JP2006295844A - Optical apparatus with dust protection function - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical apparatus with a dust protection function for obtaining sure dust protection effect while surely reducing power consumption if an optical element for dust protection is included in an optical path of a photo-optical system. <P>SOLUTION: Presence/absence of dust stuck on an optical element 302 for dust protection disposed within an optical path of the photo-optical system 300 is discriminated by a dust presence/absence discriminating means 305 and based on a result of the discrimination, driving of a vibration means 303 is controlled, for example, only when presence of dust is discriminated, dust removing operation is performed by the vibration means 303. Thus, even when turning on a power source or mounting a photographic exchange lens, if dust is not stuck on the optical element 302 for dust protection, it is not necessary to perform the dust removing operation, so that power consumption is reduced and battery consumption can be suppressed. Furthermore, even when the dust removing operation is carried out, if dust is left, the dust removing operation can be repeated until dust is eliminated, thereby obtaining sure dust protection effect. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical device with a dustproof function capable of removing dust adhering to the inside of an electronic imaging device such as a digital camera system.

  2. Description of the Related Art In recent years, as an example of a technique related to a dustproof function of an optical device, a technique has been proposed in which dust attached to the glass is removed by vibrating a protective glass (dustproof glass) that protects an image sensor. As an example, according to Patent Document 1, a piezoelectric element is used as means for vibrating a glass plate. The piezoelectric element expands and contracts in response to an applied voltage to vibrate the glass plate at a predetermined cycle.

JP 2004-48665 A

  The thing of patent document 1 performs the dust-proof operation (dust removal operation | movement) which vibrates dust-proof glass every time the power supply of a camera is turned on, or at the time of the mounting | wearing of the interchangeable lens for imaging | photography. However, in this method, there is a case where the dustproof operation is performed even though no dust is attached to the dustproof glass, and there is a problem that the power consumption is wasted and battery consumption is accelerated. Further, even if dust adheres to the dust-proof glass, the dust-proof operation ends regardless of whether the dust has been removed, and the certainty of the dust-proof effect is lacking.

  The present invention has been made in view of the above, and has a dustproof function capable of obtaining a reliable dustproof effect while ensuring reduction of power consumption when a dustproof optical element is provided in the optical path of the photographing optical system. An object is to provide an optical device.

  In order to solve the above-described problems and achieve the object, an optical device with a dustproof function according to claim 1 is a photoelectric conversion element that receives an optical image of a subject formed by a photographing optical system and converts it into an electrical signal. And whether there are dust-proof optical elements disposed on the photographing optical path preceding the photoelectric conversion element, and dust or other foreign matters adhering to the optical element based on the output of the photoelectric conversion element. A dust presence / absence discriminating means for discriminating whether or not dust, a dust removing means for removing dust and other foreign matters adhering to the optical element, and a control for driving and controlling the dust removing means based on a discrimination result of the dust presence / absence discriminating means Means.

  According to a second aspect of the present invention, in the optical device with a dustproof function, in the above invention, the control unit causes the dust removal unit to perform a dust removal operation when the dust presence / absence determination unit determines that a foreign object is present. When it is determined by the dust presence / absence determining means that there is no foreign matter, drive control is performed so that the dust removing operation by the dust removing means is not performed.

  According to a third aspect of the present invention, in the optical device with a dustproof function according to the above invention, the control unit causes the dust removal unit to perform a dust removal operation when the dust presence / absence determination unit determines that there is a foreign object. If the dust presence / absence determining means determines again that there is a foreign object, the dust removing means performs the dust removal operation again, and if the dust presence / absence determining means determines that there is no foreign object, The drive control is performed so as not to perform the dust removing operation by the removing means.

  According to a fourth aspect of the present invention, there is provided an optical device with a dustproof function according to the above invention, wherein the control means changes an operation parameter in accordance with a dust detection result when the dust presence / absence determination means determines that a foreign object is present. The dust removing operation is performed by the dust removing means.

  The optical device with a dustproof function according to claim 5 is characterized in that, in the above invention, the detection result of the dust is information on the size of the dust, the number of dusts, and the position where the dust is present.

  The optical device with a dustproof function according to a sixth aspect is characterized in that, in the above invention, the operation parameter to be changed is an operation time or an operation count of the dust removing means.

  The optical device with a dustproof function according to a seventh aspect of the present invention is characterized in that, in the above invention, the dust removing means is a vibration means for vibrating the optical element at a predetermined frequency.

  An optical device with a dustproof function according to an eighth aspect of the present invention is the above invention, wherein the dust removing unit is a vibrating unit that vibrates the optical element at a predetermined frequency, and the operating parameter to be changed is that of the vibrating unit. It is an excitation time, an excitation frequency, or an applied voltage for driving.

  The optical device with a dustproof function according to claim 9 is the above invention, wherein the dust removing means is a vibrating means for vibrating the optical element at a predetermined frequency, and the operating parameter to be changed is the vibration of the vibrating means. It is a vibration mode.

  According to a tenth aspect of the present invention, in the optical device with a dustproof function according to the above invention, the dust presence / absence determining means determines the presence / absence of a foreign substance by comparing the luminance of pixel data output from the photoelectric conversion element. Features.

  The optical device with a dustproof function according to claim 11 is the above invention, wherein the pixel data is pixel data output from the photoelectric conversion element when receiving an optical image of a subject having a substantially uniform luminance distribution. Features.

  The optical device with a dustproof function according to a twelfth aspect of the present invention is the above invention, wherein the dust presence / absence discriminating means has a difference in average luminance of a predetermined number of pixels in the pixel data output from the photoelectric conversion element is a predetermined value or more In this case, it is characterized in that it is determined that there is a foreign object.

  The optical device with a dustproof function according to a thirteenth aspect is the above invention, wherein the dust presence / absence discriminating means has a predetermined pixel region and a peripheral region located around the pixel region for the pixel data output from the photoelectric conversion element. When the difference in luminance with respect to a predetermined value is greater than or equal to a predetermined value, it is determined that a foreign object is present.

  According to the optical device with a dustproof function according to the present invention, it is determined whether there is dust attached to the dustproof optical element disposed in the optical path of the photographing optical system, and dust removal is performed based on the determination result. Since the dust removal operation by the dust removal means is performed only when it is determined that dust is present, for example, even when the power is turned on or when an imaging interchangeable lens is attached, the dust-proof optical Since no dust removal operation is required if no dust is attached to the element, power consumption can be reduced, battery consumption can be reduced, and even if dust removal operation is performed, dust can remain. The dust removal operation can be repeated until it is exhausted, and there is an effect that a reliable dustproof effect can be obtained.

  Hereinafter, a digital camera system having a photoelectric conversion element as an optical device with a dustproof function of the present invention will be described in detail with reference to the accompanying drawings based on a plurality of embodiments.

