JP2010136189A - Vibrating device of optical member and digital camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To abolish an electrode dedicated to vibration detection. <P>SOLUTION: A low-pass filter 212 is vibrated by driving a diaphragm 261 in order to shake off a foreign substance deposited on a front-side surface of the low-pass filter 212, a vibrating state of the low-pass filter 212 is detected by a diaphragm 262, and a vibrating state of the diaphragm 261 is controlled on the basis of the detected vibrating state. The low-pass filter 212 is then vibrated by driving the diaphragm 262 in order to sweep away a foreign substance deposited on the front-side surface of the low-pass filter 212, a vibrating state of the low-pass filter 212 is detected by the diaphragm 261, and a vibrating state of the diaphragm 262 is controlled on the basis of the detected vibrating state. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vibration device for an optical member that removes foreign matter adhering to the optical member by vibrating the optical member, and a digital camera including the vibration device for the optical member.

  There is known a digital camera that removes a foreign substance attached to an optical member by vibrating the optical member. In this digital camera, it is possible to detect whether or not the dustproof filter vibrates correctly by detecting the vibration state of the optical member (dustproof filter) to be vibrated (see Patent Document 1).

JP 2004-29145 A

  However, the camera described in Patent Document 1 requires an electrode only for vibration detection.

(1) The vibration device for an optical member according to the invention of claim 1 can vibrate the optical member disposed on the front surface of the image sensor on the subject side, and can detect the vibration state of the optical member. The first vibrating member is driven to vibrate at least the first and second vibrating members and the foreign matter adhering to the optical member, the optical member is vibrated, and the vibration state of the optical member is changed by the second vibrating member. Detecting, controlling the vibration state of the first vibration member based on the detected vibration state, driving the second vibration member to wipe off the foreign matter adhering to the optical member, and vibrating the optical member; And a control means for detecting the vibration state of the optical member by the vibration member and controlling the vibration state of the second vibration member based on the detected vibration state.
(2) According to a second aspect of the present invention, in the vibration device for an optical member according to the first aspect, the first and second vibration members are traveling directions of vibration waves of the optical member that is vibrated by the first vibration member. And the traveling direction of the vibration wave of the optical member that is vibrated by the second vibrating member is arranged so as to be substantially parallel.
(3) According to a third aspect of the present invention, in the vibration device for an optical member according to the first aspect, the first and second vibration members are traveling directions of vibration waves of the optical member that is vibrated by the first vibration member. And the traveling direction of the vibration wave of the optical member vibrated by the second vibrating member is arranged so as to be substantially orthogonal.
(4) The invention of claim 4 is the optical member vibration device according to any one of claims 1 to 3, wherein the control means drives the first vibration member at the first excitation frequency, Next, the second vibration member is driven at the first vibration frequency, and then the first vibration member is driven at a second vibration frequency different from the first vibration frequency, and then the second vibration member is driven. The vibration state of the first and second vibrating members is controlled so as to drive the second vibrating member with a frequency.
(5) A digital camera according to a fifth aspect of the invention includes the optical member vibration device according to any one of the first to fourth aspects, and an imaging element that captures a subject image.

  According to the present invention, an electrode only for vibration detection becomes unnecessary.

  A first embodiment of a vibration device for an optical member and a digital camera according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a digital still camera provided with a vibration device for an optical member according to the present embodiment as viewed from the side. For convenience of explanation, front and rear, left and right, and up and down directions are defined as shown in each drawing. The horizontal direction is defined so as to coincide with the horizontal direction when the digital still camera is viewed from the front. This digital still camera CA is an interchangeable lens single-lens reflex type, and an interchangeable lens LB having a photographing lens L is attached to the camera body CB via a lens mount 21. The photographic light flux that has passed through the photographic lens L is guided into the camera body CB through the opening 21a of the lens mount 21, reflected by the mirror 22 and imaged on the finder screen 23, and passes through the pentaprism 24 and the eyepiece 25. Observed through.

  When the release operation is performed, the mirror 22 is flipped up and retracted from the photographing optical path, and then the focal plane shutter 100 that is a shutter device is driven, and the transmitted light flux of the photographing lens L is a CCD provided in the imaging unit 200. Or the like is incident on the image sensor 250. The photoelectric conversion output of the image sensor 250 is subjected to various processes by an image processing unit described later, and digital image data is generated. Note that an imaging element (for example, CMOS) other than a CCD may be used for the imaging element 250.

  FIG. 2 is a block diagram illustrating the configuration of the digital still camera CA. The arithmetic circuit 101 is configured by a microcomputer or the like. The arithmetic circuit 101 receives a signal output from each unit described later, performs a predetermined calculation, and outputs a control signal based on the calculation result to each unit. The arithmetic circuit 101 and each unit described later are connected to each other.

  The image sensor 250 captures an image of subject light that has passed through the photographing lens L, and outputs an image signal to the image processing unit 123. The image processing unit 123 is configured by an A / D conversion circuit, an ASIC, and the like. The image processing unit 123 converts an analog imaging signal into a digital signal and performs image processing such as white balance processing on the digitally converted image data. The image processing unit 123 performs a compression process for compressing the image data after image processing in a predetermined format, a decompression process for decompressing the compressed image data, and the like.

  The release switch 141 outputs a release operation signal to the arithmetic circuit 101 in conjunction with a release button (not shown). The release operation signal includes a half-press operation signal corresponding to a half-press operation of the release button and a full-press operation signal corresponding to a full-press operation pressed deeper than the half-press operation. The operation switch 143 is a switch group that is provided in the camera body CB and outputs an operation signal to the arithmetic circuit 101 when each operation button (not shown) is operated.

