applied to the polymer actuator in accordance with the amount of deviation of the imaging position, thereby correcting the deviation of the imaging position.

  In the imaging system of the present invention, a form in which “the deviation correction unit applies a pulse voltage having a pulse width corresponding to the amount of deviation” is also a preferable form.

Many polymer actuators have a slow response to the applied voltage. For such polymer actuators, using a pulse that is much shorter than the response time causes the pulse voltage to be leveled out in the response time, and is effectively constant. The same effect as the application of voltage can be produced. Furthermore, the effective constant voltage can be changed by changing the pulse width.
Therefore, according to the above-described embodiment, an appropriate amount of voltage is effectively applied to the polymer actuator in accordance with the amount of deviation of the imaging position, thereby correcting the deviation of the imaging position.

  In the imaging system of the present invention, “the imaging apparatus includes a position fixing unit that fixes the movable optical element at a position of the movable optical element when the shift of the imaging position is corrected by the shift correction unit. The “provided” form is also a preferred form.

  According to such a configuration, even after voltage control on the polymer actuator is stopped, the movable optical element can be fixed at an appropriate position in which the deviation of the imaging position is corrected. In addition, after the position of the movable optical element is fixed, the polymer actuator is not required. However, since the polymer actuator is generally elastic, when the imaging device is used, the imaging device is impacted from the outside. Even when added, the polymer actuator functions as a damper and has an effect of reducing damage to the movable optical element.

Further, in the imaging system of the present invention or the imaging system of the present invention that applies a pulse voltage, “when the polymer film is applied with a variable voltage, it depends on an average voltage of the variable voltage. The form of “expandable and contractable” is also a preferable form.

  With this configuration, even if the applied voltage fluctuates, the deviation of the imaging position can be easily corrected by setting the average voltage to an appropriate amount of voltage according to the deviation of the imaging position. The

  Further, in the imaging system of the present invention, “the polymer film expands in response to release of the applied voltage, and the shift correction unit replaces voltage application to the plurality of electrodes, The form of “controlling the voltage by applying and releasing the voltage to a plurality of electrodes” is also a preferable form.

  With this configuration, the image position shift can be easily corrected by applying and releasing an appropriate amount of voltage according to the image position shift.

In order to achieve the above object, the imaging position correction method of the present invention comprises:
In an imaging position correction method for correcting a shift in the imaging position of subject light in an imaging device that forms subject light and generates an image signal representing the subject image,
A shift amount recognition process for recognizing the shift amount of the imaging position of the subject light,
A movable optical element that transmits the subject light and moves in a two-dimensional plane intersecting the direction of the subject light to change the direction of the transmitted subject light, and the movable optical element that is disposed apart from the movable optical element A polymer film that is connected to a support member that supports an element and expands and contracts when a voltage is applied, and the polymer film that is divided and disposed on the surface of the polymer film in contact with the polymer film For a polymer actuator comprising a plurality of electrodes for partially applying a voltage to the plurality of electrodes, a voltage corresponding to the amount of displacement recognized by the displacement amount recognition process is applied to the electrodes. A shift correction process for correcting a shift in the imaging position of the subject light by moving the movable optical element in the two-dimensional plane;
A position fixing process for fixing the movable optical element to the position of the movable optical element when the shift of the imaging position is corrected by the shift correction process.

  In the imaging position correction method of the present invention, the movable optical element moves in a two-dimensional plane intersecting the direction of the subject light only by applying a voltage to the polymer actuator, and the imaging position is corrected. The element is fixed at an appropriate position where the deviation of the imaging position is corrected. Since the mechanism for correcting the imaging position is simple as described above, and the polymer actuator is relatively inexpensive, the manufacturing cost can be reduced by the imaging position correction method of the present invention. In addition, after the position of the movable optical element is fixed, the polymer actuator is not required. However, since the polymer actuator is generally elastic, when the imaging device is used, the imaging device is impacted from the outside. Even when added, the polymer actuator functions as a damper and has an effect of reducing damage to the movable optical element.

  According to the present invention, the influence of the eccentricity of the optical element can be corrected and the manufacturing cost can be reduced.

[First Embodiment]
The first embodiment of the present invention will be described below.

  FIG. 1 is an external perspective view of a digital camera that is a first embodiment of an imaging apparatus included in the imaging system of the present invention.

  A digital camera 1 shown in FIG. 1 is provided with a photographing lens 10 that collects subject light, a flash light emitting unit 12 that emits flash light, and a finder objective window 13. A shutter button 14 is provided.

  On the rear surface (not shown) of the digital camera 1, various switches such as a zoom operation switch and a cross key, and an LCD (liquid crystal display) for displaying images and menu screens are provided.

  FIG. 2 is a diagram illustrating a schematic internal configuration of the digital camera 1 illustrated in FIG. 1 and a schematic internal configuration of an eccentricity correction apparatus connected to the digital camera 1.

