JP5896585B2 - Single-lens reflex camera - Google Patents

Description

The present invention also relates to a single-lens reflex camera.

  The single-lens reflex camera is configured to perform shooting based on a subject light beam incident from a photographing lens and to observe the subject based on the subject light beam incident from the photographing lens. In general, a single-lens reflex camera is a mirror device that switches the light flux of a subject from a photographic lens to the shooting side on the film or imaging device side or to the observation side in terms of time. The quick return mirror is arranged.

  In addition, many of the cameras released in recent years have an autofocus (AF) mechanism, and a representative example of an AF mechanism that a single-lens reflex camera has is TTL phase difference AF. A single-lens reflex camera capable of this TTL phase difference AF generally has the following structure.

  A part of the main mirror that can be rotated to the mirror down position for reflecting the subject light flux from the photographing lens and the mirror up position retracted from the subject light flux is configured as a semi-transmissive portion. Then, a sub-mirror for reflecting the subject light beam that has passed through the semi-transmissive portion at the observation position is provided on the back side of the semi-transmissive portion, and distance measurement for phase difference AF is performed on the optical path of the subject light beam reflected by the sub-mirror. Place the sensor. The sub-mirror is configured to be folded along the main mirror and retract from the subject light beam when the main mirror is in the mirror up position. A quick return mirror of a single-lens reflex camera provided with such a sub mirror is disclosed in, for example, Japanese Patent Application Laid-Open No. 2007-114511.

  In the single-lens reflex camera as described above, when the quick return mirror is moved to the mirror up position, the quick return mirror bounces due to the impact, and the bounced quick return mirror is reflected in the photograph, There may be a problem that it cannot follow high-speed mirror drive.

As a method of avoiding such a malfunction due to the bounce of the quick return mirror, a method of suppressing the bounce of the quick return mirror by providing a buffer material at the positioning position of the quick return mirror is common.
JP 2007-114511 A

By the way, when the quick return mirror is moved to the mirror down position, if the sub mirror bounces due to an impact, accurate distance measurement cannot be performed until the bounce is settled, and the continuous shooting speed is reduced. However, it is not easy for the conventional single-lens reflex camera to reduce the bounce of the submirror.

The present invention has been made in view of the above problems, and an object thereof is to provide a sub-mirror bounce, a single-lens reflex camera capable of reducing the bounce of the entire turn mirror device.

Single-lens reflex camera according to the present invention, rotatable between a first position, the main mirror holding frame which supports the main mirror to move between different from this second position, the main mirror holding frame a mirror box having a pair of side wall portions for supporting, in order to fit position-decided the main mirror holding frame in the first position, so as to be in contact with the said main mirror holding frame in the first position, the In a state where the first stopper provided on one of the pair of side wall surface portions and the main mirror holding frame are statically positioned by the first stopper, the main mirror holding frame is at a position separated from the main mirror holding frame. in the dynamic state the main mirror holding frame is moved to the first position from the second position, the first stopper abuts to deform the said main mirror holding frame and to abut , Having a main mirror buffer stopper provided on the other of the pair of sidewall portions.

  Hereinafter, an embodiment in which the present invention is applied to an interchangeable lens single-lens reflex camera will be described with reference to the drawings.

  FIG. 1 is a longitudinal sectional view showing a configuration of a camera body of a single-lens reflex camera. FIG. 2 is a side view of the mirror device in the mirror down position. FIG. 3 is a side view of the mirror device at the mirror-up position. FIG. 4 is a view of the mirror device in the mirror down position as viewed from below. FIG. 5 is a perspective view of the mirror device in the mirror down position as viewed from the back side. FIG. 6 is a diagram showing the positional relationship between the mirror in the mirror down position and the buffer stopper. FIG. 7 is a diagram showing a configuration of the bearing portion.

  First, a schematic configuration of a single-lens reflex camera according to the present embodiment will be described with reference to FIGS.

  A camera body 1 of a single-lens reflex camera includes a mirror device 2, an imaging unit 3, a finder unit 4, a distance measuring unit 5, a display unit 6, and a strobe unit 7.

  A body mount 11 is provided in front of the mirror device 2, and the photographing lens 1 a can be attached to and detached from the camera body 1 via the body mount 11.