  The diaphragm control device 151 is a device that drives diaphragms 261 and 262 described later based on a signal output from the arithmetic circuit 101. Further, as will be described later, the diaphragm control device 151 receives electrical signals obtained from the diaphragms 261 and 262.

  The display control unit 161 is a control unit that performs display control of the display device 7a provided on the back surface of the camera body CB, for example, based on a signal output from the arithmetic circuit 101. Based on the signal output from the arithmetic circuit 101, the lens drive control unit 163 drives the lens group (photographing lens L) of the interchangeable lens LB so as to perform a focusing operation and a focal length changing operation. The sequence motor drive unit 164 drives the sequence motor 164a based on the signal output from the arithmetic circuit 101. The sequence motor 164a is a motor for performing the rotation of the mirror 22, the charging operation of the focal plane shutter 100, and the like.

  The storage medium mounting unit 165 detachably holds a storage medium (not shown), reads and erases data recorded on the mounted storage medium, and writes data to the storage medium. Image data after image processing is recorded on the storage medium. Note that a magnet for starting the operation of the focal plane shutter 100, a photometric sensor for exposure control, and the like are not directly related to the present invention, and thus description thereof is omitted.

-Imaging unit 200-
3 is a perspective view of the imaging unit 200, FIG. 4 is an exploded view of the imaging unit 200, FIG. 5 is a cross-sectional view of the imaging unit 200 viewed from the left side, and FIG. It is sectional drawing when seeing from the lower part. As shown in FIGS. 3 and 4, the imaging unit 200 includes a holder 201, an imaging substrate 251, an imaging element 250, a mask 202, a low-pass filter 211, a fixing member 203, a seal member 204, and a low-pass filter 212. And a low-pass filter pressing spring 205 and a fixing member pressing spring 206. The holder 201 is a member to which the imaging element 250, the imaging substrate 251, the fixing member 203, and the like are attached. The imaging substrate 251 is a substrate to which the imaging element 250 is connected, and is connected to the image processing unit 123 described above.

  As described above, the image sensor 250 is a solid-state image sensor such as a CCD. The image sensor 250 is bonded and fixed to the convex portion of the holder 201 indicated by reference numeral 201a in FIG. 4 while being electrically connected to the image pickup substrate 251. The mask 202 is a frame-like member made of an elastic body such as rubber, and is disposed in front of the image sensor 250. The mask 202 blocks object light from entering the area other than the imaging area of the image sensor 250, prevents foreign objects from entering a space between the low-pass filter 211 and the image sensor 250, which will be described later, and low-passes the image sensor 250. The position of the filter 211 is determined.

  The low-pass filter 211 is an optical member for preventing moire and the like. The low-pass filter 211 is positioned and fixed with respect to the image sensor 250 by being pressed against the mask 202 by a biasing force of a fixing member pressing spring 206 via a fixing member 203 described later. An infrared cut filter that cuts infrared light may be provided on the front or rear surface of the low-pass filter 211.

  The fixing member 203 is a member to which a low-pass filter 212, a seal member 204, and a low-pass filter holding spring 205, which will be described later, are attached and that presses the low-pass filter 211 and the mask 202 toward the holder 201. The seal member 204 is a member that is sandwiched between the fixing member 203 and the low-pass filter 212 and prevents foreign matter from entering the space behind the low-pass filter 212. The low-pass filter 212 is an optical member for preventing moire and the like, similar to the low-pass filter 211 described above. Diaphragms 261 and 262 described later are bonded and fixed near the left and right ends of the front surface of the low-pass filter 212.

  The low-pass filter holding spring 205 is a substantially rectangular frame-shaped member for urging and fixing the low-pass filter 212 toward the fixing member 203 and extends inward in the left-right direction as shown in FIG. It has an existing arm 205a. When the low-pass filter holding spring 205 is fixed to the fixing member 203 with a screw 291 or the like, the arm portion 205 a comes into contact with the front surface of the low-pass filter 212 and bends. The low-pass filter holding spring 205 urges the low-pass filter 212 toward the fixed member 203 by the urging force generated by the bending of the arm portion 205a. The arm portion 205 a abuts the front surface of the low-pass filter 212 on the outer side in the left-right direction with respect to the diaphragms 261 and 262 to urge the low-pass filter 212. Thereby, the low-pass filter holding spring 205 does not inhibit the vibration of the low-pass filter 212 by the diaphragms 261 and 262. The low-pass filter holding spring 205 is positioned by fitting the boss 203b of the fixing member 203 into the hole 205b provided in the low-pass filter holding spring 205 (FIG. 3). Also. The position of the low-pass filter 212 in the vertical and horizontal directions with respect to the fixed member 203 is determined by the boss 203 a of the fixed member 203.

  The fixing member pressing spring 206 is a spring member for fixing the fixing member 203 to the holder 201. When the fixing member pressing spring 206 is attached to the holder 201 with a screw 292, the fixing member pressing spring 206 is fixed while urging the fixing member 203 to which the low-pass filter 212, the seal member 204, and the low-pass filter pressing spring 205 are attached toward the holder 201. The member 203 is fixed to the holder 201 (FIG. 3).

  When the fixing member pressing spring 206 is attached to the holder 201 by the screw 292, the fixing member 203 biased by the fixing member pressing spring 206 presses the low-pass filter 211 and the mask 202 toward the holder 201 as described above. And fix. In this manner, the imaging substrate 251, the imaging element 250, the mask 202, the low-pass filter 211, the fixing member 203, the seal member 204, and the low-pass filter 212 are fixed to the holder 201. The holder 201 to which these members are attached, that is, the imaging unit 200 is attached and fixed to the camera body CB.

