JP2007110550A - Imaging apparatus - Google Patents

Abstract

An imaging apparatus is provided that can prevent foreign objects from appearing in a captured image with a low cost and with high probability.
When a half mirror 111 is raised, a charge lever 170 is rotated clockwise. At this time, the charge lever 170 collides with the transmission bar 178 immediately before it stops colliding with the stopper 175 and stops rotating. Due to this collision, the transmission bar moves to the left (in the direction of arrow B) against its rightward biasing force and collides with the low-pass filter 11a. Due to this collision, the low-pass filter 11a vibrates, and the vibration removes foreign matters such as dust adhering to the surface of the low-pass filter 11a exposed to the outside. By removing the foreign matter, the foreign matter is prevented from appearing in the photographed image.
[Selection] Figure 5

Description

  The present invention relates to an imaging apparatus such as a digital camera, and more particularly to an imaging apparatus suitable for removing foreign matters such as dust attached to a light transmission member such as a low-pass filter.

  In a lens interchangeable digital single-lens reflex camera, foreign matter such as dust may enter from the outside during lens replacement. If the foreign matter adheres to a light transmission member on the optical path that reaches the photoelectric conversion surface of the solid-state image sensor, that is, a cover glass or an optical filter that protects the solid-state image sensor, the foreign matter or the shadow of the foreign matter is It will appear in the captured image. In addition, the foreign matter may not only enter from the outside, but may also become a foreign matter due to generation of fine wear powder such as resin as its structural member in accordance with the operation of the shutter and mirror inside the camera.

  If such foreign matter enters between the cover glass that protects the solid-state imaging device and the optical filter disposed on the front side of the cover glass, a camera is used to remove the foreign matter. It was necessary to disassemble. For this reason, a method of adopting a sealed structure has been adopted so that foreign matter does not enter between the cover glass of the solid-state imaging device and the optical filter.

  However, even with a sealed structure, when a foreign object adheres to the surface exposed to the outside of the optical filter (hereinafter referred to as an exposed surface), the foreign object or the shadow of the foreign object may appear in the captured image. .

  Therefore, a method of cleaning the exposed surface of an optical member such as a low-pass filter with a wiper has been devised in order to remove foreign matters attached to the exposed surface (see Patent Document 1). In this method, the foreign matter adhering to the exposed surface of the optical member can be removed without removing the lens and without disassembling the camera.

  However, in the configuration of Patent Document 1, the exposed surface of the optical member is rubbed with a wiper. For this reason, when the foreign material is hard, for example, metal powder, the exposed surface of the optical member may be scratched by the foreign material. If this scratch is located on the optical path leading to the photoelectric conversion surface of the solid-state image sensor, the shadow of the scratch appears in the captured image.

Further, a technique has been devised that removes foreign matter adhering to the exposed surface of the dust-proof member by vibrating a dust-proof member that seals or protects the photoelectric conversion surface side of the solid-state imaging device (see Patent Document 2).
JP 2001-298640 A JP 2003-338967 A

  However, the technique disclosed in Patent Document 2 requires a mechanical structure for vibrating the dust-proof member, an electric component for driving the structure, and the like, which increases costs.

  The present invention has been made in view of such problems of the prior art. That is, an object of the present invention is to provide an imaging apparatus that can prevent foreign objects from appearing in a photographed image with a low-cost configuration and with a high probability.

  In order to achieve the above object, the present invention operates before an image is picked up by an image pickup means for converting an optical image of a subject into an electrical signal, a light transmitting member disposed in front of the image pickup means, and the image pickup means. An imaging apparatus including an imaging preparation unit that includes a transmission member that transmits kinetic energy used when the imaging preparation unit is operated to the light transmission member.

  According to the present invention, it is only necessary to provide a transmission member that transmits the existing kinetic energy used when operating the imaging preparation means to the light transmission member. That is, by supplying the existing kinetic energy to the light transmission member via the transmission member, the light transmission member can be vibrated. Therefore, almost all foreign matters such as dust attached to the light transmitting member can be removed with the vibration of the light transmitting member. In other words, it is possible to provide an imaging apparatus that can prevent foreign objects from being reflected in a captured image captured by the imaging unit with a low cost and with a high probability.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view showing a schematic configuration of an imaging apparatus according to first to fourth embodiments of the present invention. The imaging apparatus is configured as a lens interchangeable digital single lens reflex camera (hereinafter referred to as D-SLR). The D-SLR 100 is a single-plate digital color camera using a solid-state imaging device such as a CCD or CMOS sensor. The D-SLR 100 can capture a moving image or a still image by driving and controlling the solid-state imaging device continuously or once. The solid-state imaging device is configured as an area sensor in which photoelectric conversion elements (pixels) are two-dimensionally arranged.