  In the following description, the term “optical path” refers to the optical path of a subject luminous flux incident through the photographing lens 1a when the photographing lens 1a is attached to the body mount 11, and there are exceptions. Will clearly state that.

  In the following description, as shown in FIG. 1, the left-right direction of the single-lens reflex camera is the X direction, the vertical direction orthogonal to the X direction is the Y direction, and the front-rear direction orthogonal to the X and Y directions is the Z direction. And The Z direction is a direction parallel to the optical axis O of the photographing lens 1a (the thickness direction of the camera body 1). In the Z direction, the subject side of the camera body 1 is the front side (front side), and the photographer side is the rear side. (Back side). The left-right direction in the X direction is the direction of the camera body 1 viewed from the back side. That is, the front side is the left side when facing the paper surface of FIG.

  A mirror box 12 is disposed at the rear of the optical path of the body mount 11, and a mirror device 2 described later in detail is disposed in the mirror box 12. The mirror device 2 includes a main mirror 13 and a sub mirror 14 which are two reflection mirrors arranged so as to be able to advance and retreat on the optical path of a subject light beam.

  The main mirror 13 has a reflecting mirror surface and is supported in a mirror box 12 by a frame-shaped main mirror holding frame 41 rotatably disposed around a main mirror rotation shaft 41a. On the back side of the main mirror holding frame 41, a sub mirror holding frame 61 is supported so as to be rotatable around a sub mirror rotating shaft 61a. The sub mirror 14 is supported by the sub mirror holding frame 61. The main mirror rotation shaft 41a and the sub mirror rotation shaft 61a are substantially parallel to each other and are arranged along a plane orthogonal to the optical axis O of the photographing lens 1a.

  The main mirror 13 is configured such that at least a part of the reflecting mirror surface is a semi-transmissive portion, and the main mirror holding frame 41 is formed with an opening 42 which is a through hole, and is transmitted through the semi-transmissive portion of the main mirror 13. The luminous flux to be transmitted is transmitted to the back side of the main mirror holding frame 41. The sub mirror 14 is disposed on the optical axis of the light beam that passes through the semi-transmissive portion of the main mirror 13.

  The main mirror 13 has a mirror down position (observation position) that is a first position that has advanced on the optical path of the subject luminous flux as shown in FIG. It is positioned at one of two positions: a mirror-up position (retracted position) that is a second position retracted from the optical path of the subject luminous flux as shown.

  The sub mirror 14 has a reflecting mirror surface, and rotates around the sub mirror rotation shaft 61a in conjunction with the movement of the main mirror 13 by a cam, a spring mechanism, etc. (not shown). When the main mirror 13 is in the mirror down position, the sub mirror 14 is positioned at a position (first position) where the light beam transmitted through the semi-transmissive portion of the main mirror 13 is reflected in a predetermined direction on the back side of the main mirror 13. Is done. Further, when the main mirror 13 is in the mirror up position, the sub mirror 14 is folded to the main mirror 13 side and positioned at a position (second position) retracted from the optical path of the subject light beam.

  An imaging unit 3 that is an imaging unit is disposed behind the optical path of the subject light flux when the main mirror 13 and the sub mirror 14 are in the mirror up position. The imaging unit 3 includes a shutter device 15 for controlling the passage time of the subject light flux, and an imaging device 16 disposed on the rear side of the optical path of the shutter device 15.

  On the other hand, a finder unit 4 as an observation optical system is disposed on the optical path of the subject light beam reflected by the main mirror 13 when the main mirror 13 and the sub mirror 14 are in the mirror down position, that is, the observation position. The finder unit 4 includes a focusing screen 17 that is disposed at a position optically equivalent to the light receiving surface of the image sensor 16 with respect to the photographic lens, and is configured to form a subject image. A pentaprism 18 for converting the subject image formed on the screen 17 into an erect image, and an eyepiece optical system 19 for enlarging the optical image from the pentaprism 18 and guiding it to the eyes of the observer. It is prepared for.

  The distance measuring unit 5 is disposed on the optical path of the subject light beam reflected by the sub mirror 14 when the main mirror 13 and the sub mirror 14 are at the observation position. The distance measuring unit 5 includes a condenser lens 21, a first mirror 22, a second mirror 23, a separator lens 24, and a distance sensor 25, and performs distance measurement for so-called TTL phase difference AF. It is structured as a thing.