  5 and 6, the front side surface of the image sensor 250 to the rear surface of the low-pass filter 211 and the front side surface of the low-pass filter 211 to the rear side surface of the low-pass filter 212 are sealed as shown in FIGS. A space is formed. Therefore, no foreign matter enters the space from the outside. However, since the front surface of the low-pass filter 212 is exposed to the space in the camera body CB, foreign matter may adhere. Therefore, in the digital still camera CA according to the present embodiment, the low-pass filter 212 is vibrated by vibrating the diaphragms 261 and 262 so that the foreign matter attached to the front surface of the low-pass filter 212 is removed.

  FIG. 7 is a perspective view showing the low-pass filter 212 and the diaphragms 261 and 262. The diaphragms 261 and 262 are piezoelectric elements and extend along the side (short side) extending in the vertical direction of the low-pass filter 212 in the vicinity of the left and right ends of the front surface of the low-pass filter 212. The diaphragms 261 and 262 are bonded and fixed to the front surface of the low-pass filter 212 as described above. The diaphragms 261 and 262 are electrically connected to the diaphragm control device 151 by flexible flexible printed circuit boards (hereinafter referred to as FPC) 263 and 264, respectively. The diaphragms 261 and 262 vibrate when driven by a drive signal having a predetermined frequency output from the diaphragm controller 151. When this vibration is transmitted to the low-pass filter 212, the low-pass filter 212 itself vibrates and removes foreign matter adhering to the front surface.

  As described above, since the diaphragms 261 and 262 are piezoelectric elements, a voltage is generated when an external force is applied. The diaphragm controller 151 can detect the voltage generated by the diaphragms 261 and 262, and the arithmetic circuit 101 can detect the vibration state of the low-pass filter 212 from the voltage of the diaphragms 261 and 262 detected by the diaphragm controller 151. . In the digital still camera CA according to the present embodiment, any one of the diaphragms 261 and 262 is driven to remove foreign matter adhering to the front surface of the low-pass filter 212, and based on the voltage generated on either one. Thus, the vibration state of the low-pass filter 212 is detected. Then, the vibration state of the driving diaphragm is feedback controlled so that the detected vibration state of the low-pass filter 212 becomes a predetermined vibration state. In addition, when the detected vibration state of the low-pass filter 212 does not become a predetermined vibration state in spite of the feedback control as described above, the diaphragms 261 and 262 are fixed to the low-pass filter 212 (adhesion state). It is determined that there is some problem, such as not good, and the user is notified of this.

  For example, when the diaphragms 261 and 262 are not fixed to the low-pass filter 212 (adhesion state), sufficient vibration cannot be transmitted to the low-pass filter 212 even if the diaphragm is vibrated. I can't vibrate. Further, when detecting the vibration of the low-pass filter 212, the vibration of the low-pass filter 212 is difficult to be transmitted to the diaphragm, so that even if the voltage generated in the diaphragm is reduced and the low-pass filter 212 is sufficiently vibrated. Apparently, the low-pass filter 212 is observed not to vibrate sufficiently.

  For example, when the connection state between the diaphragms 261 and 262 and the FPCs 263 and 264 is not good, the drive signal is not sufficiently transmitted to the diaphragm even if a drive signal is given from the diaphragm controller 151 to the diaphragm. Therefore, the low-pass filter 212 cannot be sufficiently vibrated. Further, when detecting the vibration of the low-pass filter 212, the voltage (electric signal) generated in the diaphragm due to the vibration of the low-pass filter 212 cannot be sufficiently transmitted to the diaphragm controller 151, and the low-pass filter 212 is apparently sufficient. It is observed that it does not vibrate.

  Therefore, the arithmetic circuit 101 specifically vibrates the low-pass filter 212 so as to wipe off foreign matter adhering to the front surface of the low-pass filter 212 as follows, and also vibrates the low-pass filter 212 by the diaphragms 261 and 262. The state is judged as good or bad. When a power switch (not shown) of the digital still camera CA is turned on, and an operation button (not shown) is operated in a state where the power of the digital still camera CA is turned on, the arithmetic circuit 101 Either one of the diaphragms 261 and 262 (for example, the diaphragm 261) is driven to vibrate at a predetermined first frequency, and a voltage generated at the other (for example, the diaphragm 262) is detected. The diaphragm control device 151 is controlled.

  As a result, the diaphragm control device 151 outputs a drive signal to the diaphragm 261 so that the diaphragm 261 vibrates at the first frequency. The diaphragm control device 151 detects the voltage generated in the diaphragm 262 and outputs information indicating the detection result (for example, information such as a voltage value or a vibration frequency value) to the arithmetic circuit 101. The arithmetic circuit 101 outputs a drive signal output from the diaphragm control device 151 to the diaphragm 261 so that the vibration state of the low-pass filter 212 becomes a predetermined vibration state based on the information output from the diaphragm control device 151. The feedback voltage is controlled. Here, the predetermined vibration state of the low-pass filter 212 is, for example, that the amplitude of the vibration of the low-pass filter 212 reaches a predetermined amplitude sufficient for the removal of attached foreign matter, and the voltage generated in the diaphragm 262 is a predetermined value. This is a case where it is determined that the voltage has reached (specified voltage value hereinafter).