(Embodiment 1)
FIG. 1 is a conceptual schematic block mainly showing a control system corresponding to a configuration example of a main part of a digital camera system as an optical apparatus with a dustproof function according to the first embodiment. This optical device with a dustproof function includes a photoelectric conversion element 301 that receives an optical image of a subject formed by a photographing optical system 300 mainly including a photographing lens and converts it into an electrical signal. Furthermore, the optical device with a dustproof function of the first embodiment is a dustproof optical element 302 disposed on the photographing optical path preceding the photoelectric conversion element 301, and dust removing means for vibrating the optical element 302. The vibration means 303 is provided. The vibration means 303 includes a piezoelectric element using, for example, an electromechanical conversion element such as piezoelectric ceramics, and a dust-proof glass driving circuit that vibrates the optical element 302 by driving the piezoelectric element at a predetermined driving frequency. However, any means capable of appropriately vibrating the optical element 302 may be used. Furthermore, the dust removing means is not limited to the vibration by the vibration means 303. For example, compressed air from an injection nozzle is blown by an air blower toward the surface of the optical element 302 for dust prevention, or a fan or the like is blown. A method of blowing air by means to blow away dust adhering to the surface of the dust-proof optical element 302, a method of moving the dust removing roller member along the surface of the dust-proof optical element 302, A method of removing dust attached to the surface of the dust-proof optical element 302 with a wiper mechanism may be used. Further, the optical device with a dustproof function of the first embodiment is provided with a control means 304 for controlling the operation of the dustproof glass driving circuit in the vibration means 303.

  The optical device with a dustproof function of the first embodiment also has a dust presence / absence discriminating unit 305 that discriminates whether or not dust attached on the optical element 302 or other foreign matter is present based on the output of the photoelectric conversion element 301. It has. The control unit 304 drives and controls the vibration unit 303 based on the determination result of the dust presence / absence determination unit 305. Specifically, when the dust presence / absence determination unit 305 determines that dust is attached to the optical element 302, the control unit 304 causes the vibration unit 303 to perform an excitation operation, and the dust presence / absence determination unit. When it is determined by 305 that dust is not attached on the optical element 302, the drive control is performed so that the vibration operation by the vibration means 303 is not performed.

  Therefore, according to the optical device with a dustproof function of the first embodiment, it is determined whether or not there is dust attached to the dustproof optical element 302 arranged in the optical path of the photographing optical system 300. Based on the result, drive control of the vibration means 303 as the dust removal means, for example, the dust removal operation by the vibration means 303 is performed only when it is determined that dust is present, so that when the power is turned on or the photographing interchangeable lens is attached Even when the dust is not attached to the dust-proof optical element 302, it is not necessary to perform the dust removal operation, so that power consumption can be reduced, battery consumption can be suppressed, Even when the removal operation is executed, the dust removal operation can be repeated until dust remains, and a reliable dustproof effect can be obtained.

  FIG. 2 is a block diagram showing a specific configuration example of a digital camera system in which the optical device with a dustproof function shown in FIG. 1 is mounted. This camera system is mainly composed of a lens unit 10 as an interchangeable lens and a body unit 100 as a camera body. A desired lens unit 10 is attached to and detached from the front surface of the body unit 100 via a mount 207. It is set freely.

  The lens unit 10 is controlled by a lens control microcomputer (hereinafter referred to as “Lucom”) 5. The control unit 304 controls the body unit 100 (in the following description, the control unit 304 is referred to as a body control microcomputer (hereinafter referred to as “Bucom”) 304) Note that these Lucom 5 and Bucom 304 are The electric connection is made through the communication connector 6 so as to be communicable at the time of combination. As a camera system, the Lucom 5 operates in cooperation with the Bucom 304 in a dependent manner.

  In the lens unit 10, a photographing lens 1 and a diaphragm 3 constituting a photographing optical system 300 are provided. The taking lens 1 is driven by a DC motor (not shown) in the lens driving mechanism 2. The diaphragm 3 is driven by a stepping motor (not shown) in the diaphragm driving mechanism 4. Lucom 5 controls each of these motors in accordance with commands from Bucom 304.

  The following structural members are arranged in the body unit 100 as shown in the figure. For example, a single-lens reflex type structural member (quick return mirror 11, pentaprism 12, eyepiece lens 13, submirror 14) as an optical system, a focal plane type shutter 15 on the optical axis, and a reflected light beam from the submirror 14 An AF sensor unit 16 for receiving and automatically measuring the distance is provided. In addition, an AF sensor driving circuit 17 for driving and controlling the AF sensor unit 16, a mirror driving mechanism 18 for driving and controlling the quick return mirror 11, and a shutter charging mechanism 19 for charging a spring for driving the front curtain and the rear curtain of the shutter 15. A shutter control circuit 20 that controls the movement of the front curtain and the rear curtain, and a photometric circuit 21 that performs photometric processing based on the light flux from the pentaprism 12 are provided.

  On the optical axis of the photographic optical system 300, there is provided a photoelectric conversion element 301 for photoelectrically converting the subject image that has passed through the optical system described above (hereinafter, the photoelectric conversion means 301 is referred to as a CCD unit 301). It is protected by an optical element 302 (hereinafter, the optical element 302 is referred to as dustproof glass 302) disposed between the CCD unit 301 and the taking lens 1. For example, the piezoelectric element 31 is attached to the periphery of the dust-proof glass 302 as a part of the vibration means 303 that vibrates the dust-proof glass 302 at a predetermined frequency. Further, the piezoelectric element 31 is configured to vibrate the dust-proof glass 302 by the dust-proof glass driving circuit 40 as a part of the vibration means, and to remove dust attached to the glass surface. Therefore, this camera system is an electronic camera (electronic imaging apparatus) having a basic structure belonging to a so-called “camera with dustproof function”. In order to measure the temperature around the CCD unit 301, a temperature measurement circuit 33 is provided in the vicinity of the dust-proof glass 302.

  This camera system is provided with an image processing controller 28 that performs image processing using a CCD interface circuit 23 connected to the CCD unit 301, a liquid crystal monitor 24, an SDRAM 25 provided as a storage area, a flash ROM 26, a recording medium 27, and the like. The electronic recording display function can be provided together with the electronic imaging function. As other storage areas, a nonvolatile memory 29 made of, for example, an EEPROM is provided as a nonvolatile storage means for storing predetermined control parameters necessary for camera control, and is accessible from the Bucom 304.

  The Bucom 304 is provided with an operation display LCD 51 and a camera operation SW 52 for notifying the user of the operation state of the camera by display output. The camera operation SW 52 is a switch group including operation buttons necessary for operating the camera, such as a release SW, a mode change SW, and a power SW. Further, a battery 54 as a power source and a power circuit 55 for converting the voltage of the power source into a voltage required for each circuit unit constituting the camera system and supplying the same are provided.

  In the camera system configured as described above, each unit operates as follows. The image processing controller 28 takes in image data from the CCD unit 301 by controlling the CCD interface circuit 23 in accordance with a command from Bucom 304. This image data is converted into a video signal by the image processing controller 28 and output and displayed on the liquid crystal monitor 24. The user can confirm the captured image from the display image on the liquid crystal monitor 24. The SDRAM 25 is a memory for temporarily storing image data, and is used as a work area when the image data is converted. The image data is set to be stored in the recording medium 27 after being converted into JPEG data.

  The CCD unit 301 is protected by a transparent dustproof glass 302. A piezoelectric element 31 for vibrating the glass surface is disposed on the periphery of the dust-proof glass 302. As will be described in detail later, the piezoelectric element 31 is driven by a dust-proof glass driving circuit 40 that also serves as a driving means for this purpose. It is more preferable for dust prevention that the CCD unit 301 and the piezoelectric element 31 are housed integrally in a case having the dust-proof glass 302 as one surface and surrounded by a frame as shown by a broken line.

