JP2007047199A - Finder device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a finder device capable of removing dust infiltrating from a mount aperture, in a lens interchangeable type camera. <P>SOLUTION: A focusing screen 61 is arranged in a finder unit body 70 in the observation optical path of a single-lens reflex camera. A dust-proof filter B 60 is arranged on the incident surface side of the screen mat 61, and space formed by the dust-proof filter B 60 and the focusing screen 61 is sealed by a packing 71. A piezoelectric element B 72, for vibrating the dust-proof filter B 60, is arranged at the periphery part of the dust-proof filter B 60. Then, the dust-proof filter B 60 is pressed against the finder unit body 70 by filter fixing plates 74 and 74. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a finder device, and more particularly, to an optical device that removes dust adhering to an optical element that is installed in an optical path of a generated optical device and through which a light beam that forms an image passes.

  2. Description of the Related Art Conventionally, a camera that subjects a subject image formed by a photographing optical system such as a photographing lens to photoelectric conversion by an image sensor and displays it on an image display device such as a liquid crystal monitor based on an image signal obtained thereby is generally used. Known to.

In the case of an interchangeable lens camera, dust may enter the mirror box and adhere to the focusing screen when the lens is replaced. When dust adhered to the focusing screen, the viewfinder image was unsightly. In order to prevent this, a technique for removing dust adhering to the finder optical system is disclosed in Patent Document 1 below.
Utility Model Registration No. 2605249

  However, although the apparatus described in Patent Document 1 describes the removal of dust attached to the finder optical system, it does not describe the point of removing the dust that has entered through the mount opening where the interchangeable lens is mounted. It was not.

  Accordingly, an object of the present invention is to provide a finder device capable of removing dust that has entered through a mount opening in an interchangeable lens camera.

  That is, the invention described in claim 1 includes a screen mat disposed in the observation optical path, a holding member for holding the screen mat, a dustproof filter disposed on the incident surface side of the screen mat, and the dustproof filter. A sealing member that seals a space formed by the screen mat; and a pressing member that presses the dust-proof filter against the holding member, and vibrates the dust-proof filter at a peripheral portion of the dust-proof filter. The vibration member for this is arrange | positioned, It is characterized by the above-mentioned.

  According to a second aspect of the present invention, in the first aspect of the present invention, the excitation member includes a piezoelectric element, and the dust filter is vibrated by an expansion / contraction operation of the piezoelectric element.

  According to a third aspect of the present invention, there is provided a screen mat that is disposed in the observation optical path and forms a subject image, a holding member that holds the screen mat, and a dustproof filter that is disposed on the incident surface side of the screen mat. And a vibrating means for vibrating the dust filter at a predetermined frequency.

  According to a fourth aspect of the present invention, in the third aspect of the present invention, the exciting means is disposed at a peripheral edge of the dustproof filter.

  According to a fifth aspect of the present invention, in the third aspect of the present invention, the excitation means includes a piezoelectric element, and the dustproof filter is vibrated by an expansion / contraction operation of the piezoelectric element.

  The invention according to claim 6 is the invention according to claim 3, further comprising a sealing member that seals a space formed by the dustproof filter and the screen mat. .

  According to a seventh aspect of the present invention, in the third aspect of the present invention, the excitation means vibrates the dust filter at a resonance frequency.

  The invention described in claim 8 is the invention described in claim 7, further comprising a drive circuit for driving the excitation means.

  The invention according to claim 9 is the invention according to claim 8, wherein the drive circuit supplies a periodic drive signal to the excitation means, and the dustproof filter has the resonance frequency. The frequency of the drive signal is set so as to vibrate in the vicinity.

  ADVANTAGE OF THE INVENTION According to this invention, the finder apparatus which can remove the dust which penetrate | invaded from the mount opening in an interchangeable lens camera can be provided.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an embodiment of the present invention, and is an external perspective view showing a configuration of a single-lens reflex digital camera to which a finder device of the present invention is applied.