  If the voltage generated at the diaphragm 262 does not reach the specified voltage value, the arithmetic circuit 101 performs feedback control so as to increase the voltage of the drive signal output from the diaphragm controller 151 to the diaphragm 261. The arithmetic circuit 101 also performs feedback control so as to decrease the voltage of the drive signal output from the diaphragm control device 151 to the diaphragm 261 if the voltage generated at the diaphragm 262 exceeds the specified voltage value to some extent. To do. That is, the arithmetic circuit 101 feedback-controls the voltage of the drive signal output from the diaphragm control device 151 to the diaphragm 261 so that the voltage generated at the diaphragm 262 maintains a value near the specified voltage value.

  Furthermore, the arithmetic circuit 101 determines whether the vibration state of the low-pass filter 212 is good or not based on the information output from the diaphragm control device 151. For example, when the arithmetic circuit 101 determines that the voltage generated in the diaphragm 262 has reached a predetermined value (for example, a specified voltage value) based on the information output from the diaphragm controller 151, It is determined that the vibration state of the low-pass filter 212 is good. Further, the arithmetic circuit 101 increases the voltage of the drive signal output to the diaphragm 261 to a predetermined voltage value (hereinafter referred to as drive voltage application upper limit value) based on the information output from the diaphragm control device 151. Even in the case where it is determined, if it is determined that the voltage generated in the diaphragm 262 has not reached the specified voltage value, it is determined that the vibration state of the low-pass filter 212 is defective.

  When it is determined that the vibration state of the low-pass filter 212 is defective, the arithmetic circuit 101 determines that the vibration function of the diaphragms 261 and 262 is defective. In other words, in this case, the arithmetic operation circuit 101 determines that there is a possibility that the vibration force sufficient to wipe off the foreign matter attached to the front surface of the low-pass filter 212 may not be applied. The arithmetic circuit 101 controls the display control unit 161 to display a message indicating that the vibration state of the low-pass filter 212 is defective on the display device 7a for a certain period of time and notify the user. As a result, as shown in FIG. 8A, a message indicating that the vibration state of the low-pass filter 212 is defective is displayed on the display device 7a for a certain period of time. Thereby, the user can recognize that the vibration state of the low-pass filter 212 is not good. Thereafter, the arithmetic circuit 101 controls each unit to cancel the dust drop mode and shift to the photographing mode (photographing standby state) without vibrating the diaphragms 261 and 262.

  When it is determined that the vibration state of the low-pass filter 212 is good, the arithmetic operation circuit 101 displays a message indicating that the dust removal operation is being performed while the diaphragm control device 151 vibrates the diaphragm 261. The display control unit 161 is controlled to display on the device 7a. As a result, as shown in FIG. 8B, the display device 7a displays a message indicating that the dust removal operation is being performed. When the diaphragm 261 is driven for a predetermined time, the diaphragm controller 151 outputs a driving end signal (dust removal end signal) of the diaphragm 216 to the arithmetic circuit 101. When the arithmetic operation circuit 101 receives the dust dropping end signal output from the diaphragm control device 151, the arithmetic circuit 101 reverses the other one of the diaphragms 261 and 262 (for example, the diaphragm 262) to the first frequency. The diaphragm control device 151 is controlled so as to detect the voltage generated at either one (for example, the diaphragm 261).

  As a result, the diaphragm control device 151 outputs a drive signal to the diaphragm 262 so that the diaphragm 262 vibrates at the first frequency. Further, the diaphragm control device 151 detects a voltage generated in the diaphragm 261 and outputs information representing the detection result to the arithmetic circuit 101. The arithmetic circuit 101 outputs a drive signal output from the diaphragm control device 151 to the diaphragm 262 so that the vibration state of the low-pass filter 212 becomes a predetermined vibration state based on the information output from the diaphragm control device 151. The feedback voltage is controlled.

  If the voltage generated at the diaphragm 261 does not reach the specified voltage value, the arithmetic circuit 101 performs feedback control so as to increase the voltage of the drive signal output from the diaphragm controller 151 to the diaphragm 262. Further, the arithmetic circuit 101 performs feedback control so as to decrease the voltage of the drive signal output from the diaphragm control device 151 to the diaphragm 262 if the voltage generated at the diaphragm 261 exceeds the specified voltage value to some extent. To do. That is, the arithmetic circuit 101 feedback-controls the voltage of the drive signal output from the diaphragm control device 151 to the diaphragm 262 so that the voltage generated at the diaphragm 261 maintains a value near the specified voltage value.

  Furthermore, the arithmetic circuit 101 determines whether the vibration state of the low-pass filter 212 is good or not based on the information output from the diaphragm control device 151. For example, when the arithmetic circuit 101 determines that the voltage generated in the diaphragm 261 has reached the specified voltage value based on the information output from the diaphragm controller 151, the vibration state of the low-pass filter 212 is determined. Is determined to be good. In addition, the arithmetic circuit 101 determines whether the driving signal voltage output to the diaphragm 261 is increased to the driving voltage application upper limit value based on the information output from the diaphragm control device 151. When it is determined that the voltage generated at 261 has not reached the specified voltage value, it is determined that the vibration state of the low-pass filter 212 is defective.