  FIG. 2 is a cross-sectional view illustrating a schematic configuration of the imaging unit 10 and the focal plane shutter 50 of the D-SLR 100. FIG. 3 is a block diagram illustrating an electrical configuration of the imaging apparatus. 4 and 5 are diagrams for explaining a mechanical driving state of the half mirror 111 of the D-SLR 100 according to the first embodiment. FIG. 6 is a flowchart showing a foreign substance removal process associated with driving of the half mirror 111. 2, 3, and 6 are drawings common to the first to fourth embodiments.

  As shown in FIGS. 1 and 3, the D-SLR 100 includes a detachable photographic lens device 101. The photographic lens device 101 includes a stop 102 and an imaging optical system 103, as shown in FIG. In addition, 103a shown in FIG. 1 is a lens disposed at a position closest to the half mirror 111 among a plurality of lenses constituting the imaging optical system 103.

  The photographic lens device 101 can be mechanically attached to the D-SLR 100 via the mount mechanism 126. In this mounted state, the photographic lens device 101 is also electrically connected to the D-SLR 100 via the contacts 101a and 100a shown in FIG. By changing to a photographic lens with a different focal length, it is possible to obtain photographic images with various angles of view. The taking lens device 101 has a drive mechanism (not shown) for performing a focusing operation, a zooming operation, and the like.

  A light transmission member 11 is disposed in the optical path L1 from the imaging optical system 103 to the photoelectric conversion surface of the solid-state imaging device 15 of the imaging unit 10. Examples of the light transmitting member 11 include a low-pass filter that cuts a spatial frequency component higher than necessary in an optical image, an infrared cut filter that cuts infrared rays, and the like.

  The signal read from the solid-state imaging device 15 is subjected to predetermined processing as will be described later, and then displayed on the display 107 as photographed image data. The display 107 is attached to the back surface of the D-SLR 100 so that the user can directly check the captured image. In the present embodiment, a MOS image sensor is used as the image sensor of the solid-state imaging device 15, but a CCD image sensor can also be used.

  The half mirror 111 reflects a part of the light beam from the imaging optical system 103 and transmits the remaining light beam. As will be described later, the half mirror 111 is rotatable to a position 111a in FIG.

  A focusing screen 105 is provided above the rotation position 111 a of the half mirror 111. The arrangement position of the focusing screen 105 is a planned imaging plane of a subject image formed by the imaging optical system 103. The user can visually recognize the subject image formed on the focusing screen 105 through the pentaprism 112 and the finder lenses 109a, 109b, and 109c. An eyepiece shutter 163 is provided between the viewfinder lenses 109b and 109c. The eyepiece shutter 163 is closed during, for example, self-timer shooting. As a result, it is possible to prevent reverse incident light from the finder lenses 109a, 109b, and 109c from entering the solid-state imaging device 15 and becoming a ghost image.

  A movable sub mirror 122 is provided behind the half mirror 111 (on the image plane side). The sub mirror 122 reflects the light beam on the optical path L 1 out of the light beam transmitted through the half mirror 111, that is, the light beam on the optical path reaching the photoelectric conversion surface of the imaging device 15, and guides it to the focus detection unit 121. The sub mirror 122 rotates around a rotation axis provided on a holding member of the half mirror 111 (not shown). That is, the sub mirror 122 rotates in conjunction with the rotation of the half mirror 111 (see reference numeral 112a in FIG. 1). The focus detection unit 121 receives the light beam from the sub-mirror 122 and performs focus detection by the phase difference detection method.

  The material of the half mirror 111 is a lightweight transparent resin for high-speed rotation. Further, a fine pyramid-shaped periodic structure having a pitch smaller than the wavelength of visible light may be formed on the surface of the half mirror 111 with a resin. In this case, the periodic structure formed on the surface of the half mirror 111 acts as a so-called photonic crystal, reducing the surface reflection of light due to the difference in refractive index between air and resin, and improving the light utilization efficiency. It becomes possible.

  In the following description, the optical path passing through the positions of reference numerals 111a and 122a in FIG. 1 is referred to as a finder optical path. In addition, the optical path L1 from the imaging optical system 103 to the solid-state imaging device 15 of the imaging unit 10 is referred to as a photographing optical path.

  Next, the focus detection unit 121 will be described. The focus detection unit 121 includes a condenser lens 164, a reflection mirror 165, a re-imaging lens 166, and a focus detection sensor 167.

  A light beam (subject image) incident from the imaging optical system 103 and reflected by the sub mirror 122 is imaged on the focus detection sensor 167 via the condenser lens 164, the reflection mirror 165, and the re-imaging lens 166. The

  The focus detection sensor 167 has at least two pixel columns. Between the output signal waveforms of these two pixel columns, a relatively laterally shifted state is observed according to the imaging state (focused state) of the subject image formed by the imaging optical system 103. The In the so-called front pin state and rear pin state, the shift directions of the output signal waveforms of the two pixel columns are reversed. Therefore, a focus detection unit (not shown) of the focus detection unit 121 detects the shift amount (phase difference) and the shift direction using a technique such as correlation calculation. Then, the focus detection unit outputs the detection information as focus control information.