In FIG. 1, this single-lens reflex digital camera (hereinafter abbreviated as “camera”) 1 is mainly composed of a lens barrel 10 as an interchangeable lens and a camera body 30. A desired lens barrel 10 is detachably set with respect to the front surface.
On the upper surface of the camera body 30, a release button 31, a mode dial 32, a power switch lever 33, a control dial 34, and the like are provided.

  The release button 31 is a button for executing a shooting preparation operation and an exposure operation. The release button 31 is composed of a two-stage switch of a first release switch and a second release switch. When the release button 31 is pressed halfway, the first release switch is turned on to perform photometric processing or Shooting preparation operations such as distance measurement processing are executed. Further, when the release button 31 is fully pressed, the second release switch is turned on and the exposure operation is executed.

  The mode dial 32 is an operation member for setting a shooting mode at the time of shooting. When the mode dial 32 is rotated in a predetermined direction, a shooting mode at the time of shooting is set. The present embodiment also has a function of switching an image displayed on a liquid crystal monitor (to be described later) between a viewfinder view and a live view. The power switch lever 33 is an operation member for turning on / off the power of the camera 1. By turning the power switch lever 33, the main power source of the camera 1 is switched on / off.

  The control dial 34 is a member for setting shooting information. By operating the control dial 34, various settings are performed during shooting.

  On the back surface of the body unit 30, a liquid crystal monitor 36 for displaying a photographed image, a menu, and the like, a playback button 37, a menu button 38, a cross key 40, an OK button 41, and an eyepiece optical system finder 43 are provided. Etc. are arranged.

  The playback button 37 is a button for switching the operation mode of the camera 1 to a playback mode in which an image can be played back from a JPEG file recorded on a flash memory 84 or a recording medium 85 described later. The menu button 38 is a button for displaying a menu screen on the liquid crystal monitor 36. This menu screen is composed of menu items having a plurality of hierarchical structures. The user can select a desired menu item with the cross key 40 and can determine an item selected with the OK button 41.

  FIG. 2 is a perspective view showing the configuration of the finder optical system of the camera in one embodiment of the present invention.

  The viewfinder optical system 50 includes a plurality of mirrors for guiding the light beam from the subject that has passed through the photographing lens 11 in the lens barrel to the eyepiece lens 64 constituting the viewfinder 43, that is, the first reflection mirror 51 and the second reflection mirror 51. A reflection mirror 52, a third reflection mirror 53, a fourth reflection mirror 54, an eyepiece lens 57, a dustproof filter B60 as a second filter, and a focusing screen (screen mat) 61 are configured.

  The first reflecting mirror 51 is an optical path dividing means, and is configured to be rotatable about the shaft 51a in the direction of the arrow A in the figure. A part of the first reflecting mirror 51 is a half mirror for an AF sensor unit 83 described later. It is configured. As shown in the figure, the first reflecting mirror 51 observes the light beam incident from the photographing lens 11 in the direction of the second reflecting mirror 52, which is an angle of about 90 ° with respect to the optical axis of the photographing lens 11, as shown in the figure. Reflected rightward when viewed from the lens barrel 10 side of the camera body 30. At the time of imaging, the light beam is retracted from the imaging optical path and operates so that the light flux from the subject is guided to an imaging element (not shown) disposed behind the first reflection mirror 51.

  Further, the light beam transmitted through the half mirror portion of the first reflecting mirror 51 during observation is reflected below the camera body 30 by the AF movable mirror 57 and guided to an AF sensor unit 83 described later. The AF movable mirror 57 is also provided so as to be able to advance and retreat in the photographing optical path in conjunction with the first reflecting mirror. That is, it is arranged in the photographing optical path during observation, but is retracted out of the photographing optical path during photographing. In this case, it is retracted below the camera body 20 and positioned behind the AF movable mirror 57 on the photographing optical axis. A light beam from a subject (not shown) is guided to a dustproof filter A58, which is a first filter.

  The light beam reflected by the reflecting surface of the first reflecting mirror 51 enters the second reflecting mirror 52 through the dustproof filter B60 and the focusing screen 61. The second reflection mirror 52 is disposed on the reflection optical axis from the first reflection mirror 51, and the reflection surface is inclined at a predetermined angle with respect to the reflection optical axis of the first reflection mirror 51. Yes. The reflected light beam from the first reflecting mirror 51 incident on the second reflecting mirror 52 is reflected toward the angle of about 90 ° with respect to the reflected optical axis from the first reflecting mirror 51, that is, upward of the camera body 30. Is done.