  In the digital camera 1 of the present embodiment, all processes are controlled by the CPU 120. The CPU 120 includes various switches provided in the digital camera 1 (the various switches include the shutter button 14 shown in FIG. 1, a zoom operation switch, a cross key, and the like. Operation signals from the group 101 are supplied. The CPU 120 has a ROM 110a, and various programs necessary for executing various processes by the digital camera 1 are written in the ROM 110a. When a power switch (not shown) included in the switch group 101 is turned on, power is supplied from the power source 102 to various elements of the digital camera 1, and the entire digital camera 1 is executed by the CPU 120 according to the program procedure written in the ROM 110a. Is controlled centrally.

  Hereinafter, the configuration of the digital camera 1 will be described along the flow of image signals.

  The subject light indicated by the alternate long and short dash line in the figure passes through the photographing lens 10 composed of a plurality of lenses and the diaphragm 30 and forms an image on the CCD 40, and an image signal representing the subject image is generated in the CCD 40.

  In the manufacturing process of the image pickup device, the lens and the CCD are attached to the image pickup device with a slight shift, and as a result, a so-called lens eccentricity occurs in which the lens is displaced relative to the CCD. Sometimes. The photographing lens 10 also includes an eccentricity correction lens 20 for correcting the influence of such lens eccentricity. When correcting the decentration effect of the lens, as will be described later, the decentering correction lens 20 is perpendicular to the direction of the subject light by the action of the polymer actuator 500 provided beside the decentration correction lens 20. By moving in the plane, the influence of eccentricity is corrected. This eccentricity correction work is performed by connecting the digital camera 1 with an eccentricity correction device 520 having components within the dotted line in the figure.

  The generated image signal is roughly read out by the A / D unit 131, the analog signal is converted into a digital signal, and low resolution through image data is generated. The generated through image data is subjected to image processing such as white balance correction and γ correction in a white balance / γ processing unit 133. Here, a timing signal is supplied from the clock generator 132 to the CCD 40, and an image signal is generated at predetermined intervals in synchronization with the timing signal. The clock generator 132 outputs a timing signal based on an instruction from the CPU 120 transmitted via the optical CPU 120. The timing signal is output from the CCD 40, the A / D unit 131 in the subsequent stage, and the white balance / γ. It is also supplied to the processing unit 133. Therefore, the CCD 140, the A / D unit 131, and the white balance / γ processing unit 133 perform the processing of the image signals in order in synchronization with the timing signal generated from the clock generator 132.

  The image data subjected to the image processing in the white balance / γ processing unit 133 is temporarily stored in the buffer memory 134. The low-resolution through image data stored in the buffer memory 134 is supplied to the YC / RGB conversion unit 138 via the bus 140 first from the through image data stored at the old time. Since the through image data is an RGB signal, the YC / RGB conversion unit 138 does not perform processing, but directly transmits the image to the image display LCD 160 via the driver 139, and the through image represented by the through image data is displayed on the image display LCD 160. Is displayed. Here, in the CCD 140, since the subject light is read at every predetermined timing and an image signal is generated, the subject in the direction in which the photographing lens is directed is always displayed as a subject image on the image display LCD 160. . The through image data stored in the buffer memory 134 is also supplied to the CPU 120, and the CPU 120 performs autofocus processing and automatic exposure adjustment based on the through image data.

  Here, when the photographer presses the shutter button 14 shown in FIG. 1 while confirming the through image displayed on the image display LCD 160, the CPU 120 is notified that the shutter button 14 has been pressed. When the subject is dark, the CPU 120 transmits a light emission instruction to the flash light emitting unit 12, and a flash light is emitted from the flash light emitting unit 12 in synchronization with the pressing of the shutter button 14. When the shutter button 14 is pressed and shooting is performed, the image signal generated by the CCD 40 is finely read by the A / D unit 131 in accordance with an instruction from the CPU 120, and high-resolution captured image data is generated. The generated captured image data is subjected to image processing by the white balance / γ processing unit 133 and stored in the buffer memory 134. The captured image data stored in the buffer memory 134 is supplied to the YC processing unit 137 and converted from RGB signals to YC signals. The captured image data converted into the YC signal is subjected to compression processing in the compression / decompression unit 135, and the compressed captured image data is stored in the memory card 170 via the I / F 136. The captured image data stored in the memory card 170 is subjected to decompression processing in the compression / decompression unit 135, converted into RGB signals in the YC / RGB conversion unit 138, and then displayed on the image display LCD 160 via the driver 139. Reportedly. On the image display LCD 160, a captured image represented by the captured image data is displayed.