If there is no problem on both the diaphragm 261 side and the diaphragm 262 side, the generation and transmission of the electrical signals or vibrations listed in the following (a) to (g) are not hindered. Even if the voltage of the output drive signal is not increased to the drive voltage application upper limit value, the voltage detected by the diaphragm control device 151 reaches the specified voltage value. In addition, if any one of the vibration plate 261 side and the vibration plate 262 side has a defect, generation or transmission of an electric signal or vibration is hindered by any of the following (a) to (g). Even if the voltage of the drive signal output to 261, 262 is increased to the drive voltage application upper limit value, the voltage detected by the diaphragm control device 151 does not reach the specified voltage value.
(A) Transmission of drive signal from diaphragm controller 151 to diaphragm (b) Generation of vibration in diaphragm by drive signal (c) Transmission of vibration of diaphragm to low-pass filter 212 (d) Low-pass filter 212 itself (E) Transmission of vibration of low-pass filter 212 to diaphragm (f) Voltage generation in vibrating diaphragm (g) Transmission of voltage (electric signal) generated in diaphragm to control device 151

  If it is determined that the vibration state of the low-pass filter 212 is defective, the arithmetic circuit 101 determines that the vibration function of the diaphragms 261 and 262 is defective, and the low-pass filter is the same as described above. The display control unit 161 is controlled so that a message indicating that the vibration state 212 is defective is displayed on the display device 7a for a predetermined time to notify the user. As a result, as shown in FIG. 8A, a message indicating that the vibration state of the low-pass filter 212 is defective is displayed on the display device 7a for a certain period of time. Thereafter, the arithmetic circuit 101 controls each unit to cancel the dust drop mode and shift to the photographing mode (photographing standby state) without vibrating the diaphragms 261 and 262.

  When it is determined that the vibration state of the low-pass filter 212 is good, the arithmetic circuit 101 displays a message indicating that the dust removal operation is being performed while the diaphragm control device 151 vibrates the diaphragm 262. The display control unit 162 is controlled to display on the device 7a. As a result, as shown in FIG. 8B, the display device 7a displays a message indicating that the dust removal operation is being performed. When the diaphragm 262 is driven for a predetermined time, the diaphragm controller 151 outputs a dust dropping end signal to the arithmetic circuit 101. When the arithmetic operation circuit 101 receives the dust dropping end signal output from the diaphragm control device 151, the arithmetic circuit 101 sets the excitation frequency to the first frequency as in the case where each of the diaphragms 261 and 262 is driven at the first frequency described above. It is driven to vibrate at a predetermined second frequency different from the first frequency. The same applies to feedback control of drive signals output from the diaphragm control device 151 to the diaphragms 261 and 262 and determination of pass / fail of the vibration state of the low-pass filter 212. Thereafter, similarly, the arithmetic circuit 101 drives the excitation frequency to vibrate at a predetermined third frequency different from the first and second frequencies. Further, similarly, the arithmetic circuit 101 drives the excitation frequency to vibrate at a predetermined fourth frequency different from the first to third frequencies.

  When the diaphragm control device 151 drives the diaphragm 262 at the fourth frequency for a predetermined time, the diaphragm control device 151 outputs a dust drop end signal to the arithmetic circuit 101. When the arithmetic operation circuit 101 receives the dust removal end signal output from the diaphragm control device 151, the arithmetic operation circuit 101 controls each unit to cancel the dust removal mode and shift to the photographing mode (photographing standby state).

  In this way, by vibrating the low-pass filter 212 with different excitation frequencies, the low-pass filter 212 can be vibrated in various vibration modes (vibration modes), so that foreign matter adhering to the front surface of the low-pass filter 212 is effective. Can be paid off. The first to fourth frequencies described above are set so that the vibration in the low-pass filter 212 becomes a traveling wave. Therefore, the foreign matter can be efficiently removed regardless of the attachment position on the front surface of the low-pass filter 212. In the digital still camera CA of the present embodiment, the diaphragms 261 and 262 are arranged so that the traveling directions of the traveling waves generated in the low-pass filter 212 by the vibrations of the diaphragm 261 and the diaphragm 262 are substantially parallel to each other. It will be established.

--- Flow chart ---
9 and 10 are flowcharts showing the processing contents of a program that performs processing for vibrating the low-pass filter 212 described above. A program for performing this processing when a power switch (not shown) of the digital still camera CA is turned on and an operation button (not shown) is operated in a state where the power of the digital still camera CA is turned on and set to a dust removal mode. Is activated and executed by the arithmetic circuit 101. In step S1, 1 is substituted for variable N and the process proceeds to step S3. In step S3, the value of the variable N is read, the value of the Nth frequency is read from a memory (not shown), set as the excitation frequency of the diaphragms 261 and 262, and the process proceeds to step S11.

  In step S11, a control signal is output to the diaphragm controller 151 so as to drive the diaphragm 261 at the excitation frequency set in step S3 and to detect a voltage generated in the diaphragm 262, and the process proceeds to step S13. move on. In step S13, based on the information output from the diaphragm controller 151, the drive signal output from the diaphragm controller 151 to the diaphragm 261 so that the vibration state of the low-pass filter 212 becomes a predetermined vibration state. The voltage is feedback controlled and the process proceeds to step S14. In step S14, it is determined whether or not the voltage generated in the diaphragm 262 has reached a specified voltage value as a result of the feedback control in step S13.

  If an affirmative determination is made in step S14, that is, in step S14, the feedback control is performed in step S13, and the diaphragm 262 is not required to increase the voltage of the drive signal output to the diaphragm 261 to the drive voltage application upper limit value. If it is determined that the voltage generated at has reached the specified voltage value, the process proceeds to step S15. In step S15, a control signal is output to the diaphragm controller 151 so as to continue the vibration of the diaphragm 261 for a certain period of time at the currently set excitation frequency, and the process proceeds to step S16. In step S16, the display control unit 161 is controlled to display a message indicating that the dust removal operation is being performed on the display device 7a, and the process proceeds to step S19.

  In step S19, the process waits until the driving of the diaphragm 261 is completed, that is, until the dust dropping end signal output from the diaphragm control device 151 is received. When the dust dropping end signal is received, the process proceeds to step S21.

