JP5836622B2 - Imaging device - Google Patents

Description

  The present invention relates to an imaging apparatus such as a single-lens reflex camera.

  In an imaging apparatus such as a digital camera, when dust such as dust adheres to the imaging surface of the image sensor, the attached portion becomes a black dot and is reflected in the captured image, so that the appearance of the image is deteriorated.

  In particular, in a single-lens reflex camera with interchangeable lenses, a mechanical drive unit such as a shutter or a mirror is disposed in the vicinity of the imaging surface, and highly sticky dust containing wear powder or grease generated in the drive unit is captured on the imaging surface. There is a risk of sticking to the shutter curtain.

  There has been proposed a technique for preventing dust from adhering to an imaging surface and a shutter curtain by providing a cartridge-shaped protective member on the imaging surface (Patent Document 1).

JP 2003-198916 A

  However, in Patent Document 1, since the protection member needs to be retracted from the imaging surface when the mirror is driven, dust scattered from the rotating shaft of the mirror or the mirror driving unit when the mirror is driven is captured on the imaging surface or the shutter. Cannot prevent sticking to the curtain.

  Accordingly, the present invention provides an imaging apparatus capable of preventing dust generated during the rotation of the mirror from scattering into the space on the image plane side from the mirror and preventing dust from adhering to the imaging surface, shutter curtain, and the like. The purpose is to provide.

In order to achieve the above object, an imaging apparatus of the present invention has a mirror, a rotation shaft fixed, a holding member that holds the mirror, a shaft fitting portion, and a rotation shaft shielding portion, and the shaft A first cover member whose fitting portion is extrapolated to the rotary shaft, a support member which is rotatably supported by the rotary shaft from which the first cover member is extrapolated, and a drive which drives the holding member comprising a member, the first cover member is mounted so as not to rotate relative to the support member, the rotary shaft shielding portion has an arc-like shape, the rotary shaft shielding portion said shaft A gap between the fitting portion and the support member is shielded.

According to the present invention, it is Ru can dust generated during rotation of the mirror is prevented from scattering to the space on the image plane side of the mirror.

1 is a schematic cross-sectional view of a digital single-lens reflex camera that is a first embodiment of an imaging apparatus of the present invention. It is the figure which looked at the drive part of the mirror unit from the X direction of FIG. (A) is a diagram showing a mirror-down state in which the mirror unit has entered the imaging optical path, (b) is a diagram showing a mirror-up state in which the mirror unit is retracted from the imaging optical path, and (c) is an imaging in the state (b). It is a figure which shows the state which the mirror unit entered into the imaging | photography optical path again after operation | movement. (A) is a disassembled perspective view of a mirror unit, a rotating shaft, a cover member, and a drive part support member, (b) is an enlarged perspective view of a cover member. (A) is sectional drawing for demonstrating the positional relationship of the cover member and the shutter base plate extrapolated by the rotating shaft, (b) is the figure which looked at the shutter base plate from the back side. It is a disassembled perspective view for demonstrating the cover member of a drive shaft. It is a figure explaining the relationship between the width L of a hole, and the diameter D of a cover member. In the digital single-lens reflex camera which is 2nd Embodiment of the imaging device of this invention, it is a disassembled perspective view of a mirror unit, a rotating shaft, a cover member, and a drive part support member.

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

(First embodiment)
FIG. 1 is a schematic cross-sectional view of a digital single-lens reflex camera which is a first embodiment of an imaging apparatus of the present invention. In the present embodiment, for convenience of explanation, the left direction in FIG. 1 will be described as the Z direction, the upward direction as the Y direction, and the back direction in the drawing as the X direction.

  As shown in FIG. 1, in the digital single-lens reflex camera of this embodiment, a lens barrel 1a is detachably attached to a camera body 1. Further, the mirror body 10 is supported on the camera body 1 so as to be rotatable with respect to a mirror box (not shown). The mirror unit 10 includes a main mirror 100 composed of a half mirror, and a sub mirror 200 that is rotatably supported with respect to the main mirror 100. The mirror unit 10 then enters the imaging optical path (mirror down) during viewfinder observation, and retracts (mirrors up) from the imaging optical path during imaging due to the rotation operation.