  The digital camera 1 also includes a camera-side connector 510a that is connected to the device-side connector 510b of the eccentricity correction device 520, and the eccentricity correction operation is performed using the device-side connector 510b and the camera-side connector 510a. This is done by connecting The eccentricity correction device 520 includes an arithmetic unit 504 that calculates an amount of eccentricity representing the amount of deviation of the imaging position of the subject light from the image data, and a voltage adjustment unit 503 that adjusts the voltage applied to the polymer actuator 500. And a controller 505 that controls the voltage adjustment unit 503 by obtaining a voltage necessary for driving the polymer actuator 500 from the calculation result of the calculation unit 504. The captured image data stored in the buffer memory 134 is supplied to the calculation unit 504 via the camera-side connector 510a and the device-side connector 510b and used for calculating the amount of eccentricity. The eccentricity is corrected by moving the eccentricity correction lens 20 in a plane perpendicular to the direction of the subject light by a mechanism described later. Here, the decentering correction device 520 corresponds to an example of an imaging position correction unit according to the present invention, and the camera-side connector 510a corresponds to an example of a connection portion according to the present invention.

  The digital camera 1 and the eccentricity correction device 520 are configured as described above.

  The digital camera 1 has a mechanism for correcting the eccentricity of the lens by being connected to the eccentricity correction device 520 even if the lens is eccentric. Hereinafter, a mechanism and a configuration for correcting this eccentricity will be described.

  FIG. 3 is a diagram showing the decentration correction lens shown in FIG. 2 and a mechanism for driving the decentration correction lens.

  In order to drive the eccentricity correction lens 20 shown in FIG. 2, the digital camera 1 has a square shape with a circular hole in the center so as to surround the circular holder 506 that supports the eccentricity correction lens 20. A polymer actuator 500 is provided. Further, an outer frame 507 for fixing the outer end of the polymer actuator 500 is provided around the polymer actuator 500. Here, the combination of the decentering correction lens 20 and the holder 506 corresponds to an example of a movable optical element according to the present invention, and the outer frame 507 corresponds to an example of a support member according to the present invention.

  The polymer actuator 500 includes electrodes 502a, 502b, 502c, and 502d and a dielectric elastomer 501 that is a type of polymer material that expands and contracts in response to voltage application. The electrodes 502a, 502b, 502c, and 502d are electrodes each formed by bonding a highly conductive carbon fiber on a dielectric elastomer 501, and an upper surface of the polymer actuator 500 and a lower side (not shown). There are four each on the surface. The upper four electrodes are anodes, the lower four electrodes are cathodes, and a set of anodes and cathodes constitutes four sets of electrodes. In this figure, of the four sets of electrodes 502a, 502b, 502c, and 502d, four anodes indicated by hatching provided on the upper surface are shown. The dielectric elastomer 501 has a shape surrounding the holder 506 and has a square shape with a circular hole in the center. This figure shows a state in which a part of the dielectric elastomer 501 is visible from between two adjacent electrodes among the four electrodes 502a, 502b, 502c, and 502d.

  With this configuration, in this polymer actuator 500, voltages of different magnitudes are applied to the dielectric elastomer 501 at each of the four portions sandwiched between the upper surface electrode and the lower surface electrode. Can be applied. Hereinafter, a mechanism for applying voltages of different magnitudes to these four parts will be described.

  FIG. 4 is a diagram illustrating a configuration for applying a voltage to four sets of electrodes included in the polymer actuator shown in FIG.

  As shown in the figure, four sets of electrodes 502a, 502b, 502c, and 502d and four voltage adjustment units 503a, 503b, 503c, and 503d are each set of electrodes and voltage adjustment units, and are connected in parallel to the power supply 102. Has been. The voltage adjustment unit 503 described with reference to FIG. 2 represents these four voltage adjustment units 503a, 503b, 503c, and 503d as a single voltage adjustment unit 503 for illustration. As shown in FIG. 4, there are four voltage adjustment units. The four voltage adjustment units 503a, 503b, 503c, and 503d have a role of adjusting voltages applied to the four sets of electrodes 502a, 502b, 502c, and 502d, and are individually controlled by the controller 505. With such a configuration, different voltages can be applied to the four sets of electrodes 502a, 502b, 502c, and 502d.

  In this embodiment, the voltage is received from the power source 102 as described above, but the present invention may use a high voltage supplied to the flash light emitting unit 12.

  FIG. 5 is a cross-sectional view of the decentration correction lens and polymer actuator shown in FIG.

  As shown in FIG. 5, the portion of the dielectric elastomer 501 sandwiched between the two electrodes 502c on the left side of the figure is applied with a voltage by the left electrode 502c, while the two electrodes on the right side of the figure A portion sandwiched between 502a is applied with a voltage by the right electrode 502a. This figure shows a state in which no voltage is applied, and therefore no expansion has occurred. Further, the outer frame 507 shown in this figure plays a role of fixing only the end of the polymer actuator 500 so that the polymer actuator 500 can freely expand and contract, and hereinafter, the structure of the outer frame 507 for fixing the same. Will be described.

  FIG. 6 is a view showing the structure of the outer frame shown in FIGS. 5 and 6 for fixing the end of the polymer actuator.