  In step S21, a control signal is output to the diaphragm control device 151 so as to drive the diaphragm 262 at the excitation frequency set in step S3 and to detect a voltage generated in the diaphragm 261, and the process proceeds to step S23. move on. In step S23, based on the information output from the diaphragm controller 151, the drive signal output from the diaphragm controller 151 to the diaphragm 262 so that the vibration state of the low-pass filter 212 becomes a predetermined vibration state. The voltage is feedback controlled and the process proceeds to step S24. In step S24, it is determined whether or not the voltage generated in the diaphragm 261 has reached a specified voltage value as a result of the feedback control in step S23.

  If the determination in step S24 is affirmative, that is, in step S24, the feedback control is performed in step S23, and the diaphragm 261 does not have to increase the voltage of the drive signal output to the diaphragm 262 to the drive voltage application upper limit value. When it is determined that the voltage generated in step S1 has reached the specified voltage value, the process proceeds to step S25 in FIG. In step S25, a control signal is output to the diaphragm controller 151 so as to continue the vibration of the diaphragm 262 for a certain period of time with the currently set excitation frequency, and the process proceeds to step S29.

  In step S29, the process waits until the driving of the diaphragm 262 is completed, that is, until the dust dropping end signal output from the diaphragm control device 151 is received. When the dust dropping end signal is received, the process proceeds to step S41.

  In step S41, it is determined whether or not the variable N is 4 or more. If an affirmative determination is made in step S41, the process proceeds to step S47, where the display control unit 161 is controlled so as to stop displaying the message displayed in step S16 or step S51 described later, and the dust removal mode is canceled and the shooting mode ( Control each part to shift to the shooting standby state) and return.

  If a negative determination is made in step S41, the process proceeds to step S43, 1 is added to the variable N, and the process returns to step S3 in FIG.

  If step S14 in FIG. 9 is negatively determined, that is, in step S14, feedback control is performed in step S13, and the voltage of the drive signal output to the diaphragm 261 is increased to the drive voltage application upper limit value. However, if it is determined that the voltage generated in the diaphragm 262 has not reached the specified voltage value, the process proceeds to step S51 in FIG. In step S51, the display control unit 161 is controlled so that a message indicating that the vibration state of the low-pass filter 212 is defective is displayed on the display device 7a for a predetermined time, and the process proceeds to step S53. In step S53, after waiting for a predetermined time corresponding to the display time of the message displayed on the display device 7a under the control of step S51, the process proceeds to step S47.

  If step S24 in FIG. 9 is negatively determined, that is, in step S24, feedback control is performed in step S23 to increase the voltage of the drive signal output to the diaphragm 262 to the drive voltage application upper limit value. However, if it is determined that the voltage generated in the diaphragm 261 has not reached the specified voltage value, the process proceeds to step S51 in FIG.

The digital still camera CA described above has the following operational effects.
(1) The vibration plate 261 is driven to vibrate the foreign matter adhering to the front surface of the low-pass filter 212, the low-pass filter 212 is vibrated, the vibration state of the low-pass filter 212 is detected by the vibration plate 262, and the detected vibration state Based on the above, the vibration state of the diaphragm 261 is controlled. Then, the vibration plate 262 is driven to vibrate the foreign matter adhering to the front surface of the low-pass filter 212, and the low-pass filter 212 is vibrated. The vibration state of the low-pass filter 212 is detected by the vibration plate 261, and the detected vibration state is obtained. Based on this, the vibration state of the diaphragm 262 is controlled. Therefore, since it can be detected whether or not the low-pass filter 212 is sufficiently vibrated when the foreign matter is removed, it is possible to detect whether the low-pass filter 212 has a vibration failure, that is, whether the diaphragms 261 and 262, the FPCs 263 and 264, or the like are defective. , Adhesive strength between the diaphragms 261 and 262 and the FPCs 263 and 264, adhesive strength between the diaphragms 261 and 262 and the low-pass filter 212, electrical conduction performance between the diaphragms 261 and 262 and the FPCs 263 and 264, and a fixed state of the low-pass filter 212 It is possible to determine whether or not there is a problem with the above. Thereby, the structure for judging whether there exists these malfunctions is easily realizable with a simple structure.

(2) One of the diaphragms 261 and 262 is driven to vibrate, and the vibration state of the low-pass filter 212 is detected based on the voltage generated on the other. Moreover, it comprised so that the diaphragm to vibrate and the diaphragm which detects a vibration could be replaced. This eliminates the need for a dedicated electrode for vibration detection, thereby reducing the cost.

(3) The imaging unit 200 is assembled and configured to detect the vibration state of the low-pass filter 212 when the imaging unit 200 is attached to the camera body CB. The vibration state of the driving diaphragm is feedback-controlled so that the detected vibration state of the low-pass filter 212 becomes a predetermined vibration state. Accordingly, even if the vibration state of the low-pass filter 212 changes due to the assembly as the imaging unit 200 or the attachment of the imaging unit 200 to the camera body CB, the vibration state of the low-pass filter 212 is changed. Can keep good. Even if the vibration state of the low-pass filter 212 changes due to secular change or the like, the vibration state of the low-pass filter 212 can be kept good.

(4) Since the low-pass filter 212 can be vibrated by the diaphragms 261 and 262 provided at different positions, it can be suppressed that the foreign matter removal effect differs depending on the foreign matter attachment position. .

(5) The diaphragms 261 and 262 are arranged so as to sandwich the region through which the imaging light flux is transmitted. As a result, the excitation source of the low-pass filter 212 and the vibration detection sensor are disposed across the area through which the imaging light beam is transmitted, so that the area through which the imaging light beam is transmitted is suitable for removing foreign matter. Whether or not the vibration state of the low-pass filter 212 is good can be optimized.