  When the mirror unit 10 is in the mirror-down state, the luminous flux of the subject that has entered the imaging optical path through the lens barrel 1 a is divided into a luminous flux that is reflected upward by the main mirror 100 and a luminous flux that is transmitted through the main mirror 100.

  The light beam reflected upward by the main mirror 100 is guided to the eyepiece 16 and the photometry device 15 via the penta roof prism 14 and the like, and the light beam transmitted through the main mirror 100 is reflected by the sub mirror 200 and is disposed below. It is guided to the detection device 11. Exposure control during exposure is performed based on the output signal of the photometry device 15, and driving of the lens barrel 1 a is controlled based on the output sound signal of the focus detection device 11.

  On the other hand, when the mirror unit 10 is in the mirror-up state, the light flux of the subject that has passed through the lens barrel 1 a and entered the imaging optical path passes through the shutter base plate 500 and the shutter curtain 12 and forms an image on the image sensor 13. The image formed on the image sensor 13 is displayed on a display device (not shown) provided on the back surface of the camera body 1 and is recorded as image data on a recording medium (not shown).

  Next, the drive unit 120 of the mirror unit 10 will be described with reference to FIG. FIG. 2 is a view of the drive unit 120 of the mirror unit 10 as viewed from the X direction of FIG.

  As shown in FIG. 2, the drive unit 120 includes an up lever 301 that retracts the mirror unit 10 from the imaging optical path, a down lever 302 that causes the mirror unit 10 to enter the imaging optical path, and a hook lever 303 that engages with the down lever 302. Is provided. The up lever 301 and the down lever 302 are supported by a screw 300 so as to be rotatable coaxially with the mirror box. A hook lever 303 is rotatably supported by the up lever 301, and the up lever 301 is urged counterclockwise by a spring member 304 in the drawing.

  3A and 3B are diagrams showing the relationship between the mirror unit 10 and the drive unit 120. FIG. 3A is a diagram showing a mirror-down state in which the mirror unit 10 has entered the imaging optical path, and FIG. FIG. 6 is a diagram showing a mirror-up state where the mirror is retracted from the photographing optical path. FIG. 3C is a diagram illustrating a state in which the mirror unit 10 enters the photographing optical path again after the photographing operation in the state of FIG. In FIG. 3, illustration of a drive unit support member 113 (described later) disposed between the holding plate 102 and the drive unit 120 is omitted.

  As shown in FIG. 3A, the main mirror 100 is held by a holder 101, and holding plates 102 are fixed to both sides of the holder 101 in the X direction. The holder 101 is urged counterclockwise by a spring member 305 in the drawing. Here, the holding plate 102 corresponds to an example of the holding member of the present invention.

  The holding shaft 102 is fitted and fixed with a rotation shaft 110 serving as a rotation center of the main mirror 100, and a drive shaft 114 to which a driving force is transmitted from the drive unit 120 is arranged in parallel with the rotation shaft 110. It is fixed.

  The sub mirror 200 is held by a holder 201, and the holder 201 is rotatable with respect to the main mirror 100 about a rotation shaft 104 provided on the holding plate 102. Further, the holder 201 is urged counterclockwise by a spring member 205 in the drawing.

  In the state of FIG. 3A, the up lever 301 is rotated clockwise against the urging force of the spring member 304 by a drive source (not shown) to charge the spring member 304, and the engagement lever (not shown). The stop lever is stopped by being engaged with the bent portion 301 a of the up lever 301.

  In the state of FIG. 3B, based on the photographing signal, the locking of the bent portion 301a of the up lever 301 by the locking lever is released, and the up lever 301 is rotated counterclockwise in the figure by the biasing force of the spring member 304. Rotate. Since the spring member 304 has a sufficiently larger urging force than the spring member 305, the down lever 302 engaged with the hook lever 303 also rotates together with the up lever 301. Then, the down lever 302 operates the roller 111 of the drive shaft 114 to retract the mirror unit 10 from the photographing optical path.

  In the state of FIG. 3C, the hook lever 303 is rotated in the clockwise direction in the drawing based on the photographing completion signal, and the engagement with the down lever 302 is released. Then, the mirror unit 10 is rotated counterclockwise in the figure by the biasing force of the spring member 305, and the down lever 302 is pressed by the roller 111 of the drive shaft 114, whereby the down lever 302 is rotated in the clockwise direction in the figure. Rotate.