  As shown in this figure, the outer frame 507 shown in FIG. 5 is paired with a first presser plate 507a and a second presser plate 507b sandwiching the ends of the polymer actuator 500, and these first presser plates. In order to maintain the plate 507a and the second pressing plate 507b in close contact with each other, a screw 507c is used as a constituent element. The surface of the second pressing plate 507b that presses the polymer actuator 500 is provided with a convex portion 507d, and the surface of the second pressing plate 507b that presses the polymer actuator 500 mates with the convex portion 507d. It becomes the shape to do. In a state where the polymer actuator 500 is caught by the convex portion 507d, the first pressing plate 507a and the second pressing plate 507b are in close contact with the polymer actuator 500 interposed therebetween, and the state is maintained. The first pressing plate 507a and the second pressing plate 507b are attached to each other with the screws 507c.

  In this way, only the end of the polymer actuator 500 is firmly fixed with an extremely simple configuration.

  Next, the flow of work when eccentricity is corrected will be described using the configuration described above.

  FIG. 7 is a flowchart showing a work flow when eccentricity correction is performed.

  First, in order to inspect the eccentricity of the lens of the digital camera 1, the camera side connector 510 a shown in FIG. 2 that the digital camera 1 has and the device side connector 510 b that the eccentricity correction device 520 has are connected. Then, photographing using the digital camera 1 is performed on a light emitting body having a light emitting surface with a substantially uniform luminance distribution so that only the light emitting surface becomes a subject, and photographed image data is generated. The captured image data is temporarily stored in the buffer memory 134 shown in FIG. 2, and then input to the computing unit 504 in the eccentricity correction device 520 via the camera side connector 510a and the device side connector 510b (step S1). .

  In general, the amount of light decreases as the distance from the optical axis moves away from the optical axis on the light receiving surface on which the CCD 40 shown in FIG. 2 receives subject light. Therefore, if the optical axis of the photographing lens 10 deviates from the center position of the CCD 40 due to decentration, Variation (unbalance) occurs in the amount of light received at the periphery of the light receiving surface (for example, the four corners of the light receiving surface). Therefore, it is possible to evaluate the magnitude and direction of the eccentricity by analyzing the image data portion representing the subject light received at the periphery of the light receiving surface of the CCD 40. Therefore, the calculation unit 504 extracts, from the input captured image data, the captured image data portions generated by receiving light at each of the four corners of the light receiving surface of the CCD 40, and based on the relative brightness difference, the eccentricity is extracted. The amount of eccentricity representing the magnitude and direction of the is calculated (step S2). This amount of eccentricity represents a shift in the imaging position of the subject light by xy coordinates on a two-dimensional plane (xy plane) perpendicular to the direction of the subject light. When the eccentricity is small, the x-coordinate component and Both y-coordinate components are close to 0. Then, the amount of eccentricity is input to the controller 505, and it is determined whether or not the correction of the eccentricity is necessary depending on whether or not the degree of eccentricity (the length on the xy plane) is larger than a predetermined amount (step S3). ).

  In this embodiment, the calculation unit 504 in the eccentricity correction device 520 is configured to calculate the amount of eccentricity from the captured image data stored in the buffer memory 134 as described above. The image data processing unit, such as the white balance / γ processing unit 133, calculates the amount of eccentricity that also functions as the above-described calculation unit 504, and the amount of eccentricity obtained by the calculation is the eccentricity correction. A form of inputting to the controller 505 in the apparatus 520 may be adopted. Further, according to the present invention, the calculation unit 504 performs the photographic image data immediately after A / D conversion before being stored in the buffer memory 134 or the compression processing instead of the photographic image data stored in the buffer memory 134. A form in which the amount of eccentricity is calculated from the captured image data after that may be employed, and a form in which the amount of eccentricity is computed from the through image data instead of the photographed image data may be employed.

If it is determined that eccentricity correction is not necessary (step S3; No), the inspection of the eccentricity of the lens of the digital camera 1 ends here. If it is determined that eccentricity correction is necessary (step S3; Yes), then the controller 505 corrects the amount of eccentricity, and then the four electrodes of the polymer actuator 500 shown in FIGS. Of these, determination is made as to how much voltage is applied to which electrode (step S4). Then, in response to an instruction from the controller 505, the voltage adjustment unit 503 shown in FIG. 2 applies a voltage to the electrode determined in step S4, and the polymer actuator 500 is driven (step S5).
A combination of the controller 505 and the four voltage adjustment units 503a, 503b, 503c, and 503d corresponds to an example of a deviation correction unit according to the present invention.

  Here, a state in which a voltage is applied to the polymer actuator 500 to move the eccentricity correction lens 20 and the holder 506 will be described in detail. In the following, as an example, in order to correct the eccentricity, it is necessary to move the eccentricity correction lens 20 to the right side from the state of FIG. 5, and a voltage is applied between the two electrodes 502c on the left side shown in FIG. An explanation will be given assuming that is determined.