  The light beam reflected by the reflecting surface of the second reflecting mirror 52 is on the reflecting optical axis of the reflecting surface of the second reflecting mirror 52, and the reflecting surface is predetermined with respect to the reflecting optical axis of the second reflecting surface. It is incident on the third reflecting mirror 53 that is inclined at an angle of. The reflected light beam from the second reflecting mirror 52 incident on the third reflecting mirror 53 is approximately 90 ° with respect to the reflected optical axis from the reflecting surface of the second reflecting mirror 52 at the reflecting surface of the third reflecting mirror 53. And is reflected in a direction opposite to the reflection direction by the reflection surface of the first reflection mirror 51. That is, the reflected light beam from the reflecting surface of the second reflecting mirror 52 is reflected by the reflecting surface of the third reflecting mirror 53 toward the left direction of the camera body 30. In other words, the light beam reflected by the reflecting surface of the first reflecting mirror 51 is guided by the second and third reflecting mirrors 52 and 53 so that the reflected optical axis of the reflecting surface of the third reflecting mirror 53 is The first reflection mirror 51 is directed to the fourth reflection mirror 54 substantially parallel to the reflection optical axis of the reflection surface.

  The light beam reflected by the reflecting surface of the third reflecting mirror 53 is on the reflecting optical axis of the reflecting surface of the third reflecting mirror 53, and the reflecting surface is the reflected light of the reflecting surface of the third reflecting mirror 53. The light is incident on a fourth reflecting mirror 54 that is disposed at a predetermined angle with respect to the axis. Then, the reflected light beam from the third reflection mirror 53 incident on the fourth reflection mirror 54 is approximately 90 ° with respect to the reflection optical axis from the third reflection mirror 53 on the reflection surface of the fourth reflection mirror 54. Reflected at an angle of. That is, the reflected light beam from the reflection surface of the third reflection mirror 53 is incident on the eyepiece 64 disposed on the reflection optical axis of the reflection surface of the fourth reflection mirror 54.

  The focusing screen 61 has a diffusing surface for diffusing the light beam incident on the finder optical system 50 described above as an optical image, and is on the image pickup surface of a recording image pickup device 80 to be described later. Are arranged at optically equivalent positions.

  The second reflection mirror 52 and the fourth reflection mirror 54 are half mirrors. A photometric sensor 62 for measuring the brightness of the subject is disposed on the back side of the reflecting surface of the second reflecting mirror 52. On the other hand, an imaging lens 67 and a through image display image sensor 68 are disposed on the back surface side of the reflection surface of the fourth reflection mirror 54. This through-image display image pickup device 68 is for forming an image on the focusing screen 61 through an image forming lens 67. Therefore, although the image formed on the through-image display imaging element 68 is inverted, it is the same as the image seen by the photographer's eyes 65.

  In this way, the subject luminous flux from the photographing lens 11 is inverted by the first to fourth reflection mirrors 51 to 54 described above so that the image becomes an erect image and guided to the eyepiece lens 57. As a result, the subject image formed on the focusing screen 61 by the photographer's eye 65 can be observed through the eyepiece 64 (finder 43).

  In the present embodiment, the first reflecting mirror 51, the second reflecting mirror 52, the third reflecting mirror 53, and the fourth reflecting mirror 54 are arranged so as to reflect at an angle of about 90 ° with respect to the incident light beam. However, it is not limited to this.

  FIG. 3A shows a mounting structure of a finder unit main body 70 as a holding member that integrally accommodates the second to fourth reflecting mirrors 52 to 54 and the eyepiece 64, a dustproof filter B60, and a focusing screen 61. It is the shown perspective view. FIG. 3B is a cross-sectional view showing a mounting structure portion of the dustproof filter B60 and the focusing screen 61.