  Thereafter, in preparation for the next shooting, the up lever 301 is rotated in the clockwise direction in the figure against the biasing force of the spring member 304 to charge the spring member 304, and the state shown in FIG. Become.

  Next, the cover member 107 of the rotating shaft 110 fitted to the holding plate 102 of the holder 101 will be described with reference to FIG. 4A is an exploded perspective view of the mirror unit 10, the rotating shaft 110, the cover member 107, and the drive unit support member 113, and FIG. 4B is an enlarged perspective view of the cover member 107. FIG. Here, the cover member 107 corresponds to an example of the first cover member of the present invention.

  As shown in FIG. 4, the cover member 107 is made of a metal or resin and has a thin, substantially cylindrical shape, and includes a shaft fitting portion 107 a and a rotation shaft shielding portion 107 b. The shaft fitting portion 107a has a cylindrical shape, and is coaxially extrapolated with respect to the rotation shaft 110 so as to cover the entire outer periphery of the rotation shaft 110. The rotating shaft shielding part 107b has an arc plate shape and is integrally provided at the end of the shaft fitting part 107a on the drive part supporting member 113 side.

  The drive unit support member 113 is disposed between the holding plate 102 of the mirror unit 10 and the drive unit 120. The drive unit support member 113 is in contact with the drive unit support member 113 on both sides in the circumferential direction of the rotating shaft shielding unit 107b. A rotation stopper 107 c that restricts the rotation of the cover member 107 is provided.

  Here, in a state where the rotation of the cover member 107 is restricted, the rotation shaft shielding portion 107b is disposed so as to face the shutter curtain 12 and the image sensor 13 side. Therefore, the space between the shaft fitting portion 107a and the drive portion support member 113 is formed by the rotating shaft shielding portion 107b with respect to the space closer to the image plane than the mirror unit 10, that is, the space closer to the imaging surface and the shutter curtain 12. Shielded.

  As a result, the space between the image plane side of the mirror unit 10 and the rotary shaft 110 is shielded, and dust such as abrasion powder generated on the rotary shaft 110 during the rotation of the mirror unit 10 is captured on the imaging surface or the shutter curtain 12 side. Can be prevented from being scattered. When assembling, after the shaft fitting portion 107 a is extrapolated to the rotating shaft 110 fitted to the holding plate 102, the rotating shaft 110 is fitted into the driving portion support member 113.

  5A is a cross-sectional view for explaining the positional relationship between the cover member 107 extrapolated on the rotating shaft 110 and the shutter base plate 500, and FIG. 5B is a view of the shutter base plate 500 viewed from the back side. is there.

  The main mirror 100 is preferably arranged on the shutter base plate 500 side as much as possible in order to reduce the size of the camera. Therefore, the shutter base plate 500 is formed with a notch 501 in which the rotary shaft shielding portion 107b, which is a part of the cover member 107, is accommodated, whereby the rotary shaft 110 of the main mirror 100 is arranged close to the shutter base plate 500 side. Making it possible. In the present embodiment, the cover members 107 of the rotating shaft 110 are disposed on both sides of the main mirror 100, but may be disposed on only one side as necessary.

  Next, the cover member 108 of the drive shaft 114 will be described with reference to FIGS. FIG. 6 is an exploded perspective view for explaining the cover member 108 of the drive shaft 114.

  As shown in FIGS. 5A and 6, the support shaft 112 is fixed to the holding plate 102 so as to be parallel to the rotation shaft 110, and the support shaft 112 is formed on the drive unit support member 113. It is disposed so as to penetrate through the hole 113a and project toward the down lever 302 side of the drive unit 120. Further, a small diameter portion 112b is formed at the tip of the support shaft 112.

  An annular plate-shaped cover member 108 having a larger diameter than the roller 111 is extrapolated to the small diameter portion 112b of the support shaft 112 so as to close the hole 113a. Thereafter, the roller 111 is rotatably fitted to the small-diameter portion 112b of the support shaft 112, and the cover member 108 is sandwiched in the axial direction between the roller 111 and the step surface 112a of the small-diameter portion 112b of the support shaft 112. 114 is constituted.