  FIG. 8 is a cross-sectional view of the decentration correction lens and polymer actuator, showing a state when a voltage is applied to the left electrode in the state of FIG.

  In general, a dielectric elastomer has a property that when a voltage is applied, the dielectric elastomer expands in a direction along the electrode to which the voltage is applied, and the amount of expansion increases as the applied voltage increases. When the dielectric elastomer 501 expands and contracts with the applied voltage, the four sets of electrodes 502a, 502b, 502c, and 502d expand and contract together with the expanded and contracted dielectric elastomer 501.

  When a voltage is applied between the two left electrodes 502c from the state shown in FIG. 5, the dielectric elastomer 501 sandwiched between the two left electrodes 502c is shown in FIG. To generate a driving force that pushes the eccentricity correcting lens 20 and the holder 506 to the right. The decentering correction lens 20 and the holder 506 pushed to the right side are illustrated as a whole while compressing the portion of the dielectric elastomer 501 sandwiched between the two electrodes 502a on the right side in FIG. It will move to the right side from the state shown in FIG. As a result, the eccentricity is corrected by this voltage application.

  By applying such a voltage to each part of the dielectric elastomer 501 sandwiched between the electrode on the upper surface and the electrode on the lower surface, the decentering correction lens 20 and the holder 506 are The eccentricity is corrected by moving in a plane perpendicular to the direction of the subject light.

  In the state shown in FIG. 8, the decentration correction lens only stays at the position shown in FIG. 8 due to the application of voltage to the polymer actuator 500. Even if the application of voltage is stopped, the decentration correction lens remains at this position. Therefore, a mechanism for fixing the position of the eccentricity correction lens 20 is required. Therefore, the digital camera 1 is provided with a fixing unit for fixing the position of the eccentricity correction lens 20. ing. After the decentering correction lens 20 is moved to a position necessary for decentration correction, an operation for fixing the position of the decentering correction lens 20 using this fixing portion is performed (step S6 in FIG. 7). .

  FIG. 9 is a diagram showing a mechanism for fixing the position of the decentration correction lens shown in FIG.

  In this figure, four fixing portions 515 that sandwich the holder 506 from the vertical direction in the figure are shown. These four fixing portions 515 are for fixing the position of the holder 506 in the horizontal direction in the figure, and in order to fix the position of the holder 506 in the direction perpendicular to the figure, A fixing portion 515 (not shown) is provided. These fixing portions 515 include an arm 515a that expands and contracts in a direction along the eccentricity correction lens 20 (horizontal direction in this figure), and an arm storage portion 515b that stores a part of the arm 515a in accordance with the expansion and contraction of the arm 515a These fixing portions 515 can move in the vertical direction in the figure, and when the holder 506 is fixed, the arms 515a of the fixing portion 515 provided on the upper side of the holder 506 are arranged. The holder 506 is fixed by sandwiching the holder 506 from the up and down direction in the figure between the bent tip and the bent tip of the arm 515a of the fixing portion 515 provided on the lower side of the holder 506. . Further, since the position where the holder 506 in the horizontal direction is sandwiched is freely changed by the expansion and contraction of the arm 515a in the horizontal direction in the drawing, the eccentricity correction lens 20 is freely fixed at a position necessary for correcting the eccentricity.

  After such fixing, the application to the polymer actuator 500 is stopped and the polymer actuator 500 becomes unnecessary. However, since the polymer actuator 500 is elastic like rubber, the digital camera 1 When used, even when an impact is applied to the digital camera 1 from the outside, the attached polymer actuator 500 functions as a damper and has an effect of reducing damage to the eccentricity correction lens 20.

  The above is the description of the first embodiment of the present invention.

  As described above, the eccentricity correction mechanism of the digital camera 1 can correct the eccentricity by driving the eccentricity correction lens 20 with a simpler structure than a conventional mechanism using a small motor, and is relatively inexpensive. The cost of the eccentricity correction mechanism can be suppressed by using the polymer actuator.

  In the first embodiment, the imaging device that is the target of eccentricity correction is a digital camera. However, the present invention may also correct the eccentricity of a camera module provided in a mobile phone or the like. In this case, instead of providing the camera-side connector 510a for correcting eccentricity as shown in FIG. 2, a form in which the camera module has a USB terminal or the like is possible.

[Second Embodiment]
In the first embodiment, the eccentricity correcting lens 20 is connected to the polymer actuator 500 via the holder 506. However, by using a transparent and excellent dielectric elastomer, the holder 506 is not used. In addition, an embodiment in which the decentering correction lens and the polymer actuator are directly connected is also possible. In the following, such an embodiment will be described. In the second embodiment described below, unlike the first embodiment, the decentration correction lens and the polymer actuator are directly connected without a holder, and the decentering correction lens is replaced by a holder. A fixing portion for fixing both ends is provided. Except for these points, the appearance and configuration of the imaging apparatus and the mechanism for correcting the eccentricity are the same as the appearance and configuration of the imaging apparatus and the mechanism for correcting the eccentricity described in the first embodiment. Therefore, redundant description of the appearance and configuration of the imaging device, the configuration of the eccentric device, and the mechanism for correcting the eccentricity will be omitted, and the following description will focus on different points.