  By the way, the temperature usually affects the elastic modulus of a glass material and is one of the factors that change its natural frequency. Therefore, the temperature is measured during operation and the change of its natural frequency is taken into account. There must be. It is better to estimate the natural frequency at that time by measuring the temperature change of the dust-proof glass 302 provided to protect the front surface of the CCD unit 301 where the temperature rises rapidly during operation. Therefore, a sensor (not shown) connected to the temperature measurement circuit 33 is provided for measuring the ambient temperature of the CCD unit 301. The temperature measurement point of the sensor is preferably set in the vicinity of the vibration surface of the dust-proof glass 302.

  The mirror driving mechanism 18 is a mechanism for driving the quick return mirror 11 to the UP position and the DOWN position. When the quick return mirror 11 is at the DOWN position, the light flux from the photographing lens 1 is the AF sensor unit 16. Side and the pentaprism 12 side. The output from the AF sensor in the AF sensor unit 16 is transmitted to the Bucom 304 via the AF sensor driving circuit 17 and a known distance measurement process is performed.

  Further, the eyepiece 13 adjacent to the pentaprism 12 allows the user to visually observe the subject, while part of the light beam that has passed through the pentaprism 12 is guided to a photosensor (not shown) in the photometry circuit 21 where it is detected. A well-known photometric process is performed based on the light quantity.

  Next, with reference to the circuit diagram of the dustproof glass driving circuit 40 shown in FIG. 3 and the time chart shown in FIG. 4, the driving of the dustproof glass 302 of the camera with the dustproof function and the operation control thereof in the first embodiment will be described. To do. The dust-proof glass driving circuit 40 illustrated here has a circuit configuration as shown in FIG. 3, and waveform signals (Sig 1 to Sig 6) shown in the time chart of FIG. 4 are generated at each part, and based on those signals. Is controlled as follows.

  That is, as illustrated in FIG. 3, the dust-proof glass driving circuit 40 includes an N-ary counter 41, a 1/2 frequency divider circuit 42, an inverter 43, a plurality of MOS transistors (Q00, Q01, Q02) 44a, 44b, 44c, A transformer 45 and a resistor (R00) 46 are included.

  It is configured such that a signal (Sig4) having a predetermined period is generated on the secondary side of the transformer 45 by the on / off switching operation of the transistor (Q01) 44b and the transistor (Q02) 44c connected to the primary side of the transformer 45. The piezoelectric element 31 is driven based on the signal of this predetermined period to resonate the dustproof glass 302 (details will be described later).

  The Bucom 304 controls the dust-proof glass driving circuit 40 through the two IO ports P_PwCont and IO port D_NCnt provided as control ports and the clock generator 55 existing inside the Bucom 304 as follows. The clock generator 55 outputs a pulse signal (basic clock signal) to the N-ary counter 41 at a frequency sufficiently faster than the signal frequency applied to the piezoelectric element 31. This output signal is a signal Sig1 having a waveform represented by the time chart in FIG. The basic clock signal is input to the N-ary counter 41.

  The N-ary counter 41 counts this pulse signal and outputs a count end pulse signal every time it reaches a predetermined value “N”. That is, the basic clock signal is divided by 1 / N. This output signal is a signal Sig2 having a waveform represented by the time chart in FIG. In this divided pulse signal, the duty ratio between High and Low is not 1: 1. Therefore, the duty ratio is converted to 1: 1 through the 1/2 frequency divider circuit. The converted pulse signal corresponds to the signal Sig3 having a waveform represented by the time chart in FIG.

  In the high state of the converted pulse signal, the MOS transistor (Q01) 44b to which this signal is input is turned on. On the other hand, this pulse signal is applied to the transistor (Q02) 44c via the inverter 43. Therefore, in the low state of the pulse signal, the transistor (Q02) 44c to which this signal is input is turned on. When the transistors (Q01) 44b and the transistors (Q02) 44c connected to the primary side of the transformer 45 are alternately turned on, a signal having a cycle such as the signal Sig4 in FIG. 5 is generated on the secondary side.

  The winding ratio of the transformer 45 is determined from the output voltage of the power supply circuit 55 and the voltage necessary for driving the piezoelectric element 31. The resistor (R00) 46 is provided to restrict an excessive current from flowing through the transformer 45.

  When the piezoelectric element 31 is driven, the transistor (Q00) 44a is in an on state, and a voltage must be applied from the unit of the power supply circuit 55 to the center tap of the transformer 45. In the figure, on / off control of the transistor (Q00) 44a is performed via the P_PwCont of the IO port. The set value “N” of the N-ary counter 41 can be set from the IO port D_NCnt. Therefore, the Bucom 333 can arbitrarily change the drive frequency of the piezoelectric element 31 by appropriately controlling the set value “N”.

At this time, the frequency can be calculated by the following equation (1).
fdrv = fpls / 2N (1)
Here, N: set value to the counter,
fpls: frequency of the output pulse of the clock generator,
fdrv: frequency of a signal applied to the piezoelectric element,
The calculation based on the equation (1) is performed by the CPU of Bucom 304.

  Next, the control performed by the camera body control microcomputer (Bucom) 304, which is the above-described control means, will be specifically described. FIG. 5 illustrates the main routine of the control program that runs on the Bucom 304. First, when the power SW (not shown) of the camera is turned on, the Bucom 304 starts operation, and in step S000, processing for starting the camera system is executed. The power supply circuit 55 is controlled to supply power to each circuit unit constituting this camera system. Also, initial setting of each circuit is performed.

  In the next step S001, the state of the camera operation SW 52 is detected. In this detection process, when an operation of a mode change SW (not shown) which is one of the camera operations SW is detected (step S002: Yes), the process proceeds to step S003. In step S003, it is determined whether or not a dust check / removal SW (not shown), which is one of a plurality of mode change SWs, has been operated. When the dust check / removal SW is operated (step S003: Yes), the process proceeds to step S004. When the dust check / removal SW is not operated (step S003: No), the process proceeds to step S005. In step S004, a subroutine “dust detection / removal” is executed (details will be described later), and then the process returns to step S001. On the other hand, in step S005, the operation mode of the camera is changed in conjunction with the operated SW. In step S006, information corresponding to the operation mode is displayed and output to the operation display LED 51, and then the process returns to step S001.

  In step S007, 1st. It is determined whether a release SW (not shown) has been operated. If 1st. If the release SW is on, the process proceeds to step S008, and if it is off, the process proceeds to step S001 again. In step S008, the luminance information of the subject is obtained from the photometry circuit 21. Then, the exposure time (Tv value) of the CCD unit 301 and the aperture setting value (Av value) of the photographing lens 1 are calculated from this information.

  In step S 009, the detection data of the AF sensor unit 16 is obtained via the AF sensor drive circuit 17. Based on this data, the amount of focus shift is calculated. In step S010, the amount of focus shift is transmitted to Lucom 5, and the driving of the photographing lens 1 is instructed based on this amount of shift. In step S011, 2nd. It is determined whether a release SW (not shown) has been operated. This 2nd. When the release SW is on, the process proceeds to step S012, and a predetermined photographing operation is performed. When the release SW is off, the process proceeds to step S001 again.

  From step S012, first, the Av value is transmitted to Lucom 5 to instruct to drive the diaphragm 3, and in step S013, the quick return mirror 11 is moved to the up position. In step S014, the front curtain travel of the shutter 15 is started, and in step S015, the image processing controller 28 is instructed to execute an imaging operation. When the exposure to the CCD unit 303 is completed for the time indicated by the Tv value, the rear curtain travel of the shutter 15 is started in step S016, and the quick return mirror 11 is driven to the down position in step S017.