  On the top of the D-SLR 100, a movable flash light emitting unit 104 is provided. The flash light emitting unit 104 is rotatable between a storage position in the D-SLR 100 and a light emission position protruding from the D-SLR 100. Further, the D-SLR 100 is provided with a main switch 119 for activating the D-SLR 100 and a release button 120. The release button 120 includes a first switch (SW1) and a second switch (SW2) that are turned on in two steps of pressing strokes. When the release button 120 is pressed halfway, the first switch (SW1) is turned on, and a shooting preparation operation (photometry operation, focus adjustment operation, etc.) is started. Further, when the release button 120 is fully pressed, the second switch (SW2) is turned on, and the photographing operation using the solid-state imaging device 15 is started.

  A focal plane shutter 50 and an imaging unit 10 are provided behind the half mirror 122 (image plane side). The configuration of the focal plane shutter 50 and the imaging unit 10 will be described with reference to FIG.

  In FIG. 2, the imaging unit 10 includes a solid-state imaging device 15 and a light transmission member 11. The solid-state imaging device 15b of the solid-state imaging device 15 is covered with a cover glass 15a. The cover glass 15a prevents the solid-state imaging device 15b from being mechanically damaged, and foreign matter such as dust adheres to the solid-state imaging device 15b and the foreign matter or its shadow is reflected in the photographed image. Can be prevented.

  The cover glass 15 a and the light transmission member 11 are sealed with a seal member 16. Accordingly, it is possible to prevent foreign matters such as dust from adhering to the facing surfaces of the cover glass 15a and the light transmitting member 11 and the foreign matter or its shadow from appearing in the photographed image. The solid-state imaging device 15 is electrically connected to a control circuit formed on the substrate 17 through a connection terminal 15c. The substrate 17 is held by the holding plate 18 via the holding member 18a.

  The light transmission member 11 includes a low-pass filter 11a and an infrared cut filter 11b. These low-pass filter 11 a and infrared cut filter 11 b are held by a holding member 12. The low-pass filter 11 a and the infrared cut filter 11 b and the holding member 12 are integrated by a support plate 13. Note that the positional relationship between the low-pass filter 11a and the infrared cut filter 11b in FIG. 2 may be reversed left and right. Further, as the light transmitting member 11, a light transmitting member other than the low pass filter 11a and the infrared cut filter 11b can be used.

  The focal plane shutter 50 has a front curtain 21 and a rear curtain 22. The driving space for the front curtain 21 and the rear curtain 22 is partitioned by an intermediate plate 23. The front curtain 21 has a plurality of shutter blades 21a to 21d. The rear curtain 22 has a plurality of shutter blades in the same manner as the front curtain 21. The rear curtain 22 is pressed in the direction of the intermediate plate 23 by the presser plate 24. The presser plate 24 has an opening 24a at a substantially central portion for imaging.

  The front curtain 21 is pressed in the direction of the intermediate plate 23 by the cover plate 25. The cover plate 25 also has an opening 25a at a substantially central portion for imaging. Furthermore, a stopper rubber 29 for restricting the maximum opening amount of the shutter blades 21a to 21d is attached to the cover plate 25.

  Next, an outline of the electrical configuration of the imaging apparatus will be described based on the block diagram of FIG.

  The photographing lens device 101 has a lens system control unit 141. The lens system control unit 141 performs focusing control by driving and controlling the AF motor 147 to move the focus lens of the imaging optical system 103 on the optical axis. In addition, the lens system control unit 141 drives and controls the diaphragm drive source 143 to change the diaphragm amount of the diaphragm 102. As a result, the amount of light incident on the imaging optical system 103 is adjusted. The lens system control unit 141 performs the drive control as described above based on an instruction from the camera system control unit 135 of the D-SLR 100.

  The lens system control unit 141 can be electrically connected to circuits such as the camera system control unit 135 of the D-SLR 100. This electrical connection is automatically performed when the photographic lens device 101 is attached to the D-SLR 100 via the mount mechanism. This automatic connection is realized by automatically contacting the contact 101a and the contact 100a provided to both of the mounting mechanisms by the above mounting operation.

  The D-SLR 100 performs a photographing operation, image processing, image recording / reproduction processing, and the like with the camera system control unit 135 as a core. The camera system control unit 135 performs these operations and processes in response to various operations by the user detected by the operation detection unit 136, for example, pressing operations of the release button 120. In addition, the camera system control unit 135 displays information such as the operation content and the operation mode corresponding to the operation on the information display unit 142.