  FIG. 10 is a cross-sectional view showing a state in which the decentration correction lens and the polymer actuator are directly connected.

  The dielectric elastomer 501 ′ of this embodiment has an excellent light transmittance, and a part of the dielectric elastomer 501 ′ is in close contact with the surface of the decentering correction lens 20 as shown in the figure. Here, the dielectric elastomer 501 ′ in close contact with the surface of the eccentricity correction lens 20 to support the eccentricity correction lens 20 corresponds to an example of the optical film according to the present invention. With such a configuration, the eccentric correction lens 20 moves to a position where the eccentricity is corrected as the dielectric elastomer 501 'expands and contracts. Further, in the second embodiment, a fixing portion 515 ′ for fixing both ends of the eccentricity correcting lens is provided instead of the holder, and this fixing portion 515 ′ is eccentric by the same mechanism as that of the first embodiment. By fixing both ends of the correction lens 20, the decentration correction lens 20 is fixed at a position where the decentration is corrected. Except for these points, the mechanism for correcting eccentricity is the same as that of the first embodiment, and redundant description is omitted.

  In the second embodiment, both ends of the eccentricity correction lens 20 are fixed to fix the eccentricity correction lens 20 at a position where the eccentricity is corrected. However, as a form different from such a form, a dielectric is previously provided. The elastomer 501 ′ is mixed with a UV curing agent that is cured by irradiation with ultraviolet rays, the eccentricity correction lens 20 is moved to a position where the eccentricity is corrected, and then the UV curing agent is cured by irradiation with ultraviolet rays to decenter. A configuration in which the correction lens 20 is fixed to the position is also possible.

[Third Embodiment]
In the first embodiment and the second embodiment, the decentering correction lens 20 is a single lens, but an embodiment in which decentering is corrected using a combination lens (lens group) is also possible. Hereinafter, an embodiment in which such a combination lens is used as a decentration correction lens will be described. The third embodiment described below is different from the second embodiment in that the decentering correction lens is a combination lens, and the number of lenses increases and the weight increases. In addition to these points, the external appearance and configuration of the imaging apparatus, and the mechanism for correcting eccentricity are the external appearance and configuration of the imaging apparatus described in the second embodiment, and It is the same as the mechanism for correcting eccentricity. Accordingly, redundant description of the appearance and configuration of the imaging apparatus and the mechanism for correcting the eccentricity will be omitted, and the following description will focus on different points.

  FIG. 11 is a cross-sectional view showing a state where a plurality of decentering correction lenses and a polymer actuator are connected.

  As shown in this figure, the dielectric elastomer 501 'is in close contact with the surface of the lens 20 on the upper side in the figure with respect to the decentering correction combination lens composed of the two lenses 20, 20'. Further, a flange 506A is provided around the upper lens 20, and this flange 506A includes a guide 506B extending from the outer frame 507 toward the lens 20, and lower electrodes 502a and 502c of the polymer actuator 500. The structure sandwiched between the two lenses prevents the positions of the two lenses 20 and 20 'from shifting downward in the figure, and the number of lenses increases and the weight increases. The part that was made is reinforced. In the third embodiment, the position of the combination lens is fixed by a fixing unit having a mechanism similar to that of the fixing unit 515 ′ of the second embodiment, which fixes both ends of the combination lens. Here, the illustration is omitted.

[Fourth Embodiment]
In the first to third embodiments described above, the cross section perpendicular to the direction of the subject light of the outer frame 507 to which the polymer actuator is fixed has a square shape. In addition, an embodiment having a circular cross section is possible. Hereinafter, an embodiment in which the cross section of the outer frame is a circle will be described.

  FIG. 12 is a view showing a polymer actuator and an eccentricity correcting lens fixed to an outer frame having a circular cross section.

  In this fourth embodiment, as shown in this figure, as in the case of the square cross section shown in FIG. 3, there are provided four sets of electrodes each consisting of a set of an anode and a cathode. A voltage is applied to the sandwiched dielectric elastomer 501. The external appearance and configuration of the imaging apparatus and the mechanism for correcting the eccentricity other than the difference in the shape of the outer frame 507 ′ are the same as the external appearance and configuration of the imaging apparatus described in the first embodiment and the mechanism for correcting the eccentricity. is there. Therefore, redundant description of the appearance and configuration of the imaging apparatus and the mechanism for correcting the eccentricity is omitted.

[Fifth Embodiment]
In the first to fourth embodiments described above, the amount of voltage applied to the four sets of electrodes is adjusted for the drive control of the polymer actuator. However, as another method, for example, voltage application An embodiment adopting a system (so-called PWM control system) that controls driving of the optical element for decentration correction by adjusting the application time (time during which it is turned on) in two stages of on / off is also possible. In the following, such an embodiment will be described.