  In parallel with this, the shutter 15 is charged. In step S018, Lucom 5 is instructed to return the diaphragm 3 to the open position, and in step S019, the image processing controller 28 is instructed to record the captured image data on the recording medium 27. . When the recording of the image data is completed, the process proceeds to step S001 again.

  Next, a processing control example of the subroutine “dust detection / removal” in step S004 will be described. FIG. 6 is a schematic flowchart showing a processing control example of the subroutine “dust detection / removal”. First, in step S400, a command is transmitted from Bucom 304 to Lucom 5, and the focus of the photographing lens 1 is driven to a predetermined position such as an optical infinite position, for example. In step S401, an instruction is transmitted from Bucom 304 to Lucom 5, and the aperture of the photographing lens 1 is narrowed down to a predetermined FNo. This is to increase the depth of field in order to facilitate the detection of dust.

  In step S402, a mirror-up operation is performed to drive the quick return mirror 11 to the shooting position. In step S403, shutter open control is performed and the shutter 15 is opened. At this time, the camera is in a so-called valve state. In step S404, the through image is turned on, and the image acquired by the CCD unit 301 is displayed on the liquid crystal monitor 24 on the rear surface. From here, the photographing operation is repeated, and the image is updated and displayed on the liquid crystal monitor 24 every time the image is acquired.

  In step S405, it is determined whether the dust check / removal SW has been operated. When the dust check / removal SW is operated (step S405: Yes), the process proceeds to step S406, and the subroutine “dust detection” is performed. On the other hand, when the dust check / removal SW is not operated (step S405: No), the process proceeds to step S415, and it is determined whether or not a predetermined time has elapsed. Here, the operation of the dust check / removal SW is waited for a predetermined time after shifting to the dust detection / removal mode. This is because in order to make it easier to detect dust, the photographer needs to point the camera toward a medium-high brightness uniform subject having a substantially uniform brightness distribution. When the setting is completed, the dust check / removal SW is operated. In order to perform the dust detection / removal operation. Here, the medium / high brightness uniform subject includes, for example, a light box (brightness box) 310 as shown in FIG. 7, a blue sky, a white subject for white balance, and the like. In FIG. 7, 311 is a camera body, and 312 is a tripod.

  When the dust check / removal SW is operated (step S405: Yes) and the subroutine “dust detection” is performed (step S406), in step S407, it is determined whether dust attached to the dustproof glass 302 exists. To do. When it is determined that there is dust adhering (step S407: Yes), the process proceeds to step S408, and an image showing a portion where the detected dust is located is displayed on the liquid crystal monitor 24. FIG. 8 is a diagram showing an example of this display example. A dust image 321 is displayed on the liquid crystal monitor 24 with a marker display 322. At this time, if an enlarged display function of the liquid crystal monitor 24 of the camera is used, an image with dust attached can be enlarged and observed.

  In step S409, current temperature data from the temperature measurement circuit 33 is captured. This temperature data is necessary data in the next subroutine “dust removal” operation. In step S410, the subroutine “dust removal” is executed (details will be described later). In the subroutine “dust removal”, the dust-proof glass 302 is vibrated to perform dust removal operation. The manner in which dust is removed by this dust removal operation is displayed on the liquid crystal monitor 24, so that it can be visually confirmed.

  In step S411, the number of repeated dust removal operations is stored, and it is determined whether or not a predetermined number of dust removal operations have been performed. If the dust removal operation has not been performed a predetermined number of times (step S411: No), the process returns to step S406 to execute the subroutine “dust removal” again. As described above, when the detected dust is not removed, the dust removing operation is repeatedly performed until the dust is removed.

  If the dust removal operation has been performed a predetermined number of times (step S411: Yes), it is determined that the dust cannot be removed by the dust removal operation, and the process proceeds to step S412 to create pixel defect correction data. That is, the dust in such a case is a pixel defect of the CCD unit 301 or dust directly attached on the CCD unit 301, so that the dust cannot be removed by the dust removing operation on the dust-proof glass 302. In this case, the pixel information of the dust adhering portion is estimated from the information of the surrounding pixels, and pixel defect correction for creating pixel information is performed. Pixel defect correction is performed with reference to the dust position and correction data, which are pixel defect information, to prevent image quality deterioration due to dust. In step S413, the liquid crystal monitor 24 displays that the dust cannot be removed to notify the photographer.

  On the other hand, if it is determined that there is no dust adhering to the dust-proof glass 302 (step S407: No), the process proceeds to step S414, and the fact that no dust is present is displayed on the liquid crystal monitor 24 to notify the photographer. To finish the process. In addition, even if dust is detected once, if the result of subsequent dust removal operation and dust detection is that there is no dust, it means that the dust has been removed, so the dust is removed. Is displayed on the liquid crystal monitor 24 to inform the photographer and the process is terminated.

  Furthermore, when the predetermined time has passed without the dust check / removal SW being operated (step S415: Yes), the process proceeds to step S416, and the through image display by the liquid crystal monitor 24 is turned off. In step 417, the shutter close operation is performed and the shutter 15 is closed. In step S418, mirror down / shutter charge control is performed, the quick return mirror 11 is driven to the photographing preparation position, and the shutter 15 is charged. .

  Next, a processing control example of the subroutine “dust detection” in step S406 will be described. FIG. 9 is a schematic flowchart showing a process control example of the subroutine “dust detection”. When the subroutine “dust detection” is called, first, in step S301, an image is acquired. The image acquisition method is not directly related to the present invention and will not be described in detail. However, the image processing controller 28 is instructed to control the CCD interface circuit 23 to acquire image data from the CCD unit 301 and store it in the SDRAM 25. . At this time, since the camera is in a valve state, the electronic shutter function of the CCD unit 301 is controlled to perform an accumulation operation, and image data is acquired. In this image acquisition process, an image obtained by acquiring a plurality of frames and averaging each pixel data is used in order to eliminate repeated variations.

  Here, an operation of performing dust detection from the acquired image data will be described. The pixel arrangement of the CCD unit 301 is a so-called Bayer arrangement. FIG. 10A shows the acquired image data as a Bayer image. Note that an OB value is acquired from an OB (optical black) area in the image data of the CCD unit 301, and the average value is subtracted from each pixel data.

  Hereinafter, the dust detection method of the first embodiment will be described. In general, in a specified part of all image data, the central luminance and the peripheral luminance obtained from the pixel data of the central portion (predetermined pixel region) and the pixel data of the peripheral portion (peripheral region), respectively. If the difference is greater than a predetermined value, it is determined that dust is present. By checking such determination over all pixel data, the presence of dust is determined over the entire screen.

This will be described in more detail with reference to FIGS. 10-1 and 10-2. FIG. 10A is an explanatory diagram of an example of the arrangement of the designated central part and peripheral part. The central part is composed of a predetermined number of pixels. Further, the peripheral part is composed of a predetermined number of pixels which are pixels around the central part that is separated from the central part by a predetermined number of pixels. Using the pixel data in each of the central part and the peripheral part, the average luminance is
Average brightness = 0.3 x R + 0.58 x G + 0.1 x B
Calculate according to Here, R, G, and B respectively indicate pixel data of R pixels, G pixels, and B pixels in a Bayer array.

After calculating the central average brightness and the peripheral average brightness, the dust level as an index indicating the presence of dust,
Dust level = | Average brightness at the center-Average brightness at the periphery |
Calculate according to The dust level obtained in this way is compared with a predetermined dust judgment value, and if it is larger than the dust judgment value, it is judged that dust is present. The dust determination value used for comparison is written and stored in the nonvolatile memory (EEPROM) 29 at the time of camera manufacture.