(6) The low-pass filter 212 is configured to vibrate at different excitation frequencies. As a result, the low-pass filter 212 can be vibrated in various vibration modes (vibration modes), so that foreign matter adhering to the front surface of the low-pass filter 212 can be effectively removed.

(7) When it is determined that the vibration state of the low-pass filter 212 is defective, a message indicating that the vibration state of the low-pass filter 212 is defective is displayed on the display device 7a for a predetermined time. Thereby, the user can recognize that the vibration state of the low-pass filter 212 is not good. Therefore, despite the fact that the dust removal mode is set and the foreign matter removal operation is performed, the foreign matter attached to the front surface of the low-pass filter 212 cannot actually be sufficiently removed, and the effect expected by the user. It is possible to avoid problems such as being unable to obtain

(8) When it is determined that the vibration state of the low-pass filter 212 is defective, the diaphragms 261 and 262 are not vibrated thereafter. Thereby, even if it is implemented due to a problem, it is possible to omit the driving of the diaphragms 261 and 262, which has a low effect of removing foreign matter, so that the power consumption of the digital still camera CA can be suppressed.

(9) The diaphragms 261 and 262 are vibrated by a drive signal having a predetermined frequency output from the diaphragm controller 151, and the voltage generated by the diaphragms 261 and 262 can be detected by the diaphragm controller 151. . As a result, the number of connection points between the diaphragms 261 and 262 and the FPCs 263 and 264 can be kept to a minimum, so that the probability of occurrence of a failure due to a connection failure at the connection point can be reduced and reliability can be improved.

(10) The imaging device 250, the low-pass filters 211 and 212, the diaphragms 261 and 262, and the like are attached to the holder 201, and the imaging unit 200 is configured integrally. Thereby, the imaging unit 200 itself can be easily assembled and the imaging unit 200 can be easily attached to the camera body CB.

---- Modified example ---
(1) In the above description, based on the information output from the diaphragm control device 151, the low-pass filter is determined depending on whether or not the voltage generated in the diaphragms 261 and 262 has reached a predetermined value (for example, a specified voltage value). Although it is configured to determine whether or not the vibration state 212 is good, the present invention is not limited to this. For example, based on the information output from the diaphragm control device 151, the frequency of the voltage generated in the diaphragms 261 and 262, that is, whether or not the vibration frequency of the low-pass filter 212 is a predetermined vibration frequency. You may comprise so that it may determine whether the vibration state of the low-pass filter 212 is favorable. Further, it may be configured to determine whether or not the vibration state of the low-pass filter 212 is good based on both the value of the voltage generated in the diaphragms 261 and 262 and the frequency.

(2) In the above description, the foreign matter is dispensed for a predetermined time, but the present invention is not limited to this. For example, the completion of the foreign substance payout may be detected as follows. For example, a light source is provided in the camera body CB. The arithmetic circuit 101 temporarily suspends the excitation of the low-pass filter 212 during the foreign object removal, and causes the imaging device 250 to capture an image while irradiating light from the front surface of the low-pass filter 212 with this light source. The arithmetic circuit 101 determines the presence or absence of foreign matter on the front surface of the low-pass filter 212 by performing image processing on an image obtained by imaging. Here, if it is determined that there is no foreign object, the arithmetic circuit 101 ends the foreign object removal, and if it is determined that there is a foreign object, the arithmetic circuit 101 restarts the excitation of the low-pass filter 212. After resuming the vibration of the low-pass filter 212, the arithmetic circuit 101 temporarily suspends the vibration again after a predetermined time, and performs the above-described determination processing for the presence of foreign matter. Hereinafter, the above process may be repeated as appropriate.

(3) In the above description, the diaphragms 261 and 262 are disposed so as to extend along the short side of the low-pass filter 212 in the vicinity of the left and right ends of the front surface of the low-pass filter 212. It is not limited. For example, as shown in FIG. 11, one diaphragm 265 extends so as to extend along the short side of the low-pass filter 212 near one of the left and right ends of the front surface of the low-pass filter 212 (near the right end in FIG. 11). And one diaphragm so as to extend along the side (long side) extending in the left-right direction of the low-pass filter 212 in the vicinity of one of the upper and lower ends of the front surface (near the lower end in FIG. 11). 266 may be provided. That is, the two diaphragms 265 and 266 may be arranged in an L shape. When the diaphragms 265 and 266 are arranged as described above, the traveling directions of the traveling waves generated by the low-pass filter 212 due to the vibrations by the diaphragm 265 and the diaphragm 266 are substantially orthogonal to each other. By making the traveling directions of the traveling waves substantially orthogonal to each other, the vibration mode can be increased compared to the case where the low-pass filter 212 is vibrated by the diaphragms 261 and 262 described above. The adhered foreign matter can be effectively removed.

(4) In the above description, the number of diaphragms 261 and 262 is two, but may be three or more. In this case, from the viewpoint of securing the photographing optical path, it is desirable to dispose the diaphragm in the vicinity of the left and right ends and the upper and lower ends of the front surface of the low-pass filter 212. In addition, from the viewpoint of easy vibration detection and productivity, it is desirable to dispose the diaphragm only on either the front surface or the rear surface of the low-pass filter 212. The front side surface 212 and the rear side surface 212 may be separately provided. For example, the diaphragms 261 and 262 may be disposed on the rear surface of the low-pass filter 212, and the diaphragm 266 may be disposed on the front surface of the low-pass filter 212 as shown in FIG.