  FIG. 13 is a diagram illustrating a configuration for applying on / off two-stage voltages to four sets of electrodes of a polymer actuator.

  As shown in this figure, instead of the four voltage adjusting units 503a, 503b, 503c, and 503d shown in FIG. 4, four switches 503a ′, 503b ′, 503c ′, and 503d ′ are provided. However, by switching the wiring between the power supply 102 and the ground side shown in the figure, voltage application to each electrode is turned on and off, and the operation of this switch is controlled by the controller 505. In such switch control, the voltage itself for each electrode has only a binary value of zero voltage and the power supply voltage. However, the controller 505 switches the binary voltage value by the switch control to switch the period. A typical square wave voltage. The period of the rectangular wave voltage is sufficiently shorter than the response time of the dielectric elastomer 501 with respect to voltage application. Therefore, the rectangular wave voltage is smoothed by the response time, and is effectively smaller than the power supply voltage for the dielectric elastomer 501. The same effect as when a constant voltage is applied is produced. The magnitude of this effective voltage is determined according to the voltage application time (on time) of the rectangular wave voltage at this time, and the effective voltage applied to each electrode is controlled by the controller 505. The voltage value is controlled properly.

  In addition, in this 5th Embodiment, although the system which controls an effective voltage value by the voltage application time (time which is turned on) of the rectangular wave voltage in this way is adopted, in the present invention, in addition to this, A method in which effective voltage value control is performed by controlling the period of rectangular wave voltages having the same width and height is also possible.

  In the fifth embodiment, the voltage applied to the polymer actuator 500 is turned on / off by four switches. The present invention uses a circuit element such as a thyristor or a MOS type FES, for example, to apply a pulse voltage. The voltage applied to the polymer actuator 500 may be turned on / off through on / off of current passing through the circuit element.

  In the fifth embodiment, the voltage is received from the power supply 102 as described above. However, the present invention may use a high voltage supplied to the flash light emitting unit 12.

  Except for the point that the optical element for decentration correction is driven by controlling the voltage application time in two stages of voltage application on and off, the appearance and configuration of the imaging apparatus according to the fifth embodiment and the mechanism for correcting decentration are as follows. The appearance and configuration of the imaging apparatus described in the first embodiment and the mechanism for correcting eccentricity are the same. Therefore, redundant description of the appearance and configuration of the imaging apparatus and the mechanism for correcting the eccentricity is omitted.

[Sixth Embodiment]
In the embodiment described above, the voltage is applied according to the amount of eccentricity and the eccentricity is corrected. In addition to such a form, the voltage is released according to the amount of eccentricity and the eccentricity is corrected. A form in which the correction is performed is also possible. Below, the form which performs the open | release of the voltage according to the amount of eccentricity is demonstrated as 6th Embodiment.

  In the sixth embodiment, the appearance and configuration of the photographing apparatus are the same as the appearance and configuration of the photographing apparatus described in the first embodiment, and redundant description is omitted. In this sixth embodiment, voltage is applied to the polymer actuator before the eccentricity correction, and when the necessity of correcting the eccentricity is recognized, an appropriate electrode is selected according to the amount of eccentricity. The voltage for the electrode is released. The release of the voltage causes the dielectric elastomer sandwiched between the selected electrodes to shrink, and the shrinking force at this time causes the dielectric elastomer around the contracted dielectric elastomer to stretch. The movement of the dielectric elastomer drives the eccentricity correction lens to correct the eccentricity.

  The above is the description of the embodiment of the present invention.