  Then, as shown in FIG. 10-2, such a detection method shifts the focused central part by a predetermined number of pixels while changing the position, for example, the central part 1, the peripheral part 1 → the central part 2, and the peripheral part 2. By repeatedly executing, it is possible to determine whether dust is present over the entire screen.

  Steps S302 to S308 in the flowchart of FIG. 9 show an example of such processing. That is, in step S302, the average luminance of the designated central portion is calculated, in step S303, the average luminance of the designated peripheral portion is calculated, and in step S304, the dust level of the designated portion is calculated. In step S305, it is determined whether or not the calculated dust level exceeds a predetermined dust semi-lowland. When the dust level is larger than the dust determination value (step S305: Yes), the process proceeds to step S306, and the position of the designated portion, that is, the dust position and the dust level are stored. Next, in step S307, the designated position is sequentially changed, and in step S308, it is determined whether or not the processing for all the screens is completed according to the designated position. If completed (step S308: Yes), the dust detection process is terminated. If not completed (step S308: No), the process returns to step S302.

  As described above, by executing the subroutine “dust detection”, it is determined whether dust is present over the entire screen, and if dust is present, the position in the screen and the dust level are stored. be able to.

  In this manner, when the acquired dust position and dust level data are plotted on the entire screen, a dust distribution diagram as shown in FIG. 11 is obtained. For example, in the case where positions having high numerical values of dust levels are adjacent to each other, the dust is relatively large like the large dust A in FIG. If present, it can be recognized as a relatively small dust such as the small dust B in FIG. Therefore, it is possible to obtain information indicating what kind of dust is present at which position.

  Here, the support structure and vibration mode of the dust-proof glass 302 will be described. In the camera system according to the present invention, the shape of the dust-proof glass 302 is assumed to be a disk. Further, when the piezoelectric element 31 for vibration is arranged along the circumference of the glass plate of the dustproof glass 302, the glass plate is supported on the circumference. At this time, the glass plate is vibrated in a plurality of vibration modes (vibration modes). In the present invention, two modes are selected from these vibration modes and used separately. FIGS. 12-1, 12-2, 13-1 and 13-2 show the vibration state of the glass plate in the selected vibration mode.

  The dust-proof glass 302 according to the first embodiment shows a vibration mode as illustrated in FIGS. 12-1 and 12-2. That is, when vibration is applied by the piezoelectric element 31 functioning as a vibration means, “nodes” that do not vibrate are generated around the glass plate, but the entire glass surface is generally in the same phase as indicated by the thick arrows. It vibrates by repeating the states of FIGS. 12-1 and 12-2 alternately. Such a vibration mode is hereinafter referred to as “vibration mode 1”.

  Similarly, the dust-proof glass 302 of the first embodiment can also vibrate in the form shown in FIGS. 13-1 and 13-2, depending on the frequency of vibration applied. That is, the vibration mode of the dust-proof glass 302 illustrated in FIGS. 13A and 13B is that the glass plate vibrates at a phase shifted by 180 degrees. Specifically, in the illustrated vibration mode, nodes are generated around and inside the glass plate. As shown in the figure, the vibration in the region surrounded by the inner node and the outer region of the inner node (the donut-shaped region) ) Is 180 degrees out of phase. Hereinafter, this is referred to as “vibration mode 2”.

  Next, in the subroutine “dust removal operation” shown in FIG. 14, the piezoelectric element 31 is set to be driven so that the dust-proof glass 302 is resonated in these two modes of vibration mode 1 and vibration mode 2. . Generally, the frequency and amplitude at which dust is easily removed vary depending on the characteristics of the dust (for example, weight, shape, material, etc.). Therefore, in order to remove dust reliably, the glass plate should be resonated in these two vibration modes. Of course, you may resonate in more than one vibration mode. However, since the time required for the removal operation may also be increased by that amount, an appropriate number should be set in consideration of the degree of the removal effect and the required time.

  The “dust removal operation” will be described based on the flowchart of FIG. 14 and FIGS. 15 to 18. First, in step S100, three control parameters (Startoffset, Stopoffset, OSCtime) are read from the EEPROM 29. These three control parameters can be read from the “vibration mode 1 temperature correction table” stored in the EEPROM 29 shown in the memory map of FIG.

  FIG. 16A shows the details of the vibration mode 1 compatible temperature correction table. In order to read out the corresponding control parameter from this temperature correction table, temperature information (t) is required. The temperature information (t) is detected and acquired by a temperature sensor (not shown) of the temperature measurement circuit 33 before executing this subroutine (see step S409 in FIG. 6).

  If the temperature information (t) is 20 ° C., the reading start position (Startoffset) is “3” when the control parameter at this time is read from the portion indicated by * 0 in the vibration mode 1 compatible temperature table of FIG. The read end position (Stopoffset) is “9”, and the time interval (OscTime) is “100”. Then, the area of the frequency correction table corresponding to the vibration mode 1 of the EEPROM 29 is defined by the value of “Startoffset” and the value of “Stopoffset”. Further, the N-ary counter 41 is sequentially set at the time interval read from this area (in this case, 100 msec.).

  17-1 and 17-2 show frequency correction tables corresponding to these vibration modes, FIG. 17-1 is a frequency correction table corresponding to vibration mode 1, and FIG. 17-2 is a frequency correction table corresponding to vibration mode 2. The frequency correction table corresponding to the vibration mode 1 is calculated on the assumption that the clock generator 55 outputs a pulse signal having a frequency of 40 (MHz).

  The drive frequency can be calculated by applying the formula (1) already described. Based on the values read from the temperature correction table described above, seven preset values in the areas * 1 to * 2 of the vibration mode 1 frequency correction table are sequentially set in the N-ary counter 41. When the relationship between the drive frequencies f1, f2,..., F7 at this time and the amplitude of vibration of the glass plate is plotted as a graph, a curve such as * 3 in FIG.

  In FIG. 18, the relationship between the drive frequency fn and the vibration amplitude of the glass plate is represented by a characteristic graph curve. The resonance frequency correction range (fc ′ <fc) centered on the plotted * 3 graph curve. <Fc ″) is shown. In the graph curve of * 3, fc is the resonance frequency. This fc happens to be equal to f4. For example, in the case of a glass plate having characteristics such as * 4, fc ′ is the resonance frequency, and fc ′ is equal to f3. For example, in the case of a glass plate having a characteristic such as * 5, fc ″ is the resonance frequency, and fc ″ is equal to f5.

  Therefore, in consideration of the fact that the resonance frequency varies within the range of Δfc, if the reading start position (Startoffset) and the reading end position (Stopoffset) of the frequency correction table are set, the glass plate is always vibrated at the resonance frequency. Can be realized. Further, even if Δfc varies depending on the temperature, it is obvious that the driving can be always performed at the resonance frequency by appropriately setting the temperature correction table corresponding to vibration mode 1 shown in FIG.

  Now, the description returns to the flowchart of FIG. If the value of OSCtime is increased, the excitation time in the resonance state can be arbitrarily set. However, it should be noted that the time for the invalid excitation operation (driving at a frequency other than the resonance frequency) also increases. Therefore, in step S101, Address M1 + Startoffset is set as the read start address of the EEPROM 29. Address M1 indicates the head address of the vibration mode 1 frequency correction table. Therefore, Address M1 + Startoffset corresponds to * 1 in FIG.