(5) In the above description, the diaphragm 261 and the diaphragm 262 are sequentially vibrated at the first frequency, then the diaphragm 261 and the diaphragm 262 are sequentially vibrated at the second frequency, and then the third frequency. The diaphragm 261 and the diaphragm 262 are sequentially vibrated in the above, and then the diaphragm 261 and the diaphragm 262 are sequentially vibrated at the fourth frequency. However, the present invention is not limited to this. That is, the order of vibrations of the diaphragms 261 and 262 and the order of frequencies to be excited are not limited to the above description. For example, first, only the diaphragm 261 may be sequentially vibrated at the first to fourth frequencies, and then only the diaphragm 262 may be sequentially vibrated at the first to fourth frequencies. Further, the excitation frequency is not limited to four of the first to fourth frequencies, and may be an arbitrary number of 1 or more.

(6) In the above description, the digital still camera CA has been described as an example of the vibration device for an optical member and the digital camera according to the present invention, but the present invention is not limited to this. For example, it may be a camera having a video shooting function instead of a mere digital still camera, and is an electronic device that captures a subject image with an image sensor, and an optical member is disposed on the front surface of the image sensor, It may be a device that needs to wipe off foreign matter adhering to the surface.

(7) In the above description, the voltage of the drive signal output from the diaphragm control device 151 to the diaphragms 261 and 262 is feedback-controlled so that the vibration state of the low-pass filter 212 becomes a predetermined vibration state. However, the present invention is not limited to this. For example, the frequency of the drive signal output from the diaphragm control device 151 to the diaphragms 261 and 262 may be feedback-controlled so that the vibration state of the low-pass filter 212 becomes a predetermined vibration state. Further, both the voltage and the frequency of the drive signal output from the diaphragm control device 151 to the diaphragms 261 and 262 are feedback-controlled so that the vibration state of the low-pass filter 212 becomes a predetermined vibration state. Also good. As described above, the parameters for changing the vibration characteristics of the diaphragms 261 and 262 include not only the voltage of the drive signal but also the frequency.
(8) You may combine each embodiment and modification which were mentioned above, respectively.

  Note that the present invention is not limited to the embodiment described above, and the optical member disposed on the front surface of the image sensor on the subject side, the optical member can be vibrated, and the optical member is vibrated. At least the first and second vibrating members that can detect the state, and the first vibrating member is driven to vibrate the foreign member attached to the optical member, and the optical member is vibrated by the second vibrating member. The vibration state is detected, the vibration state of the first vibration member is controlled based on the detected vibration state, and the second vibration member is driven to vibrate the optical member in order to wipe off foreign matters attached to the optical member. And a control means for detecting the vibration state of the optical member by the first vibration member and controlling the vibration state of the second vibration member based on the detected vibration state. Vibration device Beauty, is intended to include digital cameras various structures including the resonator device of the optical member.

It is sectional drawing which looked at digital still camera CA from the side. It is a block diagram explaining the structure of digital still camera CA. 2 is a perspective view of an imaging unit 200. FIG. 2 is an exploded view of the imaging unit 200. FIG. It is sectional drawing when the imaging unit 200 is seen from the left side. It is sectional drawing when the imaging unit 200 is seen from the downward direction. 3 is a perspective view showing a low-pass filter 212 and diaphragms 261 and 262. FIG. It is a figure which shows the example of a display of the display apparatus 7a. It is a flowchart which shows the processing content of the program which performs the process for vibrating the low-pass filter. It is a flowchart which shows the processing content of the program which performs the process for vibrating the low-pass filter. It is a figure which shows a modification.

Explanation of symbols

7a Display device 101 Arithmetic circuit 151 Diaphragm control device 161 Display control unit 200 Imaging unit 211, 212 Low-pass filter 250 Imaging element 261, 262, 265, 266 Diaphragm 263, 264 Flexible printed circuit board (FPC)
CA digital still camera CB camera body

Claims (5)

An optical member disposed on the front surface of the image sensor on the subject side;
At least first and second vibrating members capable of vibrating the optical member and detecting a vibration state of the optical member;
The first vibration member is driven to vibrate foreign matter adhering to the optical member, the optical member is vibrated, the vibration state of the optical member is detected by the second vibration member, and the detected vibration The vibration state of the first vibration member is controlled based on the state, the second vibration member is driven to vibrate the optical member in order to wipe off the foreign matter adhering to the optical member, and the first vibration member is vibrated. A vibration device for an optical member, comprising: control means for detecting a vibration state of the optical member by a vibration member and controlling the vibration state of the second vibration member based on the detected vibration state. The vibration device for an optical member according to claim 1,
The first and second vibrating members include a traveling direction of a vibration wave of the optical member that is vibrated by the first vibrating member, and a traveling wave of the optical member that is vibrated by the second vibrating member. A vibration device for an optical member, wherein the vibration device is disposed so as to be substantially parallel to a direction. The vibration device for an optical member according to claim 1,
The first and second vibrating members include a traveling direction of a vibration wave of the optical member that is vibrated by the first vibrating member, and a traveling wave of the optical member that is vibrated by the second vibrating member. A vibration device for an optical member, wherein the vibration device is disposed so as to be substantially orthogonal to a direction. In the vibration device of the optical member according to any one of claims 1 to 3,
The control means drives the first vibrating member at a first excitation frequency, then drives the second vibrating member at the first excitation frequency, and then the first excitation frequency. Of the first and second vibrating members such that the first vibrating member is driven at a second exciting frequency different from the first vibrating member, and then the second vibrating member is driven at the second exciting frequency. A vibration device for an optical member, characterized by controlling a vibration state. The vibration device for an optical member according to any one of claims 1 to 4,
A digital camera comprising: an image sensor that captures a subject image.

Images