  The second reflection mirror 52, the third reflection mirror 53, the fourth reflection mirror 54, and the eyepiece lens 64 are integrally configured as a finder unit main body 70. A focusing screen 61 is fixed to the incident light side of the finder unit main body 70 by bonding. An annular packing 71 as a sealing member is disposed around the focusing screen 61, and an annular piezoelectric element B72 and a dustproof filter B60 are disposed so as to be pressed against the packing 71.

  The piezoelectric element B72, which is the second vibrating means (vibrating member), is fixed to the dustproof filter B60 by adhesion, and is connected to a dustproof filter driving circuit described later via a flexible substrate 73. The piezoelectric element B72 is attached to the peripheral edge of the dustproof filter B60, and removes dust attached to the surface of the dustproof filter B60 by vibrating the dustproof filter B60 at a predetermined frequency. Further, the filter fixing plate 74 which is a pressing member is fitted into an insertion hole provided at a predetermined position of the finder unit main body 70, so that the dustproof filter B 60 and the piezoelectric element B 61 press the packing 71. Thereby, the incident surface side of the focusing screen 61 is sealed so that dust does not enter.

  An adhesive sheet 75 for adsorbing dust removed by vibration of the dustproof filter B60 (details will be described later) is provided around the focusing screen 61 in the finder unit main body 70. Moreover, although this adhesive sheet 75 is shown only in one place in Fig.3 (a), it is needless to say that it is not restricted to this and multiple may be provided.

  FIG. 4 is a block diagram showing the system configuration of the camera according to one embodiment of the present invention.

  In FIG. 4, the lens barrel 10 can be detachably mounted via a lens mount (not shown) provided on the front surface of the camera body 30. The lens barrel 10 includes a photographic lens 11, a diaphragm 12, a lens driving mechanism 13, a diaphragm driving mechanism 14, and a lens control microcomputer (hereinafter abbreviated as Lμcom) 15. .

  The photographing lens 11 is driven in the optical axis direction by a DC motor (not shown) existing in the lens driving mechanism 13. The diaphragm 12 is driven by a stepping motor (not shown) existing in the diaphragm driving mechanism 14. The Lμcom 15 drives and controls each part in the lens barrel 10 such as the lens driving mechanism 13 and the aperture driving mechanism 14. The Lμcom 15 is electrically connected to a later-described body control microcomputer 80 via the communication connector 20 and controlled according to a command from the body control microcomputer 95.

  On the other hand, the camera body 30 is configured as follows.

  A light beam from a subject (not shown) that is incident through the photographing lens 11 and the diaphragm 12 in the lens barrel 10 is reflected by a first reflecting mirror 51 that is a movable mirror, and then a focusing screen 56 and the first reflecting mirror 51. At the same time, it reaches the eyepiece lens 64 through second to fourth reflecting mirrors 52 to 54 (see FIG. 2) constituting the finder optical system 50. In addition, a part of the subject luminous flux that has passed through the half mirror portion of the first reflecting mirror 51 is reflected by the AF movable mirror 57 that operates independently of the first reflecting mirror 51 to perform automatic ranging. To the AF sensor unit 83. In FIG. 4, the first reflecting mirror 51 is shown separately, but the finder optical system 50 is configured together with the second to fourth reflecting mirrors and the like.

  Behind the first reflecting mirror 51 on the optical axis is a focal plane shutter 78 and a photoelectric conversion element of an imaging optical system for photoelectrically converting a subject image that has passed through the optical system, and is composed of a CCD or the like. A recording image pickup device 80 is provided. That is, when the first reflecting mirror 51 is retracted from the imaging optical path, the light flux that has passed through the imaging lens 11 and the aperture 12 is imaged on the imaging surface of the recording imaging element 80.

  A dustproof filter A58 as an optical element is disposed between the shutter 78 and the recording image pickup device 80. The piezoelectric element A79, which is the first vibrating means (vibrating member), is fixed to the dustproof filter A58 by adhesion, and is attached to the periphery of the dustproof filter A58. The dust attached to the surface of the dust-proof filter A58 is removed by vibrating the dust-proof filter A58 at a predetermined frequency.