  In step S102, a preparatory operation for driving the piezoelectric element 31 is performed. The transistor (Q00) 44a is turned on by controlling P_PwCont of the IO port. Further, output of a pulse signal from the clock generator 55 is started. If the data extracted from the table is set in the N-ary counter 41 in this state, the piezoelectric element 31 can be driven at a desired frequency.

  In step S103, the preset value (N) is read from the set address. Then, the preset value read from the D_NCnt of the IO port to the N-ary counter 41 is set. In step S104, OSCtime is set in the timer counter, and the timer count operation is started.

  In step S105, the process waits until the operation of the timer counter is completed. In step S106, it is determined whether the address of the EEPROM 29 is equal to “Address M1 + Stopoffset”. If they are equal, it means that the table data has been read up to * 2 in FIG. That is, the excitation operation at a plurality of scheduled frequencies is completed. Therefore, in this case, a process for stopping the driving operation is performed in step S108. The transistor (Q00) 44a is turned off, and the operation of the clock generator 55 is stopped.

  When the process proceeds from step S106 to step S107, the address of the EEPROM 29 is incremented (+1). In order to drive the piezoelectric element 31 at the next frequency, the process proceeds to step S103 again.

  When the driving operation corresponding to the vibration mode 1 is completed, the operations of Steps S200 to S208 are performed for the driving operation corresponding to the vibration mode 2. Control parameters Startoffset, Stopoffset, and OSCtime necessary for exciting the glass plate in the vibration mode 2 may be read from the temperature correction table corresponding to vibration mode 2 shown in FIG. The preset value (N) may be read from the frequency correction table corresponding to the vibration mode 2 of the EEPROM 29. Similarly, details of the frequency correction table corresponding to vibration mode 2 are shown in FIG.

  The subsequent operations in steps S200 to S208 are basically the same as the operations in steps S100 to S108 described above. The only difference is that the address of the EEPROM 29 from which the table necessary for control is read is different. Therefore, the description is omitted.

  Thus, when the vibration operation to the dust-proof glass 302 in the two vibration modes of vibration mode 1 and vibration mode 2 is completed, the process returns to the main routine.

  It should be noted that it is very difficult to predict variations in the resonance frequency of the glass plate at the design stage of the camera system. Therefore, it should be possible to set a control parameter for determining the drive frequency of the piezoelectric element 31 after the camera system is completed. Therefore, all necessary parameters are stored in the EEPROM 29 so as to be selectable in the present invention as described above.

  As described above, according to the digital camera system that is the optical device with the dustproof function of the first embodiment, whether or not dust is attached to the dustproof glass 302 in the photographing optical path is determined using the output of the CCD unit 301. Only when there is dust, the dust removal operation is performed on the dust-proof glass 302, so that power consumption can be reduced and battery consumption can be suppressed. Moreover, since it can also be confirmed whether dust was removed by dust removal operation | movement, a reliable dustproof effect can be acquired.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIGS. FIG. 19 is a schematic flowchart showing a processing example of a subroutine “dust removal” operation according to the second embodiment. In the second embodiment, before the subroutine “dust removal” as shown in FIG. 14 is executed in step S502, the dust removal parameter setting process is performed in step S501 in accordance with the dust detection result. This is different from the first embodiment.

  FIG. 20 is a schematic flowchart illustrating an example of a dust removal parameter setting process executed in step S501. Here, an operation of changing the vibration time of the dust-proof glass 302 by the piezoelectric element 31 as a parameter is performed according to the detected dust size, the number of dusts, and the dust location. The vibration time is the OSCtime shown in steps S104 and S204 during the subroutine “dust removal” shown in FIG. 14 and in FIGS. 16-1 and 16-2.

  First, in step S511, it is determined whether or not the size of the detected dust is larger than a predetermined determination value. If the result of determination is greater than the determination value (step S511: Yes), the process proceeds to step S512, and the excitation time is set to four times the initial value. This is because dust is relatively large and difficult to remove, so that the vibration time is prolonged and dust is reliably removed.

  If the size of the dust is less than or equal to the determination value (step S511: No), the process proceeds to step S513, and it is determined whether or not the total number of detected dust is greater than a predetermined determination value. As a result of the determination, if it is larger than the determination value (step S513: Yes), the process proceeds to step S514, and the excitation time is set to three times the initial value. This is because the amount of dust is relatively large, and thus the dust is reliably removed by extending the excitation time.

  If the number of dusts is less than or equal to the determination value (step S513: No), the process proceeds to step S515, and it is determined whether or not the detected dust is located at the center determined by a predetermined method. . As a result of the determination, if it is located at the center (step S515: Yes), the process proceeds to step S516, and the excitation time is set to twice the initial value. It can be said that the influence of dust adhesion on the captured image is larger when the dust is present in the center than in the peripheral part. This is to remove dust.

  On the other hand, when dust is present only in the peripheral part (step S515: No), the influence on the image quality is relatively small, so the excitation time is left at the initial value.

  According to the second embodiment, when dust is detected, the excitation time for vibrating the dust-proof glass 302 by the piezoelectric element 31 is changed according to the size of the dust, the number of dusts, and the location of the dust. Therefore, the dust removal operation according to the state of the attached dust is possible, and the dust can be removed more reliably.

(Embodiment 3)
A third embodiment of the present invention will be described with reference to FIG. Similarly to the second embodiment, the third embodiment also performs the dust removal parameter setting process according to the dust detection result before executing the subroutine “dust removal” as shown in FIG. However, the parameter setting is the number of repetitions of the dust removal operation instead of the vibration time.

  FIG. 21 is a schematic flowchart showing an example of the dust removal parameter setting process of the third embodiment which is executed in step S501 shown in FIG. Here, an operation of changing the number of repetitions of performing the dust removal operation as a parameter is performed in accordance with the detected size of the dust, the number of dusts, and the presence position of the dust. The number of repetitions means the predetermined number in step S411 that defines the number of times the dust detection to dust removal operations in steps S406 to S410 in FIG. 6 are repeated.

  First, in step S521, it is determined whether or not the size of the detected dust is larger than a predetermined determination value. If the result of determination is greater than the determination value (step S521: Yes), the process proceeds to step S522, and the number of repetitions is set to four times the initial value. This is because dust is relatively large and difficult to remove, so the number of repetitions is increased to reliably remove dust.

  When the size of the dust is equal to or smaller than the determination value (step S521: No), the process proceeds to step S523, and it is determined whether or not the total number of detected dust is larger than a predetermined determination value. As a result of the determination, if it is larger than the determination value (step S523: Yes), the process proceeds to step S524, and the number of repetitions is set to three times the initial value. This is because dust is relatively removed, and the dust is reliably removed by increasing the number of repetitions.

  When the number of dusts is less than or equal to the determination value (step S523: No), the process proceeds to step S525, and it is determined whether or not the detected dust is located at the center determined by a predetermined method. . As a result of the determination, if it is located at the center (step S525: Yes), the process proceeds to step S526, and the number of repetitions is set to twice the initial value. This is because the effect of dust adhesion on the captured image is greater when the dust is present in the center than in the periphery. It is for removing.

  On the other hand, when dust is present only in the peripheral part (step S525: No), since the influence on the image quality is relatively small, the number of repetitions remains the initial value.

  According to the third embodiment, when dust is detected, the number of repetitions of the dust detection to dust removal operation is changed according to the size of the dust, the number of dusts, and the location of the dust. The dust removal operation according to the state of the dust is possible, and the dust can be more reliably removed.

