JP5153193B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging apparatus having a mirror unit and an imaging element.

  If there is a foreign object such as dust near the focal plane of the camera's taking lens, there is a problem that the shadow of the foreign object is reflected on the image sensor. Such foreign matter is caused by dust entering from the outside when the lens is replaced, or by fine abrasion powder such as resin that is a structural member due to the operation of the shutter or mirror inside the camera. It is considered. When foreign matter enters between the cover glass for protecting the image sensor and an optical filter such as an infrared cut filter or an optical low-pass filter (hereinafter abbreviated as LPF) disposed in front of the cover glass, The camera must be disassembled to remove the foreign material. Therefore, it is effective to provide a sealed structure that prevents foreign matter from entering between the cover glass of the image sensor and the optical filter.

  However, when a foreign object adheres to the surface of the optical filter that does not face the image sensor, if the adhesion position is in the vicinity of the focal plane, the adhered foreign object is reflected in the image sensor as a shadow. Still remains.

Therefore, in order to solve such problems, a dust-proof curtain that transmits the photographing light flux is provided on the subject side of the image sensor, and the dust-proof curtain is vibrated by a piezoelectric element so that dust adhered to the surface of the dust-proof curtain A technique for removing foreign substances has been proposed (see Patent Document 1).
JP 2003-319222 A

In Patent Document 1, if the foreign matter adhesion surface of the dustproof curtain gravity is directed to the surface in a direction opposite to that act, it is not possible to remove foreign matter.

The present invention has an object to provide a can be that imaging device be removed regardless of the posture of the imaging device foreign matter adhering to the optical member.

In order to achieve the above object, an image pickup apparatus of the present invention includes an image pickup device that photoelectrically converts a subject image, an optical member that is disposed closer to the subject than the image pickup device, and an excitation unit that vibrates the optical member. A shutter disposed closer to the subject than the optical member, a first state disposed closer to the subject than the shutter to reflect the light flux, and a first state for guiding the light flux to the imaging element without reflecting the light flux. An image pickup apparatus comprising: a mirror unit capable of switching to a state of 2; and a control means for controlling the excitation unit, the shutter, and the mirror unit, wherein the image pickup apparatus includes the shutter and the optical unit. Rutotomoni flow passage connecting the space and the space of the reflecting surface of the mirror unit between the member is formed, the imaging device comprises a closing means for opening and closing the flow path Wherein, when the mirror unit is in said first state, said opening the shutter and the closing means, after the opening of the shutter and the switching means is completed, the mirror unit and the first starts the operation for switching to the second state from the state, the switching operation is completed from the start of the switching Ru operation to said second state from said mirror unit the first state, to the second state Until the vibration unit is driven , and the shutter and the opening / closing unit are closed when the mirror unit is in the second state, and the shutter and the opening / closing unit are closed. , the mirror unit so as to start the operation of switching to the first state from said second state, said vibrating means, said shutter and said mirror And controlling the unit.

According to the present invention, the foreign matter attached to the optical member can be removed regardless of the posture of the imaging apparatus .

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic cross-sectional view for explaining a camera 100 as an example of an embodiment of the present invention. The camera 100 includes an imaging unit 101 that converts light energy into an electrical signal. On the front side of the camera 100, a mount portion 104 to which the interchangeable lens 102 is detachably attached is provided.

  The interchangeable lens 102 includes a plurality of lenses 102 a and 102 b for capturing reflected light from a subject and forming an image on the imaging unit 101, and an aperture mechanism 103 that adjusts the amount of light incident on the imaging unit 101.

  On the optical axis of the interchangeable lens 102 and the imaging unit 101, a main mirror 105 (mirror unit) is arranged in a space called a mirror box 107 (region indicated by a broken line in FIG. 1). The main mirror 105 reflects a part of the incident light beam in order to confirm the subject image by the user and guides it to the viewfinder 106 in the upper part of FIG.

  The finder 106 includes a focusing screen 108 on which the light beam reflected upward in FIG. 1 by the main mirror 105 forms an image, and a prism 109 that internally reflects the image so that the image formed on the focusing screen 108 becomes an erect real image. Is provided. The viewfinder 106 also includes an eyepiece lens 110 that changes the magnification of the image emitted from the prism 109 so that the user can confirm the image at an appropriate magnification. A partial region of the main mirror transmits incident light at a predetermined ratio, and the transmitted light beam is guided to the AF unit 112 by the sub mirror 111.