  The through image display image sensor 68 and the recording image sensor 80 are connected to an image processing controller 92 for performing image processing via an interface circuit 91. The image processing controller 92 is connected to the above-described liquid crystal monitor 36, the SDRAM 96, the FlashMemory 97, the recording medium 98, and the like provided as storage areas. These are configured to provide an electronic recording display function together with an electronic imaging function.

  The recording medium 98 is an external recording medium such as various memory cards and an external hard disk drive (HDD) that can be attached to and detached from the camera body 30 via a camera interface (not shown).

  The image processing controller 92 includes a photometry circuit 88 including a photometry sensor 62, an AF sensor drive circuit 84, a mirror drive mechanism 85, a shutter charge mechanism 86, a shutter control circuit 87, and drive means (drive) described in detail later. A dust-proof filter driving circuit 90 as a circuit), a temperature measuring circuit 100, and a nonvolatile memory (EEPROM) 101, and a body control microcomputer (hereinafter abbreviated as Bμcom) for controlling each part in the camera body 30. ) 95.

  The Bμcom 95 is further connected with an operation display LCD 102 for notifying the photographer of the operation state of the camera by display output, a camera operation switch (SW) 103, and a battery 106 via a power circuit 105. ing.

  The Bμcom 95 and the Lμcom 15 are electrically connected to each other via the communication connector 20 when the lens barrel 10 is mounted. As a digital camera, Lμcom 15 operates in cooperation with Bμcom 95 in a dependent manner.

  The AF sensor driving circuit 84 is a circuit for driving and controlling the AF sensor unit 83, and the mirror driving mechanism 85 is a mechanism for driving and controlling the first reflecting mirror 51. The shutter charge mechanism 86 charges a spring that drives a front curtain and a rear curtain (not shown) constituting the shutter 78. The shutter control circuit 87 controls the movement of the front and rear curtains of the shutter 78, and exchanges a signal for controlling the opening / closing operation of the shutter and a signal synchronized with the strobe with the Bμcom 95. The photometric circuit 88 is a circuit that performs photometric processing based on the electrical signal of the photometric sensor 62 in the vicinity of the second reflecting mirror 52.

  The temperature measurement circuit 100 is provided in the vicinity of the dust-proof filter A58 in order to measure the temperature around the recording image sensor 80. Normally, temperature affects the elastic modulus of glass materials and is one of the factors that change its natural frequency. Therefore, the temperature must be measured during operation and changes in its natural frequency must be taken into account. I must. It is better to estimate the natural frequency at that time by measuring the temperature change of the dust-proof filter A58 provided to protect the front surface of the recording image sensor 80 where the temperature rises rapidly during operation. Therefore, in this example, a sensor (not shown) connected to the temperature measurement circuit 100 is provided to measure the ambient temperature of the recording image sensor 80. The temperature measurement point of the sensor is preferably set in the vicinity of the vibration surface of the dust filter A58.

  The nonvolatile memory 101 is a storage unit that stores predetermined control parameters necessary for camera control as a storage area other than the above-described SDRAM 96, FlashMemory 97, and recording medium 98, and is provided so as to be accessible from Bμcom 95.

  The operation display LCD 102 is for notifying the user of the operation state of the camera by display output. The camera operation switch 103 serves as switching means, for example, a release switch for instructing execution of a shooting operation and switching the first reflecting mirror 51 in and out of the shooting optical path as will be described later, a mode change switch for switching between a shooting mode and an image display mode, and It is composed of a switch group including operation buttons necessary for operating the camera, such as a power switch. Further, the power supply circuit 105 is provided for converting the voltage of the battery 106 as a power supply into a voltage required for each circuit unit of the camera system and supplying it.

  Next, based on the circuit diagram of the dustproof filter driving circuit 90 shown in FIG. 5 and the time chart shown in FIG. 6, the driving and operation of the dustproof filters A58 and B60 of the camera in this embodiment will be described. .

  The dust filter driving circuit 90 illustrated here has a circuit configuration as shown in FIG. 5, and in each part, signals having waveforms (Sig1 to Sig4) shown in the time chart of FIG. 6 are generated. The following control is performed based on the signal.