  FIG. 7 is a view for explaining the relationship between the width L of the hole 113a formed in the driving unit support member 113 and the diameter D of the cover member 108. FIG. As shown in FIG. 7, the diameter D of the cover member 108 is sufficiently larger than the width L of the hole 113a. As a result, even if dust containing grease or the like adhering to the holding plate 102 or the like is scattered during the rotation operation of the mirror unit 10, the scattered dust is blocked by the cover member 108 outside the hole 113a and adheres to the cover member 108. To do. Therefore, it is possible to prevent dust containing scattered grease and the like from entering the inside of the hole 113a.

  In addition, since the cover member 108 is rotatable coaxially with the roller 111, dust can be prevented from adhering to a certain region. The scattered dust may be adsorbed by sticking a double-sided tape or the like to the cover member 108 to make the surface sticky. Here, the cover member 108 corresponds to an example of a second cover member of the present invention.

  As described above, in the present embodiment, dust generated during the rotation operation of the mirror unit 10 is prevented from being scattered on the image pickup surface of the image pickup device 13 arranged on the image plane side than the mirror unit 10 and the shutter curtain 12 side. can do. Thereby, it is possible to prevent dust from adhering to the image pickup surface of the image pickup device 13 and the shutter curtain 12, and to prevent the reflection of dust on the picked-up image and the obstruction of the running of the shutter curtain 12. it can.

(Second Embodiment)
Next, a digital single-lens reflex camera which is a second embodiment of the imaging apparatus of the present invention will be described with reference to FIG. In addition, about the part which overlaps with the said 1st Embodiment, description is abbreviate | omitted and only a different point is demonstrated, using a code | symbol.

  In the present embodiment, a cover member 107A is used in place of the cover member 107 of the first embodiment (FIG. 4). FIG. 8 is an exploded perspective view of the mirror unit 10, the rotating shaft 110, the cover member 107 </ b> A, and the drive unit support member 113.

  As shown in FIG. 8, the cover member 107A is formed with a concave portion 107d corresponding to the outer peripheral portion of the rotating shaft 110, and positioning holes 107e are formed on both sides of the concave portion 107d in the Y direction in FIG. Is formed.

  The concave portion 107d is accommodated in a notch 501 formed in the shutter base plate 500, and the cover member 107A does not interfere with the rotating shaft 110, the shutter base plate 500, and the shutter curtain 12.

  Then, the positioning hole 107e of the cover member 107A is fitted and positioned in the positioning convex portion 500a formed on the shutter base plate 500, and in this state, the cover member 107A is fixed to the shutter base plate 500 with a double-sided tape or an adhesive.

  Thereby, it is possible to prevent dust such as wear powder generated on the rotating shaft 110 during the rotation operation of the mirror unit 10 from being scattered on the imaging surface or the shutter curtain 12 side. The method for fixing and positioning the cover member 107A and the shutter base plate 500 is not particularly limited. Other configurations and operational effects are the same as those in the first embodiment.

  The configuration of the present invention is not limited to those exemplified in the above embodiments, and the material, shape, dimensions, form, number, arrangement location, and the like are appropriately changed without departing from the gist of the present invention. Is possible.

12 Shutter curtain 13 Image sensor 107 Cover member 108 Cover member 110 Rotating shaft 113 Holding plate 114 Drive shaft 120 Drive unit 500 Shutter base plate

Claims (4)

Mirror,
A rotating shaft is fixed, and a holding member for holding the mirror;
A first cover member having a shaft fitting portion and a rotation shaft shielding portion, wherein the shaft fitting portion is extrapolated to the rotation shaft;
A support member that is rotatably supported by the rotation shaft on which the first cover member is extrapolated;
A drive member for driving the holding member,
The first cover member is mounted so as not to rotate relative to the support member,
The rotation shaft shielding portion has an arc plate shape, and the rotation shaft shielding portion shields a gap between the shaft fitting portion and the support member. A support shaft parallel to the rotation shaft is fixed to the holding member,
The support member is formed with a hole through which the support shaft is inserted,
The support shaft protruding from the hole is extrapolated to the support shaft so that a second cover member closes the hole,
A roller member is extrapolated to the support shaft protruding from the second cover member,
The imaging apparatus according to claim 1, wherein the driving member drives the holding member by contacting the driving member with the roller member.   The imaging apparatus according to claim 1, wherein the second cover member has adhesiveness on a surface. A shutter base plate disposed to face the first cover member;
The imaging apparatus according to claim 1, wherein the rotation shaft shielding portion is accommodated in a notch formed in the shutter base plate.

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