A focal plane shutter 113 (shutter member) having a plurality of shutter blades is disposed behind the main mirror 105. The focal plane shutter 113 is for adjusting the amount of light flux of the incident subject image, and irradiates the imaging unit 101 with the incident light flux for a desired time. Between the space S sandwiched between the imaging unit 101 and the focal plane shutter 113 and the space on the reflecting surface side of the main mirror 105 in the mirror box 107, there is a flow path for air to pass as shown in the figure. An opening / closing mechanism 114 that opens and closes the opening is provided in the flow path.

  The opening / closing mechanism 114 is a mechanism for connecting or blocking between the space S and the mirror box 107 by opening / closing an opening by the driving mechanism 210. Reference numerals 116, 117, and 118 denote adhesive members (foreign matter capturing members) for capturing foreign matters.

  The space from the interchangeable lens 102 side of the mirror box 107 through the focal plane shutter 113 to the interchangeable lens 102 side of the imaging unit 101 has a substantially sealed structure. As a result, while the interchangeable lens 102 is mounted, the structure is such that the outflow of air from the region A and the inflow of air into the region A can hardly be performed.

  Reference numeral 115 denotes a change-over switch (setting unit) for the user to switch between the imaging mode and the cleaning mode.

  FIG. 2 is a cross-sectional view of the imaging unit 101, the mirror box 107, the focal plane shutter 113, and the periphery thereof.

  As shown in FIG. 2, the imaging unit 101 includes an imaging element 119 that photoelectrically converts a subject image and an LPF 122 (optical member). The image sensor 119 is housed in the package member 120 and protected by the protection member 121. The LPF 122 is vibrated by a vibration member 124 (vibration means) having a laminated piezoelectric element in a cleaning mode to be described later, thereby removing foreign matters attached to the LPF 122. Further, the space between the package member 120 and the LPF 122 and the space between the wall 131 forming the region A and the LPF 122 are sealed by the elastic member 123, and the vibration of the LPF 122 is not transmitted to the region A and the package member 120. It is like that.

  The focal plane shutter 113 has a front curtain 125 composed of four shutter blades 125a to 125d and a rear curtain 126 composed of four shutter blades. The front curtain 125 and the rear curtain 126 travel so that the respective shutter blades are deployed or overlapped. Then, the amount of light incident on the imaging unit 101 is adjusted by the slit width formed between the front curtain 125 and the rear curtain 126. Further, the front curtain 125 is pressed by a presser plate 128, and an opening for imaging is provided at a substantially central portion of the presser plate 128. The rear curtain 126 is pressed by a presser plate 129, and an opening for imaging is provided at a substantially central portion of the presser plate 129. The driving space for the front curtain 125 and the driving space for the rear curtain 126 are partitioned by an intermediate plate 127.

  Next, the control system of the camera 100 will be described with reference to FIG.

  As shown in FIG. 3, the camera 100 is provided with a camera system control unit 201 (control means), a mirror control unit 205, an opening / closing mechanism control unit 206, a shutter control unit 207, and an excitation control unit 208.

  The camera system control unit 201 includes a CPU 202, a ROM 203, a RAM 204, a timer 212, and the like, and controls the entire camera and performs various individual controls. The mirror control unit 205 drives the main mirror 105 by the drive mechanism 209 based on the control signal from the camera system control unit 201.

  The opening / closing mechanism control unit 206 drives the opening / closing mechanism 114 by the drive mechanism 210 based on a control signal from the camera system control unit 201. The shutter control unit 207 drives the focal plane shutter 113 by the drive mechanism 211 based on a control signal from the camera system control unit 201. The vibration control unit 208 drives the vibration member 124 based on a control signal from the camera system control unit 201.

  Next, an example of the cleaning operation of the camera 100 will be described with reference to FIGS. FIG. 4 is a flowchart for explaining the sequence of the cleaning operation of the camera 100. 5 and 6 are schematic cross-sectional views of the imaging unit 101, the mirror box 107, the focal plane shutter 113, and their peripheral parts during the cleaning operation corresponding to the sequence of FIG. Here, each process in FIG. 4 is executed by the CPU 202 after a control program stored in the ROM 203 or the like of the camera system control unit 201 is loaded into the RAM 204.

  First, in step S1, the user enters a standby state as shown in FIG. 5A until the user operates the mode switch 115 to select the cleaning mode. At this time, it is assumed that the foreign matter 130 is attached to the LPF 122. When the cleaning mode is selected by the user, the process proceeds to step S2.

  In step S2, as shown in FIG. 5B, the shutter blades 125a to 125d of the leading curtain 125 in the unfolded state travel downward in FIG. 5 so as to be in a superimposed state, and go to step S3. And migrate.