  The camera system control unit 135 performs aperture control and focusing control by transmitting information and commands such as the aperture amount and the focus lens drive amount to the lens system control unit 141. In addition, the camera system control unit 135 performs rotation control of the half mirror 111 and the sub mirror 122, opening / closing control of the focal plane shutter 50, and drive control of the solid-state imaging device 15.

  The camera system control unit 135 performs AF (automatic focusing) control using the AF control unit 140. That is, the AF control unit 140 analyzes the signal output from the focus detection sensor 167 based on an instruction from the camera system control unit 135 and detects the focus adjustment state (defocus amount) of the imaging optical system 103. . Then, the AF control unit 140 converts the detected defocus amount into a focus lens drive amount, and transmits the drive amount to the lens system control circuit 141 via the camera system control circuit 135.

  The camera system control unit 135 uses the shutter control unit 145 when performing opening / closing control of the focal plane shutter 50. That is, the shutter control unit 145 appropriately controls the front curtain drive source 35, the charge source 36, and the rear curtain drive source 37 based on an instruction (including the shutter speed) from the camera system control unit 135, so that the focal plane The front curtain 21 and the rear curtain 22 of the shutter 50 are driven to open and close. The front curtain drive source 35 is composed of an electromagnetic actuator, a drive lever, and the like that are configured with known coils and yokes for opening and closing the front curtain 21. The charge source 36 is constituted by a known drive lever, a spring, or the like for closing the opened front curtain 21 again. The rear curtain drive source 37 includes the same components as the front curtain drive source 35.

  In addition, the camera system control unit 135 drives and controls the solid-state imaging device 15 via the imaging device driving unit 137. The solid-state imaging device 15 is driven and controlled by the imaging device driving unit 137 and outputs analog pixel signals of R, G, and B colors. Further, the camera system control unit 135 controls the A / D conversion unit 130, the RGB image processing unit 131, the YC processing unit 132, the recording processing unit 133, and the reproduction processing unit 134 to perform image processing, image recording / reproduction processing. To do.

  The A / D converter 130 converts the analog R, G, B image signals (pixel signals) output from the solid-state imaging device 15 into digital signals. The RGB image processing unit 131 performs image processing such as white balance processing and gamma correction processing on the output signal from the A / D converter 130. The YC processing unit 132 generates a luminance signal Y and color difference signals (RY, BY) based on the image signal output from the RGB image processing unit 131.

  The recording processing unit 133 compresses a luminance signal representing a still image or a moving image and a color difference signal, and records the compressed data as image data on a predetermined recording medium. Note that the recording processing unit 133 has a compression function and an expansion function. In addition, the image data recorded by the recording processing unit 133 can be transmitted to an external computer or the like via the connection terminal 138.

  The reproduction processing unit 134 reads the image data recorded on the recording medium, that is, the luminance signal Y and the color difference signals (RY, BY), and performs matrix conversion processing on the luminance signal Y and the color difference signals. For example, the signal is converted into an RGB signal. The RGB signal converted by the reproduction processing unit 134 is output to the display 107 and displayed.

  Next, the rotation mechanism and the rotation operation of the half mirror 111, which are characteristic points of the present embodiment, will be described with reference to FIGS. In FIGS. 4A, 4B, and 5 and FIGS. 1 and 2 described above, the left and right directions are reversed. 4A and 5 show a state where the half mirror 111 is retracted to the finder optical path, and FIG. 4B shows a state where the half mirror 111 is located in the photographing optical path. .

  4A and 4B, the half mirror 111 is held by a holding member 111a attached to a chassis (not shown) of the D-SLR 100. The holding member 111a is rotatably supported by a rotating shaft 111c attached to the left end portion of the holding member 111a. The holding member 111a is urged in the clockwise direction indicated by the arrow X in FIG. 4A by a torsion spring (not shown) or the like. Further, a locking pin 111b is attached to the right end portion of the holding member 111a. The locking arm 111b of the charge lever 170 is in contact with the locking pin 111b.

  Accordingly, the rotation of the holding member 111a supported by the rotating shaft 111c and urged in the direction of arrow X in FIG. 4A and the half mirror 111 is restricted by the mirror arm portion 170b of the charge lever 170. It will be.

  The charge lever 170 is rotatably supported by a rotating shaft 170a. As shown by the arrow Y in FIG. 4A, the charge lever 170 is urged clockwise by the charge spring 173. One end of the charge spring 173 is locked to the locking portion 171 of the charge lever 170. The other end of the charge spring 173 is locked to a locking portion 174 provided on the chassis of the D-SLR 100 (not shown).

  The stopper 175 is integrally attached to the stud 176. The stopper 175 is made of an elastic body such as rubber. The stopper 175 has a function of regulating the maximum rotation position when the charge lever 170 rotates in the clockwise direction. The stopper 175 also has a function of absorbing an impact force when the half mirror 111 is set in the finder optical path by the rotation of the charge lever 170. The stopper 175 has a function unique to the present embodiment in addition to the above function. This unique function will be described later.