  As shown in FIG. 5, the dustproof filter driving circuit 90 includes an N-ary counter 111, a ½ divider circuit 112, an inverter 113, a plurality of MOS transistors (Q1, Q2, Q3) 114a, 114b, 114c, and a transformer 115. And a resistor (R1) 116.

  The transformer 115 generates a signal (Sig4) with a predetermined period on the secondary side of the transformer 115 by the on / off switching operation of the transistor (Q2) 114b and the transistor (Q3) 114c connected to the primary side. It is configured as follows. Further, the piezoelectric element A79 and the piezoelectric element B72 connected in parallel are driven based on the signal of this predetermined period, and the dustproof filter A58 and the dustproof filter B60 are caused to resonate.

  The Bμcom 95 controls the dustproof filter driving circuit 90 through the two IO ports P_PwCont and IO port D_NCnt provided as control ports and the clock generator 110 existing inside the Bμcom 95 as follows.

  The clock generator 110 outputs a pulse signal (basic clock signal) to the N-ary counter 111 at a frequency sufficiently faster than the signal frequency applied to the piezoelectric element A 79 and the piezoelectric element B 72. This output signal is a signal Sig1 having a waveform represented by the time chart in FIG. This basic clock signal is input to the N-ary counter 111.

  The N-ary counter 111 counts the 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 the 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 divider circuit 112. 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 (Q2) 114b to which this signal is input is turned on.

  On the other hand, this pulse signal is applied to the transistor (Q3) 114c via the inverter 113. Therefore, in the low state of the pulse signal, the transistor (Q3) 114c to which this signal is input is turned on. When the transistor (Q2) 114b and the transistor (Q3) 114c connected to the primary side of the transformer 115 are alternately turned on, a signal having a cycle such as the signal Sig4 represented by the time chart in FIG. 6 is generated on the secondary side. To do.

  The winding ratio of the transformer 115 is determined from the output voltage of the unit of the power supply circuit 105 and the voltage necessary for driving the piezoelectric element A79 and the piezoelectric element B72. The resistor (R1) 116 is provided to restrict an excessive current from flowing through the transformer 115.

  When driving the piezoelectric element A 79 and the piezoelectric element B 72, the transistor (Q 1) 114 a is in an on state, and a voltage must be applied from the unit of the power supply circuit 105 to the center tap of the transformer 115. In the figure, on / off control of the transistor (Q1) 114a is performed via P_PwCont of the IO port. The set value “N” of the N-ary counter 111 can be set from the IO port D_NCnt. Therefore, the Bμcom 95 can arbitrarily change the drive frequency of the piezoelectric element A79 and the piezoelectric element B72 by appropriately controlling the set value “N”.

At this time, the frequency can be calculated by the following equation (1).
N: Set value to counter
fpls: frequency of the output pulse of the clock generator,
fdrv: the frequency of the signal applied to the electromechanical transducer,
fdrv = fpls / 2N (1)
The calculation based on this equation is performed by a CPU of Bμcom95.

  Next, the basic photographing operation of the camera according to the present embodiment will be described with reference to the flowcharts of FIGS.

  When a battery (not shown) is inserted into the camera body 30, this routine is started. First, in step S1, the state of the power switch (SW) by the power switch lever 33 is determined. If the power switch is not turned on, the process proceeds to step S2 to enter a sleep state (low current consumption state), which is a state waiting for operation. If any operation of the camera 1 is performed from this sleep state, and if the power switch is turned on in the above step S2, the process proceeds to step S3, for example, resetting the lens or electrically initializing the electric circuit. The initialization operation of the camera is performed.

  Next, in step S4, a subroutine “dust removal operation” is executed. The details of this subroutine “dust removal operation” will be described later. When the mode dial 32 is checked in step S5, a determination is made to shift to the following mode. That is, first, in step S6, it is determined whether or not the through image mode is set. If the through image mode is selected, the process proceeds to step S7, where the through image mode is set. If the current mode is other than the through image mode in step S6, the process proceeds to step S8 to determine whether the normal mode is set. If the normal mode is selected here, the process proceeds to step S9, where the normal mode is set. In steps S6 and S8, if neither the through image mode nor the normal mode is selected, it is determined that the image capturing mode is not set, and the process proceeds to step S10 to set the image reproduction mode.