  In step S3, the opening / closing mechanism 114 brings the space S between the imaging unit 101 and the focal plane shutter 113 into communication with the mirror box 107, and the process proceeds to step S4.

  In step S4, it is confirmed by a switch (not shown) that the operation in step S2 and the operation in step S3 are completed, and the process proceeds to step S5.

  In step S5, the main mirror 105 and the sub mirror 111 start a mirror up operation (switching operation from the first state to the second state). When the mirror up operation is started, the process proceeds to step S6.

  In step S6, as shown in FIG. 6A, the vibration member 124 is driven to start the foreign matter removing operation. When the vibration member 124 is driven, the foreign material 130 is lifted from the LPF 122 or has a reduced adhesive force. Then, as shown in FIG. 6B, the air in the space above the main mirror 105 in FIG. 5 is shown by the arrow X in FIG. 6B by the mirror-up operation started in step S5. , Flows into the front surface of the LPF 122. The air flowing into the front surface of the LPF 122 passes through the opening of the focal plane shutter 113 and is guided into the mirror box 107.

  Here, the reason why air flows as indicated by an arrow X will be described. During the mirror up operation, the air in the space above the main mirror 105 is compressed as the main mirror 105 gradually reduces the distance from the upper part of the mirror box 107. At this time, the opening / closing mechanism 114 provided above the main mirror 105 is opened to create an air escape path above the main mirror 105, so that the air above the main mirror 105 is communicated by the opening / closing mechanism 114. Guided to space.

  On the other hand, since the space below the main mirror 105 has a negative pressure, the air existing in the opening space of the focal plane shutter 113 and the space in front of the imaging unit 101 is guided to the mirror box 107 side. As described above, an air flow as indicated by an arrow X in FIG.

Most of the foreign matter 130 that has risen from the LPF 122 or has reduced adhesion force is guided to the mirror box 107 side and is captured by the adhesive member 118 provided at the site where the air collides. Further, in FIG. 5, the foreign matter 130 in FIG. 6 (b) which is attached to the underside of the LPFs 122, the flow Y weak air flowing on the lower side, in FIG. 6 (b), the head to the lower side, adhesive Captured by member 117. Therefore, it is possible to prevent the foreign matter 130 guided from the LPF 122 to the mirror box 107 side from reattaching to the LPF 122.

  Even if foreign matter remains in the mirror box 107, the air flow X collides with the adhesive member 116 disposed in the air flow path from the mirror box 107 to the front surface of the LPF 122, so that the inside of the mirror box 107 The moved foreign matter is captured by the adhesive member 116. Accordingly, the foreign matter present in the mirror box 107 does not move to the front surface of the LPF 122 and therefore does not reattach to the LPF 122.

  Next, in step S7, when the completion of the mirror up operation is confirmed by a switch (not shown), the process proceeds to step S8.

  In step S8, when the timer 212 confirms that several seconds have elapsed after completion of the mirror up operation, the process proceeds to step S9.

  In step S9, the opening / closing mechanism 114 is driven to enter a blocking state that shields the space S between the imaging unit 101 and the focal plane shutter 113 and the mirror box 107, and the process proceeds to step S10.

  In step S10, the shutter blades 125a to 125d of the front curtain 125 that have been in the superimposed state travel upward in FIG. 5 so as to be in the unfolded state, and the process proceeds to step S11.

  In step S11, when it is confirmed by a switch (not shown) that the front curtain 125 is in the unfolded state, the process proceeds to step S12.

  In step S12, the main mirror 105 and the sub mirror 111 are driven to complete the mirror down operation. And it will be in a standby state as shown to Fig.5 (a).

  Thus, a series of cleaning operations of the camera 100 is completed.

  Next, the significance of the existence of the opening / closing mechanism 114 will be described.

  During imaging, only the light beam that has passed through the opening of the focal plane shutter 113 from the interchangeable lens 102 must be incident on the imaging unit 101.

  However, if there is no opening / closing mechanism 114 and the mirror box 107 and the space S sandwiched between the imaging unit 101 and the focal plane shutter 113 are always in communication, light other than the desired light flux is transmitted from the communication part to the imaging unit 101. There is a risk of incidence.

  Therefore, the mirror box 107 and the space S sandwiched between the imaging unit 101 and the focal plane shutter 113 are always cut off during shooting, and the mirror box 107 and the space S are opened only during the cleaning mode. It is preferable to do. For this reason, the opening / closing mechanism 114 is provided in the present embodiment.