1 is an external perspective view of a digital camera that is a first embodiment of an imaging apparatus included in an imaging system of the present invention. FIG. 2 is a diagram illustrating a schematic internal configuration of the digital camera 1 illustrated in FIG. 1 and a schematic internal configuration of an eccentricity correction apparatus connected to the digital camera 1. FIG. 3 is a diagram illustrating an eccentricity correction lens illustrated in FIG. 2 and a mechanism for driving the eccentricity correction lens. It is a figure showing the structure for applying a voltage to four sets of electrodes which the polymer actuator shown in FIG. 3 has. FIG. 4 is a cross-sectional view of the decentration correction lens and polymer actuator shown in FIG. 3. FIG. 7 is a diagram showing a structure of an outer frame shown in FIGS. 5 and 6 for fixing an end of a polymer actuator. It is a flowchart showing the flow of work when correction | amendment of eccentricity is performed. FIG. 6 is a cross-sectional view of an eccentricity correcting lens and a polymer actuator, showing a state when a voltage is applied to the left electrode in the state of FIG. 5. It is a figure showing the mechanism for fixing the position of the lens for eccentricity correction shown in FIG. It is sectional drawing showing a mode that the lens for eccentricity correction | amendment and the polymer actuator were connected directly. It is sectional drawing showing a mode that the several lens for eccentric correction and the polymer actuator were connected. It is a figure showing the polymer actuator and the lens for decentration correction | amendment fixed to the outer frame which has a circular cross section. It is a figure showing the structure for applying the voltage of two steps of ON / OFF to four sets of electrodes of a polymer actuator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Digital camera 10 Shooting lens 12 Flash light emission part 13 Finder objective window 14 Shutter button 20, 20 'Lens 30 Aperture 101 Switch group 110a ROM
102 Power supply 120 CPU
140 bus 40 CCD
131 A / D unit 133 White balance / γ processing unit 132 Clock generator 134 Buffer memory 138 YC / RGB conversion unit driver 160 Image display LCD
137 YC processing part 136 I / F
170 Memory card 500 Polymer actuator 501, 501 ′ Dielectric elastomer 502 a, 502 b, 502 c, 502 d Electrode 503 a, 503 b, 503 c, 503 d Voltage adjustment unit 503 a ′, 503 b ′, 503 c ′, 503 d ′ Switch 504 Operation unit 505 Controller 506 506 ′ holder 506A collar 506B guide 507, 507 ′ outer frame 507a first presser plate 507b second presser plate 507c screw 507d convex portion 510a camera side connector 510b device side connector 515, 515 ′ fixing portion 515a arm 515b arm housing portion 520 Eccentricity correction device

Claims (10)

An imaging device that forms subject light to generate an image signal representing the subject image, and is detachably attached to the imaging device, and controls the imaging device to correct a deviation in the imaging position of the subject light. In an imaging system comprising an imaging position correction unit that
A movable optical element that changes the direction of the transmitted subject light by transmitting the subject light and moving in a two-dimensional plane intersecting the direction of the subject light;
The movable optical element is connected to a support member that is disposed apart from the movable optical element and supports the movable optical element, and is stretched by applying a voltage. A polymer actuator comprising a plurality of electrodes that are arranged in contact with each other on the surface of the polymer film and that partially apply a voltage to the polymer film;
An imaging device including a connection portion to which the imaging position correction unit is detachably attached; and recognizing the amount of deviation of the imaging position of subject light, and applying a voltage according to the amount of deviation An imaging position correction unit including a shift correction unit that corrects a shift in the imaging position of subject light by moving the movable optical element in the two-dimensional plane;
An imaging system comprising:   The imaging system according to claim 1, wherein the movable optical element is a lens.   At least a part of a portion of the movable optical element excluding a portion bonded to the movable optical element, which is formed of a light-transmitting material bonded to a transmission surface through which subject light is transmitted, The imaging system according to claim 1, further comprising an optical film integrally connected to the polymer film. The imaging apparatus includes an image signal generation unit that generates an image signal in response to irradiation of subject light transmitted through the movable optical element;
The imaging system includes a shift amount calculation unit that calculates the shift amount of the imaging position of the subject light from the image signal;
The imaging system according to claim 1, wherein the shift correction unit recognizes the shift amount by acquiring the shift amount calculated by the shift amount calculation unit.   The imaging system according to claim 1, wherein the shift correction unit applies a voltage having a magnitude corresponding to the shift amount.   The imaging system according to claim 1, wherein the shift correction unit applies a pulse voltage having a pulse width corresponding to the shift amount.   The image pickup apparatus includes a position fixing unit that fixes the movable optical element at a position of the movable optical element when the shift of the imaging position is corrected by the shift correction unit. The imaging system described.   The imaging system according to claim 1, wherein, when a varying voltage is applied, the polymer film expands and contracts in accordance with an average voltage of the varying voltage. The polymer film is stretched upon release of an applied voltage,
The imaging system according to claim 1, wherein the shift correction unit is configured to control the voltage applied to the plurality of electrodes by applying and releasing the voltage instead of applying the voltage to the plurality of electrodes. In an imaging position correction method for correcting a shift in the imaging position of subject light in an imaging device that forms subject light and generates an image signal representing the subject image,
A shift amount recognition process for recognizing a shift amount of the imaging position of the subject light;
A movable optical element that transmits the subject light and moves in a two-dimensional plane intersecting the direction of the subject light to change the direction of the transmitted subject light, and the movable optical element that is disposed apart from the movable optical element A polymer film that is connected to a support member that supports an element and expands and contracts when a voltage is applied, and the polymer film that is divided and disposed on the surface of the polymer film in contact with the polymer film For a polymer actuator comprising a plurality of electrodes for partially applying a voltage to the plurality of electrodes, a voltage corresponding to the amount of deviation recognized by the deviation amount recognition process is applied to the plurality of electrodes, A shift correction process for correcting a shift in the imaging position of the subject light by moving the movable optical element in the two-dimensional plane;
An imaging position correction method comprising: a position fixing step of fixing the movable optical element at a position of the movable optical element when a deviation in imaging position is corrected by the deviation correction process.

Images