  If any of the steps S7, S9, or S10 is set, the process proceeds to step S11 to determine the state of the power switch described above. If the power switch is on, the process proceeds to step S5, and the above-described mode determination and setting processing operations are repeated until the power switch is turned off in step S11. When the power switch is turned off in step S11, the process proceeds to step S2 and enters a sleep state.

  FIG. 8 is a flowchart for explaining the subroutine “dust removal operation” in step S4 in the flowchart of FIG.

  The camera 1 of this embodiment has two different dustproof removal filters A58 and B60, and the resonance frequencies are also different. Therefore, in this subroutine “dust removal operation”, different resonance frequencies are set.

  That is, when the subroutine "dust removal operation" is entered, first, in step S21, a first vibration frequency, for example, a resonance (vibration) frequency for the dustproof filter A58 is set. Next, in step S22, the vibration operation by the piezoelectric element A79 is started at the first frequency set in step S21. The vibration operation started in step S22 is performed until a predetermined time has elapsed in step S23.

  Next, in step S24, a second vibration frequency different from the first vibration frequency described above, for example, a vibration frequency for the dustproof filter B60 is set. In step S25, the vibration operation by the piezoelectric element B72 is started at the second vibration frequency set in step S24. Thereafter, the vibration operation started in step S25 is performed until a predetermined time elapses in step S26. Further, when the vibration processing end process is performed in step S27, the process exits from this subroutine and proceeds to step S5 in the flowchart of FIG.

  In this way, since the two dustproof filters having two different vibration frequencies are vibrated at the respective frequencies, not only the photographing optical system but also the dust in the finder optical system can be removed.

  Next, a modification of this embodiment will be described.

  In the embodiment described above, the vibration frequency is set stepwise for two dustproof filters having two different vibration frequencies, but the present invention is not limited to this. For example, after the vibration operation at the first frequency is performed, the vibration frequency may be changed to perform the vibration operation at the second frequency.

  Hereinafter, with reference to the flowchart of FIG. 9, the modification of one Embodiment of this invention is demonstrated.

  FIG. 9 is a flowchart for explaining a modification of the subroutine “dust removal operation” in step S4 in the flowchart of FIG.

  When the subroutine “dust removal operation” is entered, first, in step S31, a first vibration frequency, for example, a vibration frequency for the dustproof filter A58 is set. Next, in step S32, the vibration operation by the piezoelectric element A79 is started at the first frequency set in step S31. In step S33, a predetermined time, for example, 10 msec. Until the time elapses, the vibration operation started in step S32 is performed.

  Next, in step S34, the first vibration frequency set in step S31 is changed. In this case, the frequency is changed to a frequency higher than the first vibration frequency described above. In step S35, it is determined whether or not a second vibration frequency different from the first vibration frequency, for example, the vibration frequency for the dustproof filter B60 has been reached. If the second vibration frequency input / output has not yet been reached, the process proceeds to step S33, and the above-described processing operations of steps S33 to S35 are repeated until the second vibration frequency is reached.

  When the second vibration frequency is reached in step S35, the vibration operation end process is performed in step S36. Thereafter, the present subroutine is exited and the process proceeds to step S5 in the flowchart of FIG.

  In this way, even if two dust filters having two different vibration frequencies are vibrated by changing the set frequency, not only the photographic optical system but also the finder optical system as in the above-described embodiment. System dust can also be removed.

  In the above-described embodiment, the first and second vibration frequencies are set to predetermined values, but the present invention is not limited to this. For example, sweeping is performed in each vibration frequency band. You may make it let it. In this way, vibration is generated in the vicinity of the set frequency instead of the set frequency, so that the dust removal operation can be performed more quickly than the above-described modification.