  FIG. 7 shows the imaging unit 101 and the mirror box at the same timing as FIG. 6B in the camera posture in which the foreign matter adhesion surface of the LPF 122 faces the direction opposite to the direction in which gravity acts (indicated by the arrow G in FIG. 7). FIG. 7 is a cross-sectional view of 107, a focal plane shutter 113 and its peripheral part.

  Even in the posture of the camera 100 as shown in FIG. 7, the air in the right space of FIG. 7 of the main mirror 105 flows as shown by the arrow X by the mirror up operation. As in the case of the posture of the camera 100 shown in FIG. 6, the foreign material 130 riding on the air flow indicated by the arrow X is captured by the adhesive member 118. Further, the foreign matter 130 attached to the left side of the LPF 122 in FIG. 7 is captured by the adhesive member 117 by the weak air flow Y. Therefore, it is possible to prevent the foreign matter 130 guided from the LPF 122 toward the mirror box 107 from reattaching to the LPF 122.

  Even if foreign matter remains in the mirror box 107, the air flow X collides with the adhesive member 116 disposed in the air flow path from the mirror box 107 to the front surface of the LPF 122, so that the inside of the mirror box 107 The moved foreign matter is captured by the adhesive member 116. Accordingly, the foreign matter present in the mirror box 107 does not move to the front surface of the LPF 122 and therefore does not reattach to the LPF 122.

  As described above, in this embodiment, the foreign matter attached to the LPF 122 can be reliably removed regardless of the posture of the camera 100 and can be prevented from being attached again to the LPF 122. Further, the foreign matter removed from the LPF 122 can be guided and effectively captured in a direction in which the foreign matter capturing member such as the adhesive members 116, 117, and 118 is located. As a result, the foreign matter 130 removed from the LPF 122 adheres to other structures, and the foreign matter 130 can be prevented from reattaching to the LPF due to camera vibration or the like.

  In addition, this invention is not limited to what was illustrated to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.

  For example, in the above-described embodiment, the adhesive members 116, 117, and 118 are exemplified as the foreign material capturing member. However, instead of the adhesive member, the foreign material may be captured by an electrostatic force generated by a charging member such as an electret member. .

It is a schematic sectional drawing for demonstrating the camera which is an example of embodiment of this invention. It is sectional drawing of an imaging part, a mirror box, a focal plane shutter, and its peripheral part. It is a block diagram for demonstrating the control system of a camera. It is a flowchart for demonstrating the sequence of the cleaning operation | movement of a camera. FIG. 5 is a cross-sectional view of an imaging unit, a mirror box, a focal plane shutter, and its peripheral part during a cleaning operation corresponding to the sequence of FIG. 4. FIG. 5 is a cross-sectional view of an imaging unit, a mirror box, a focal plane shutter, and its peripheral part during a cleaning operation corresponding to the sequence of FIG. 4. FIG. 7 is a cross-sectional view of an imaging unit, a mirror box, a focal plane shutter, and their peripheral parts at the same timing as in FIG. 6B in a camera posture in which the foreign matter adhesion surface of the LPF faces a direction opposite to the direction in which gravity acts.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Camera 101 Image pick-up part 105 Main mirror 107 Mirror box 113 Focal plane shutter 114 Opening / closing mechanism 115 Mode changeover switch 116,117,118 Adhesive member 119 Image pick-up element 122 LPF
124 Excitation member 130 Foreign matter 201 Camera system control unit X flow path

Claims (1)

An image sensor that photoelectrically converts a subject image;
An optical member disposed closer to the subject than the image sensor;
Vibration means for vibrating the optical member;
A shutter disposed closer to the subject than the optical member;
A mirror unit that is disposed closer to the subject than the shutter and is capable of switching between a first state that reflects the light beam and a second state that leads to the imaging element without reflecting the light beam;
An imaging apparatus comprising: the excitation means, the shutter, and a control means for controlling the mirror unit,
The said imaging device, said shutter and said the flow path forming connecting the space and the space of the reflecting surface of the mirror unit between the optical member Rutotomoni, the imaging device, to open and close the flow channel opening and closing With means,
The control means opens the shutter and the opening / closing means when the mirror unit is in the first state, and after the opening of the shutter and the opening / closing means is completed , moves the mirror unit to the first starts the operation for switching to the second state from the state, the switching operation is completed from the start of the switching Ru operation to said second state from said mirror unit the first state, to the second state Until the vibration unit is driven , and the shutter and the opening / closing unit are closed when the mirror unit is in the second state, and the shutter and the opening / closing unit are closed. , the mirror unit so as to start the operation of switching to the first state from said second state, said vibrating means, said shutter and said mirror Imaging device and controls the knit.

Images