  The transmission bar 178 is newly provided in the present embodiment in order to remove foreign matters such as dust attached to the exposed surface of the light transmission member 11. The transmission bar 178 transmits rotational energy when the charge lever 170 rotates clockwise to the light transmitting member 11. That is, the transmission bar 178 is held by the chassis (not shown) of the D-SLR 100 so as to be movable in the lateral direction of FIGS. 4 (a) and 4 (b). Further, the transmission bar 178 moves in parallel while being guided by a guide member (not shown). Further, the transmission bar 178 is urged in the direction of arrow A shown in FIG. 4A by an urging member (not shown).

  Under such a configuration, the transmission bar 178 collides with the end 170c of the charge lever 170 when the charge lever 170 rotates in the clockwise direction. Due to this collision, the transmission bar 178 moves in the direction opposite to the direction of the arrow A against the urging force in the direction of the arrow A (see arrow B in FIG. 5). The transmission bar 178 collides with the low-pass filter 11a and vibrates the low-pass filter 11a.

  If foreign matter such as dust adheres to the exposed surface of the low-pass filter 11a exposed to the outside of the sealed space due to this vibration, almost all of the foreign matter is removed. That is, there is a possibility that a foreign substance having adhesive force cannot be removed by the vibration. However, in a normal usage form of the imaging apparatus, there is almost no possibility that a foreign substance having adhesive force adheres to the low-pass filter 11a.

  It is also conceivable that fine powder generated by sliding between the shutter blades of the front curtain 21 and the rear winding 22 of the focal plane shutter 50 adheres to the exposed surface of the low-pass filter 11a. However, this fine powder is not sticky and can be easily removed by vibration of the low-pass filter 11a. In the present embodiment, as described above, the foreign matter adhering to the light transmitting member is removed by vibration, so that it is almost impossible to damage the light transmitting member during the removal. .

  Next, the rotation operation of the half mirror 111 accompanying the rotation operation of the charge lever 170 will be described. In the state of FIG. 4A, it is assumed that the charge lever 170 is driven in the direction of arrow A in FIG. 4A by a drive source (for example, a motor) (not shown). In this case, the charge lever 170 starts to rotate counterclockwise around the rotation shaft 170a against the urging force in the clockwise direction by the charge spring 173. As the charge lever 170 rotates, the mirror arm portion 170b of the charge lever 170 also starts to rotate.

  At this time, as described above, the holding member 111a of the half mirror 111 is urged clockwise. Accordingly, the contact state between the locking pin 111b and the mirror arm portion 170b is maintained, but the contact position changes in the direction of the rotation shaft 170a of the charge lever 170 (see FIG. 4B). . As described above, when the contact position between the locking pin 111b and the mirror arm portion 170b changes in the direction of the rotation shaft 170a, the degree of freedom of rotation of the holding member 111a in the clockwise direction gradually increases. As a result, the holding member 111a biased in the clockwise direction rotates together with the half mirror 111 in the clockwise direction.

  Then, when the charge lever 170 rotates to the position shown in FIG. 4B, the locking claw 179 enters the rotation path of the end portion 170 </ b> C of the charge lever 170. Then, the locking claw 179 and the end 170c of the charge lever 170 are in contact with each other. At the timing of the contact state, the rotation drive of the charge lever 170 by the drive source is stopped. In the state of FIG. 4B, the urging force in the direction of arrow Z by the charge spring 173 is regulated by the locking claw 179. Therefore, even if the rotation drive of the charge lever 170 by the drive source is stopped, the half mirror 111 and the charge lever 170 are fixed at the positions shown in FIG.

  When the charge lever 170 rotates counterclockwise, the transmission bar 178 moves to the right due to the above-described urging force. In this case, as shown in FIG. 4B, the amount of movement of the transmission bar 178 in the right direction is such that only a maximum “δ” can be moved from the position of FIG. Is regulated.

  Next, the foreign substance removal processing unique to the present embodiment will be described based on the flowchart of FIG. Note that at the stage of entering this foreign matter removal process, the half mirror 111 is assumed to be in the state of FIG. 4B, that is, in the mirror down state.

  The camera system control unit 135 waits for the first switch SW1 to be turned on by operating the release button 120 (step S100). When the first switch SW1 is turned on, the camera system control unit 135 performs photometry processing and distance measurement processing (step S101). Next, the camera system control unit 135 transmits the driving amount of the focus lens from the AF control circuit 140 to the lens system control unit 141 to execute a focusing operation (step S102). Then, the camera system control unit 135 transmits information related to the exposure value calculated based on the photometric result in step S101 to the lens system control unit 141 to execute an aperture operation (step S103).