  As mentioned above, although embodiment of this invention was described, in the range which does not deviate from the summary of this invention other than embodiment mentioned above, this invention can be variously modified.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external perspective view showing a configuration of a single-lens reflex digital camera to which a finder device of the present invention is applied, showing an embodiment of the present invention. 1 is a perspective view illustrating a configuration of a finder optical system of a camera according to an embodiment of the present invention. (A) is the perspective view which showed the attachment structure of the finder unit main body 70 which accommodates the 2nd thru | or 4th reflective mirrors 52-54, and the eyepiece lens 64 integrally, dustproof filter B60, and the focusing screen 61, (b). It is sectional drawing which showed the attachment structure part of dustproof filter B60 and the focusing screen 61. FIG. It is a block diagram which shows the system configuration | structure of the camera which concerns on one Embodiment of this invention. FIG. 5 is a circuit diagram showing a configuration of a dustproof filter driving circuit 90 in FIG. 4. It is a time chart showing the waveform signal concerning the drive of a dustproof filter, and its operation. 6 is a flowchart for explaining basic photographing operation of a camera according to an embodiment of the present invention. It is a flowchart explaining the subroutine “dust removal operation” of step S4 in the flowchart of FIG. It is a flowchart explaining the modification of the subroutine "dust removal operation | movement" of step S4 in the flowchart of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Lens barrel, 11 ... Shooting lens, 12 ... Diaphragm, 13 ... Lens drive mechanism, 14 ... Diaphragm drive mechanism, 15 ... Microcomputer for lens control (L [mu] com), 20 ... Communication connector, 30 ... Camera body, 31 ... Release button, 32 ... mode dial, 33 ... power switch lever, 34 ... control dial, 36 ... liquid crystal monitor, 43 ... finder, 50 ... finder optical system, 51 ... first reflecting mirror, 52 ... second reflecting mirror, 53 ... Third reflective mirror, 54 ... Fourth reflective mirror, 57 ... AF movable mirror, 58 ... Dust filter A, 60 ... Dust filter B, 61 ... Focusing screen, 62 ... Photometric sensor, 64 ... Eyepiece, 68 ... Through image Display image sensor, 70 ... finder unit main body, 72 ... Piezoelectric element B, 78 ... Shutter, 79 ... Piezoelectric Child A, 80 ... Recording image sensor, 83 ... AF sensor unit, 84 ... AF sensor drive circuit, 85 ... Mirror drive mechanism, 86 ... Shutter charge mechanism, 87 ... Shutter control circuit, 91 ... Interface circuit, 92 ... Image processing Controller, 96 ... SDRAM, 97 ... FlashMemory, 98 ... Recording medium, 100 ... Temperature measuring circuit, 101 ... Nonvolatile memory (EEPROM), 102 ... Operation display LCD, 103 ... Camera operation switch (SW), 105 ... Power supply circuit .

Claims (9)

A screen mat placed in the observation optical path;
A holding member for holding the screen mat;
A dust filter disposed on the incident surface side of the screen mat;
A sealing member for sealing a space formed by the dustproof filter and the screen mat;
A pressing member that presses the dustproof filter against the holding member;
Comprising
A finder device, wherein a vibration member for vibrating the dust filter is disposed at a peripheral portion of the dust filter.   The finder apparatus according to claim 1, wherein the vibration member includes a piezoelectric element, and the dust filter is vibrated by an expansion / contraction operation of the piezoelectric element. A screen mat which is arranged in the observation optical path and forms a subject image;
A holding member for holding the screen mat;
A dust filter disposed on the incident surface side of the screen mat;
Vibration means for vibrating the dust filter at a predetermined frequency;
A finder device comprising:   The finder device according to claim 3, wherein the vibration means is disposed at a peripheral edge of the dust filter.   4. The finder apparatus according to claim 3, wherein the vibration means includes a piezoelectric element, and the dustproof filter is vibrated by an expansion / contraction operation of the piezoelectric element.   The finder apparatus according to claim 3, further comprising a sealing member that seals a space formed by the dustproof filter and the screen mat.   4. The finder apparatus according to claim 3, wherein the vibration means vibrates the dust filter at a resonance frequency.   8. The finder apparatus according to claim 7, further comprising a drive circuit that drives the vibration means.   The drive circuit supplies a periodic drive signal to the excitation means, and the frequency of the drive signal is set so that the dustproof filter can vibrate near the resonance frequency. The finder device according to claim 8.

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