(Embodiment 4)
A fourth embodiment of the present invention will be described with reference to FIGS. In the fourth embodiment, similarly to the second and third embodiments, before executing the subroutine “dust removal” as shown in FIG. 14, the dust removal parameter setting process is performed according to the dust detection result. The parameter setting is applied voltage applied to the piezoelectric element 31 instead of the vibration time and the number of repetitions.

  FIG. 22 is a schematic flowchart showing an example of the dust removal parameter setting process of the fourth embodiment that is executed in step S501 shown in FIG. Here, the vibration amplitude of the dust-proof glass 302 as a parameter, that is, the applied voltage applied to the piezoelectric element 31 by the dust-proof glass driving circuit 40 is changed according to the size of the detected dust, the number of dusts, and the location of the dust. To perform the operation.

  First, in step S531, it is determined whether or not the size of the detected dust is larger than a predetermined determination value. If the result of determination is greater than the determination value (step S531: Yes), the process proceeds to step S532, where the applied voltage is set to four times the initial value. This is because dust is relatively large and difficult to remove, so that the applied voltage is increased to increase the vibration amplitude of the dust-proof glass 302, thereby reliably removing dust.

  If the size of the dust is less than or equal to the determination value (step S531: No), the process proceeds to step S533, and it is determined whether or not the total number of detected dust is greater than a predetermined determination value. As a result of the determination, if it is greater than the determination value (step S533: Yes), the process proceeds to step S534, and the applied voltage is set to three times the initial value. This is because dust is relatively removed, so that the applied voltage is increased to increase the vibration amplitude of the dust-proof glass 302 and the dust is reliably removed.

  When the number of dusts is equal to or less than the determination value (step S533: No), the process proceeds to step S535, and it is determined whether or not the detected dust is located at the center determined by a predetermined method. . As a result of the determination, when it is located at the center (step S535: Yes), the process proceeds to step S536, and the applied voltage is set to twice the initial value. This is because the influence of dust adhesion on the photographed image is greater when the dust is present at the center than when the dust is present at the center. This is to make the vibration amplitude slightly larger and to reliably remove dust.

  On the other hand, when dust is present only in the peripheral part (step S535: No), the applied voltage remains at the initial value because the influence on the image quality is relatively small.

  FIG. 23 is a schematic block diagram illustrating a circuit configuration example including a dustproof glass driving circuit 40 configured to be able to vary the voltage applied to the piezoelectric element 31. An applied voltage switching signal (H / L) from Bucom 304 is input to the power supply circuit 55, and it is possible to switch the power supply voltage to the dustproof glass driving circuit 40 in two stages (H / L) by this switching signal. ing. For example, when the applied voltage switching signal is set to H level and the power supply voltage of the dustproof glass driving circuit 40 is set to high level, the primary side voltage of the transformer 45 becomes higher, and the secondary side corresponding to the winding ratio of the transformer 45 It is possible to increase the voltage applied to the piezoelectric element 31 generated in the above. When the voltage applied to the piezoelectric element 31 is increased, the vibration amplitude of the dust-proof glass 302 is increased, so that dust can be more easily removed.

  According to the fourth embodiment, when dust is detected, the applied voltage applied to the piezoelectric element 31 by the dustproof glass driving circuit 40 is changed according to the size of the dust, the number of dusts, and the location of the dust. Since the vibration amplitude of the dust-proof glass 302 is changed, the dust removal operation according to the state of the attached dust is possible, and the dust can be more reliably removed.

(Embodiment 5)
A fifth embodiment of the present invention will be described with reference to FIGS. 24 and 25. FIG. In the fifth embodiment, similarly to the second to fourth embodiments, before executing the subroutine “dust removal” as shown in FIG. 14, the dust removal parameter setting process is performed according to the dust detection result. The parameter setting is performed within the range of the excitation frequency.

  FIG. 24 is a schematic flowchart showing an example of the dust removal parameter setting process of the fifth embodiment that is executed in step S501 shown in FIG. Here, the operation of changing the range of the excitation frequency as a parameter is performed in accordance with the size of the detected dust, the number of dusts, and the position where dust is present. That is, the drive frequency for exciting and driving the dust-proof glass 302 is changed. As a range of this drive frequency, in the fifth embodiment, as shown in FIG. 25, * 1 (f1) to * 2 Two patterns can be set: pattern 1 in the range indicated by (f7) and pattern 2 in the range indicated by * 3 (f3) to * 4 (f5). The initial value is set in the frequency range of pattern 1.

  First, in step S541, it is determined whether or not the size of the detected dust is larger than a predetermined determination value. As a result of the determination, if the size of the dust is equal to or smaller than the determination value (step S541: No), the process proceeds to step S543 to determine whether the total number of detected dust is greater than a predetermined determination value. . As a result of the determination, if the number of dusts is less than or equal to the determination value (step S543: No), the process proceeds to step S545, and whether or not the detected dust is located at the center determined by a predetermined method. Determine whether. As a result of the determination, when the dust is not located in the central portion and dust is present only in the peripheral portion (step S545: No), the driving frequency range is set to the pattern 2 that is ½ times the initial value. . In other cases (steps S541: Yes, S543: Yes, S545: Yes), the drive frequency range remains the initial value (pattern 1).

  This is because the influence of dust adhesion on the dustproof glass 302 on the image is larger as the size of the dust, the total number of dusts, and the dust in the center of the screen are larger. In this case, the range of the driving frequency is widened as the initial value so that the dust removal operation is performed reliably. On the other hand, if the size of the dust and the total number of dust are relatively small and dust is present only in the periphery of the screen, the degree of influence on image quality will be low, so the drive frequency range will be lower than the initial value. By setting the narrow pattern 2, the power consumption can be reduced.

(Embodiment 6)
A sixth embodiment of the present invention will be described with reference to FIGS. 26 and 27. FIG. In the sixth embodiment, similarly to the second to fifth embodiments, the dust removal parameter is set before the subroutine “dust removal” is executed. Accordingly, the vibration mode (vibration mode) is changed and set as a dust removal parameter. The vibration mode means the vibration operation of the dustproof glass 302 shown in FIGS. 11-1 to 12-2.

  FIG. 26 is a schematic flowchart showing a processing example of the dust removal parameter setting according to the sixth embodiment, which is executed in step S501 shown in FIG. First, when the presence of dust is detected, it is determined in step S551 whether or not the dust location is a position close to a node in the vibration mode 2 of the dust-proof glass 302. When it exists in the position close | similar to a node (step S551: Yes), it transfers to step S552 and the operation flag for performing only the vibration mode 1 is set. This is because when vibration is present near the node of vibration mode 2, vibration mode 2 is not effective in vibration mode 2 because the vibration amplitude near the node is very small and is not effective. To do. On the other hand, when it does not exist at a position close to the node (step S551: No), the process proceeds to step S553, and an operation flag for executing both vibration modes 1 and 2 which are the initial values is set.

  FIG. 27 is a flowchart showing a processing example of a dust removal subroutine of the sixth embodiment that is executed in place of FIG. 14 in step S502 shown in FIG. This process is the same as that shown in FIG. 14, but after the dust removal operation in the vibration mode 1 is completed (step S108), it is determined whether or not the vibration mode 2 is executed with reference to the flag ( Step S199), in the case of setting the flag that does not execute the vibration mode 2 by the setting process of Step S552 (Step S199: No), the processing in FIG. Different.