  Next, the camera system control unit 135 waits for the second switch SW2 to be turned on by operating the release button 120 (step S104). When the second switch SW2 is turned on, the camera system control circuit 135 raises the half mirror 111 (step S105). When performing this mirror-up control, the camera system control circuit 135 only has to retract the aforementioned locking claw 179 from the rotation path of the end portion 170c of the charge lever 170.

  That is, when the locking claw 179 is retracted downward from the position of FIG. 4B, the charge lever 170 is automatically rotated clockwise by the urging force of the charge spring 173. By this automatic rotation, the contact position between the mirror arm portion 170b of the charge lever 170 and the locking pin 111b of the holding portion 111a resists the urging force in the clockwise direction with respect to the holding portion 111a, and the tip of the mirror arm portion 170b. It will change in the direction. That is, the urging force of the charge spring 173 is set to be larger than the total value of the urging force with respect to the holding portion 111a and the static frictional force between the mirror arm portion 170b and the locking pin 111b.

  Then, when the charge lever 170 collides with the stopper 175, the rotation of the charge lever 170 is automatically stopped. In this rotation stopped state, as shown in FIG. 4A, the locking pin 111b is in contact with the tip of the mirror arm portion 170b. Therefore, the half mirror 111 can stably maintain the position of FIG.

  On the other hand, as described above, the transmission bar 178 has a charge lever of “δ” in the state shown in FIG. 4B before the charge lever 170 rotates in the clockwise direction, compared to the state shown in FIG. It slides in the direction of 170.

  When the charge lever 170 rotates clockwise in the state of FIG. 4B, the charge lever 170 collides with the transmission bar 178 immediately before colliding with the stopper 175, as shown in FIG. That is, the positional relationship between the slide position (regulation position) of the transmission bar 178 and the position where the stopper 175 is disposed is set so that the charge lever 170 collides with the transmission bar 178 immediately before it collides with the stopper 175. Yes.

  When the charge lever 170 rotating in the clockwise direction collides with the transmission bar 178, the rotational energy of the charge lever 170 is transmitted to the transmission bar 178. The transmission bar 178 that has received the rotational energy in this manner slides leftward (in the direction of arrow B) against the rightward biasing force of FIG. 5 and collides with the low-pass filter 11a. That is, the rotational energy of the charge lever 170 is transmitted to the low pass filter 11a via the transmission bar 178. As can be inferred from the above description, the urging force of the charge spring 173 is set larger than the urging force or the like with respect to the transmission bar 178.

  When the transmission bar 178 collides with the low-pass filter 11a, minute vibration is generated in the low-pass filter 11a due to the collision energy. If foreign matter such as dust adheres to the low-pass filter 11a due to this minute vibration, the foreign matter is removed from the low-pass filter 11a.

  As can be inferred from the above description, the charge lever 170 collides with the stopper 175 immediately after colliding with the transmission bar 178, and stops rotating in the clockwise direction. Further, the transmission bar 178 immediately moves away from the low-pass filter 11a after colliding with the low-pass filter 11a by the rightward biasing force. Therefore, the collision energy from the transmission bar 178 is not excessively applied to the low-pass filter 11a, and the low-pass filter 11a is not destroyed. If there is a possibility that a light transmitting member such as the low-pass filter 11a may be destroyed, the transmission bar may be made to collide with a frame (holding member) holding the light transmitting member.

  Further, when the transmission bar 178 collides with the low-pass filter 11a, the low-pass filter 11a may be damaged. However, as shown in FIGS. 4A, 4B, and 5, the position where the transmission bar 178 collides with the low-pass filter 11a is the outer peripheral portion of the low-pass filter 11a, and the imaging region, that is, the solid-state imaging device 15b. It is not a region on the optical path leading to the photoelectric conversion surface. Therefore, even if a scratch occurs in the low-pass filter 11a due to the collision of the transmission bar 178, the scratch does not appear in the captured image.

  The camera system control unit 135 determines whether or not the half mirror 111 has been raised to the position 111a in FIG. 1, that is, the position in FIG. Step S106). This discrimination process is performed based on a mirror position signal from a sensor (not shown). When the half mirror 111 is raised to the position 111a in FIG. 1, the camera system control unit 135 counts for a predetermined time (step S107).

  This counting process has the following significance. That is, the low-pass filter 11a vibrates due to the collision of the transmission bar 178 as described above. Further, the charge lever 170 repeats the bouncing action by the collision with the rubber stopper 175. As the bounce operation is repeated, the half mirror 111 vibrates. Further, depending on the design specifications, the transmission bar 178 repeatedly collides with the low-pass filter 11a as the above-described bounce operation is repeated. Due to this repeated collision, the low-pass filter 11a continues to vibrate.

  Therefore, the camera system control unit 135 counts a predetermined number of seconds in step S107 in order to obtain a blur-free image by performing an actual photographing operation after these vibrations are resolved. Needless to say, when the transmission bar 178 is designed so as to repeatedly collide with the low-pass filter 11a, the function of removing foreign matters attached to the low-pass filter 11a is improved.

  When the count process for a predetermined second is completed, the camera system control unit 135 performs an imaging operation such as driving the focal plane shutter 50 (step S108). Next, the camera system control unit 135 rotates the charge lever 170 counterclockwise by a motor or the like to lower the half mirror 111 (step S109: see FIG. 4B).

  In parallel with the process of step S109 or after the process of step S109 ends, the camera system control unit 135 writes the image data of the subject obtained by the imaging operation in step S108 into the memory (step S110).

  Note that the foreign matter removal operation such as dust described above, that is, the up operation of the half mirror 111 may be performed before the user enters the photographing operation. The timing for performing this foreign substance removal operation may be, for example, when the main switch 119 is turned on or when the photographing lens device 101 is replaced. It is also possible to provide a cleaning mode, that is, a mode in which only the rotation operation of the half mirror 111 described above is performed without recording the subject image by the solid-state imaging device 15.

  As described above, when the foreign substance removing operation is performed before the user enters the photographing operation, the camera system control circuit 135 first raises the half mirror 111 to perform the foreign substance removing operation. Thereafter, the camera system control circuit 135 only needs to lower the half mirror 111 in preparation for a photographing operation, that is, a subject checking operation using a finder. That is, the camera system control circuit 135 does not need to perform control related to other processes and operations such as the photometry / ranging process, aperture operation, and AF operation of FIG.

  According to the above configuration, the existing energy used to drive the half mirror 111 can be used to remove foreign matters such as dust adhering to the exposed surface of the light transmission member 11 simply by adding a few parts such as the transmission bar 178. It becomes possible to use. That is, it is not necessary to provide a separate actuator or the like in order to remove foreign matters, and foreign matters can be removed with an inexpensive configuration.

  In the first embodiment, the cover glass 15 a of the solid-state imaging device 15 and the infrared cut filter 11 b of the light transmission member 11 are in close contact with each other by the seal member 16. Therefore, foreign matter such as dust does not adhere to the cover glass 15a and the infrared cut filter 11b. In other words, in the first embodiment, the light transmitting member is scratched by rubbing the light transmitting member with the wiper, and the scratch is prevented from appearing in the photographed image.

[Second Embodiment]
In the first embodiment, the shape of the transmission bar 178 is a simple bar shape, and there is only one position where the existing energy is transmitted to the light transmission member 11. In the second embodiment, the shape of the transmission bar is changed as shown in FIG.

  That is, the transmission bar 180 according to the second embodiment has an “L” -shaped branch that branches off from the middle of the bar, and the tip portion on the side facing the light transmission member 11 has two locations (180a and 180b). ). Further, the distances between the tip portions 180a and 180b and the light transmission member 11 (low-pass filter 11a) are the same or substantially the same.

  Therefore, when the charge lever 170 collides with the transmission bar 180, the two tip portions 180a and 180b of the transmission bar 180 collide with the low-pass filter 11a almost simultaneously. In this case, the transmission bar 180 can efficiently transmit the rotational energy of the charge lever 170 to the low-pass filter 11a, thereby improving the foreign matter removal function.

  In addition, it is also possible to make the number of branches of the transmission bar 3 or more and cause the light transmission member to collide at three or more locations. Further, if possible according to design specifications, a cylindrical skirt portion can be attached to the transmission bar, and the bottom surface of the cylindrical skirt portion can collide with the light transmitting member.

[Third Embodiment]
In the first and second embodiments, the light transmission member 11 is provided between the focal plane shutter 50 and the solid-state imaging device 15, and foreign matters attached to the exposed surface of the light transmission member 11 are removed. However, as shown in FIG. 8, a configuration in which the light transmitting member 11 is not provided between the focal plane shutter 50 and the solid-state imaging device 15 and the focal plane shutter 50 and the solid-state imaging device 15 are directly opposed is also conceivable. In this case, foreign matter may adhere to the exposed surface of the cover glass 15 a of the solid-state imaging device 15.

  However, in this case, the transmission bar 178 according to the first embodiment or the transmission bar 180 according to the second embodiment is caused to collide with the cover glass 15a of the solid-state imaging device 15, thereby causing the cover glass 15a to be exposed. The adhered foreign matter can be removed.

  In the case where there is a possibility that the cover glass 15a is broken due to the collision of the transmission bar, the transmission bar may be configured to collide with the frame (holding member) holding the cover glass 15a.

[Fourth Embodiment]
In the first and second embodiments, the seal member 16 is interposed between the cover glass 15 a of the solid-state imaging device 15 and the infrared cut filter 11 b of the light transmission member 11. On the other hand, in the fourth embodiment, an elastic member 19 is used instead of the seal member 16 as shown in FIG.