  According to the sixth embodiment, when dust is detected, whether to perform only vibration mode 1 or both vibration modes 1 and 2 is changed according to the position of the dust. Therefore, it is possible to perform a dust removal operation without waste of power consumption according to the state of attached dust, and dust can be reliably removed.

  The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

It is a conceptual schematic block diagram which mainly shows the control system corresponding to the example of a principal part structure of the digital camera system as an optical apparatus with a dustproof function of Embodiment 1 of this invention. It is a block block diagram which shows the specific structural example as a digital camera system carrying the optical apparatus with a dustproof function shown in FIG. It is a circuit diagram which shows the structural example of the dust-proof glass drive circuit with respect to a piezoelectric element. It is a time chart which shows the example of operation control. It is a flowchart which shows the main routine of a control program. It is a flowchart showing the detailed procedure of the subroutine "dust detection / removal" in the flowchart of FIG. It is a schematic perspective view which shows the mode at the time of light box imaging | photography. It is a figure which shows the example of a display of the part in which the detected dust is located. It is a flowchart showing the detailed procedure of the subroutine "dust detection" in the flowchart of FIG. It is explanatory drawing which shows an example of arrangement | positioning of the designated center part and peripheral part with a Bayer image. It is explanatory drawing which shows a mode that the pixel position was shifted. It is a dust distribution map which shows the result of having plotted the position and dust level data where the acquired dust exists with respect to the whole screen. It is explanatory drawing of the one aspect | mode of the vibration mode 1 which shows the vibration form of the dust-proof glass which concerns on this invention, a node generate | occur | produces around a glass plate, and the whole surface vibrates with the same phase. It is explanatory drawing of the different aspect of the vibration mode 1 which shows the vibration form of the dust-proof glass based on this invention, and a node generate | occur | produces around a glass plate and the whole surface vibrates with the same phase. It is explanatory drawing of the one aspect | mode of the vibration mode 2 which shows the vibration form of the dust-proof glass which concerns on this invention, and vibrates with the phase different 180 degrees inside and outside of a glass plate. It is explanatory drawing of the different aspect of the vibration mode 2 which shows the vibration form of the dust-proof glass which concerns on this invention, and vibrates with the phase which the inner side and outer side of a glass plate differ 180 degrees. It is a flowchart showing the detailed procedure of the subroutine "dust removal operation" in the flowchart of FIG. It is a memory map which shows the table area | region regarding the correction | amendment occupied to EEPROM. It is a figure which shows the detail of a vibration mode 1 corresponding | compatible temperature correction table. It is a figure which shows the detail of a vibration mode 2 corresponding | compatible temperature correction table. It is a figure which shows the detail of a vibration mode 1 corresponding | compatible frequency correction table. It is a figure which shows the detail of a vibration mode 2 corresponding | compatible frequency correction table. It is a characteristic graph showing the relationship between a drive frequency and the amplitude of the vibration of a glass plate. It is a schematic flowchart which shows the process example of the subroutine "dust removal" operation | movement of Embodiment 2 of this invention. It is a schematic flowchart which shows an example of the process example of the dust removal parameter setting performed by step S501 shown in FIG. FIG. 20 is a schematic flowchart illustrating a processing example of dust removal parameter setting according to the third embodiment of the present invention executed in step S501 shown in FIG. FIG. 20 is a schematic flowchart illustrating a processing example of dust removal parameter setting according to the fourth embodiment of the present invention, which is executed in step S501 shown in FIG. It is a schematic block diagram which shows the circuit structural example containing a dust-proof glass drive circuit. It is a schematic flowchart which shows the process example of the dust removal parameter setting of Embodiment 5 of this invention performed by step S501 shown in FIG. It is a figure which shows the detail of a vibration mode 1 corresponding | compatible frequency correction table. It is a schematic flowchart which shows the process example of the dust removal parameter setting of Embodiment 6 of this invention performed by step S501 shown in FIG. It is a schematic flowchart which shows the example of a subroutine dust removal process of Embodiment 6 of this invention performed by step S502 shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 31 Piezoelectric element 40 Dust-proof glass drive circuit 300 Shooting optical system 301 Photoelectric conversion element 302 Optical element 303 Excitation means 304 Control means 305 Dust presence / absence discrimination means

Claims (13)

A photoelectric conversion element that receives an optical image of a subject formed by the photographing optical system and converts it into an electrical signal;
A dust-proof optical element disposed on the photographing optical path preceding the photoelectric conversion element;
Dust presence / absence discriminating means for discriminating whether dust attached on the optical element or other foreign matter is present based on the output of the photoelectric conversion element;
Dust removing means for removing dust attached to the optical element and other foreign matters;
Control means for driving and controlling the dust removing means based on the determination result of the dust presence / absence determining means;
An optical device with a dustproof function.   The control means causes the dust removal means to perform a dust removal operation when the dust presence / absence determination means determines that there is a foreign object, and when the dust presence / absence determination means determines that no foreign substance exists. The optical device with a dustproof function according to claim 1, wherein the drive control is performed so as not to perform the dust removal operation by the dust removal means.   When the control means determines that there is a foreign object by the dust presence / absence determining means, after the dust removal means performs a dust removal operation and then determines again that the foreign substance exists by the dust presence / absence determining means The dust removal means performs the dust removal operation again, and when the dust presence / absence judgment means determines that there is no foreign matter, the drive control is performed so that the dust removal action is not performed by the dust removal means. The optical device with a dustproof function according to claim 1.   The control means, when it is determined by the dust presence / absence determination means that foreign matter is present, changes an operation parameter in accordance with a dust detection result and causes the dust removal means to perform a dust removal operation. The optical device with a dustproof function according to any one of claims 1 to 3.   The optical device with a dustproof function according to claim 4, wherein the dust detection result is information on the size of the dust, the number of dusts, and the position where the dust is present.   6. The optical device with a dustproof function according to claim 4, wherein the operation parameter to be changed is an operation time or an operation frequency of the dust removing unit.   The optical device with a dustproof function according to any one of claims 1 to 6, wherein the dust removing unit is a vibrating unit that vibrates the optical element at a predetermined frequency. The dust removing unit is a vibrating unit that vibrates the optical element at a predetermined frequency.
6. The optical device with a dustproof function according to claim 4, wherein the operation parameter to be changed is an excitation time, an excitation frequency, or an applied voltage for driving of the excitation unit. The dust removing unit is a vibrating unit that vibrates the optical element at a predetermined frequency.
6. The optical device with a dustproof function according to claim 4, wherein the operation parameter to be changed is an excitation mode of the excitation means.   10. The dust presence / absence determining unit determines the presence / absence of a foreign substance by comparing the luminance of pixel data output from the photoelectric conversion element. Optical device with dustproof function.   The optical device with a dustproof function according to claim 10, wherein the pixel data is pixel data output from the photoelectric conversion element when an optical image of a subject having a substantially uniform luminance distribution is received.   The dust presence / absence determining means determines that foreign matter is present when the difference in average luminance for each predetermined pixel number region is greater than or equal to a predetermined value for the pixel data output from the photoelectric conversion element. The optical device with a dustproof function according to claim 10 or 11.   In the pixel data output from the photoelectric conversion element, the dust presence / absence determining means determines that a foreign object is present when a difference in luminance between a predetermined pixel region and a peripheral region located around the pixel region is equal to or greater than a predetermined value. The optical device with a dustproof function according to any one of claims 10 to 12, characterized in that it is present.

Images