  Similar to the seal member 16, the elastic member 19 has a function of sealing between the light transmission member 11 and the cover glass 15 a of the solid-state imaging device 15. Further, the elastic member 19 has an elastic coefficient defined so as to resonate at a predetermined frequency when a predetermined impact force is applied to the light transmitting member 11. Accordingly, the support plate 13 of the light transmission member 11 is fixed to the holding plate 18 at a location not shown in a state that resists the elastic force of the elastic member 19. Other configurations are the same as those in the first embodiment.

  Therefore, in the fourth embodiment, when the rotational energy of the charge lever 170 is transmitted to the low-pass filter 11a via the transmission bar 178, the low-pass filter 11a resonates due to the impact force and the resonance action of the elastic member 19. To do. The vibration (amplitude) of the low-pass filter 11a due to this resonance is larger than the vibration of the low-pass filter 11a when the transmission bar 178 only collides with the low-pass filter 11a. Therefore, in the fourth embodiment, the foreign substance removing function is improved as compared with the first embodiment.

  The transmission bar 178 is biased to the right and collides with the light transmission member only once or a few times, so that the resonance vibration of the elastic member 19 stops in a short time. Therefore, even when the elastic member 19 is provided as in the present embodiment, it is not necessary to shorten the predetermined time counted in step S107 in FIG. In other words, even if the elastic member 19 is provided, it is possible to quickly shift to an imaging operation for capturing an image without blurring.

  The present invention is not limited to the first to fourth embodiments described above. For example, the first to fourth embodiments may be appropriately combined. Further, the present invention can be applied not only to an interchangeable lens digital camera but also to an imaging device such as a digital camera that is not a interchangeable lens.

  Furthermore, a plurality of transmission bars such as transmission bars 178 and 180 can be provided. In this case, for example, as in the first to fourth embodiments, the predetermined transmission bar collides with the end 170c of the charge lever 170 when the mirror is raised, and the other transmission bars are when the mirror is lowered. It is conceivable to construct the battery so as to collide with the mirror arm 170b of the charge lever 170.

It is sectional drawing which shows schematic structure of the imaging device which concerns on the 1st-4th embodiment of this invention. It is sectional drawing which shows schematic structure of the imaging part of the said imaging device, and a focal plane shutter. It is a block diagram which shows the electrical structure of the said imaging device. (A) is a figure for demonstrating the mechanical drive state of the half mirror in the 1st Embodiment of this invention (mirror up state). (B) is a figure for demonstrating the mechanical drive state of the half mirror in the 1st Embodiment of this invention (mirror down-up state). It is a figure which shows the kinetic energy supply condition in the 1st Embodiment of this invention. It is a flowchart which shows the foreign material removal process accompanying the drive of the half mirror in the 1st-4th embodiment of this invention. It is a figure which shows the transmission member of the kinetic energy in the 2nd Embodiment of this invention. It is a figure which shows the member used as the object of the foreign material removal in the 3rd Embodiment of this invention. It is a figure which shows the resonance member in the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Light transmission member, 15 ... Solid-state imaging device, 15a ... Cover glass, 15b ... Solid-state image sensor, 19 ... Elastic member (resonance member), 111 ... Half mirror, 135 ... Camera system control part, 170 ... Charge lever, 170a ... arm part of charge lever, 173 ... charge spring, 178, 180 ... transmission bar

Claims (9)

In an imaging apparatus comprising an imaging means for converting an optical image of a subject into an electrical signal, a light transmission member disposed in front of the imaging means, and an imaging preparation means that operates before imaging by the imaging means,
An imaging apparatus comprising: a transmission member that transmits kinetic energy used when operating the imaging preparation means to the light transmission member.   2. The imaging according to claim 1, wherein the imaging preparation means is an optical path switching means, and the kinetic energy is energy supplied to the optical path switching means in order to switch the position of the optical path switching means. apparatus.   The imaging apparatus according to claim 1, wherein the transmission member is biased in a direction opposite to a direction facing the light transmission member.   The imaging apparatus according to claim 1, wherein the transmission member collides with one place of the light transmission member in response to the supply of the kinetic energy.   The imaging apparatus according to claim 1, wherein the transmission member collides with a plurality of locations of the light transmission member upon receiving the supply of the kinetic energy.   The imaging apparatus according to claim 1, wherein the transmission member collides with one portion of a holding member that holds the light transmission member by receiving the supply of the kinetic energy.   The imaging apparatus according to claim 1, wherein the transmission member collides with a plurality of positions of a holding member that holds the light transmission member by receiving the supply of the kinetic energy.   The imaging apparatus according to claim 4, wherein the light transmission has an exposed surface exposed to the outside, and the location of the collision is on the exposed surface side.   The imaging apparatus according to claim 1, further comprising a resonance member that resonates when the kinetic energy is supplied through the transmission member.

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