  A display unit 6 including a color liquid crystal display element and the like is disposed on the back side of the camera body 1 that is further rearward of the imaging unit 3.

  In addition, a strobe unit 7 for irradiating the subject with illumination light is disposed above the pentaprism 18 so as to pop up when in use and be housed in the camera body 1 when not in use.

  Next, a detailed configuration of the mirror device 2 will be described with reference to FIGS.

  As shown in FIG. 4, the main mirror 13 is held by a main mirror holding frame 41 and constitutes a main mirror unit. Further, the sub mirror 14 is held by a sub mirror holding frame 61 to constitute a sub mirror unit.

  The main mirror holding frame 41 has a pair of rotating shaft portions 43L and 43R projecting in the left-right direction on the main mirror rotating shaft 41a, and the pair of rotating shaft portions 43L and 43R are provided on the mirror box 12. It is rotatably supported by a pair of bearing portions 51L and 51R provided on the left wall surface portion 12L and the right wall surface portion 12R.

  The main mirror holding frame 41 has a pair of support shaft portions 46 protruding from the sub mirror rotation shaft 61 a, and the support shaft portions 46 have bearing hole portions 62 provided in the sub mirror holding frame 61. Are fitted. Thus, the sub mirror holding frame 61 is supported on the back side of the main mirror holding frame 41 so as to be rotatable around the support shaft portion 46, that is, around the sub mirror rotation shaft 61a.

  Further, as described above, the main mirror holding frame 41 is provided with an opening 42 which is a through hole having an octagonal shape, for example. The main mirror 13 is at least partially configured as a half mirror.

  In the present embodiment, on the right wall surface 12R of the mirror box 12, a main mirror stopper 33, which is a first stopper for positioning the lower end of the main mirror holding frame 41 in the mirror down position, and the mirror A sub mirror positioning stopper 34 for positioning the descending lower end side of the sub mirror holding frame 61 in the down position is protruded.

  When the main mirror holding frame 41 is lowered and the stopper abutting portion 45 provided on the right end side of the main mirror holding frame 41 is in contact with the main mirror stopper 33, as shown in FIG. Positioned at the down position (observation position).

  Similarly, the sub mirror holding frame 61 that rotates in a direction away from the main mirror holding frame 41 in conjunction with the lowering of the main mirror holding frame 41 is in contact with the right stopper provided on the right end side of the sub mirror holding frame 61. When the portion 64 contacts the sub mirror positioning stopper 34, the position when the mirror is lowered is determined as shown in FIG.

  That is, the state shown in FIG. 2 is a state where the mirror is down and no force is applied to the mirror device, that is, a state of the static mirror device when observing with the finder.

  On the other hand, on the left wall surface portion 12L of the mirror box 12, as shown in FIG. 5, the main mirror 13 is provided on the left end side of the sub mirror holding frame 61 in a state where the main mirror 13 is positioned at the mirror down position (observation position). A second stopper made of synthetic resin integral with the side wall surface portion at a position where the sub mirror holding frame 61 is separated from the main mirror holding frame 41 by a predetermined distance in a non-contact manner with respect to the left stopper abutting portion 65. A sub-mirror buffer stopper 35 is provided.

  The sub mirror buffering stopper 35 has a surface facing the left stopper abutting portion 65 of the sub mirror holding frame 61, that is, a front surface, a low-resilience resin or urethane foam material excellent in shock absorption, such as sorbosein (registered trademark). It is even better if it is made of a buffer material (buffer means, buffer member) which is an elastic body made of or the like.

  Although not shown in the figure, the location where the main mirror holding frame 41 and the upper wall surface of the mirror box 12 abut at the mirror up position and the location where the main mirror holding frame 41 and the sub mirror holding frame 61 abut are not shown. A shock-absorbing material made of an elastic body made of low-resilience resin or urethane foam excellent in shock absorption, such as sorbosein (registered trademark), is disposed.

  Next, the configuration of the bearing portion 51R that supports the rotation shaft portion 43R on the right side of the main mirror holding frame 41 in the mirror device of the present embodiment will be described with reference to FIG.

  The bearing portion 51R provided on the right side surface portion 12R of the mirror box 12 is a bearing portion that elastically supports the rotation shaft portion 43R on the right side of the main mirror holding frame 41. The bearing portion 51R has a bearing hole portion 52 having a V-shaped portion 52V whose opening shape is substantially V-shaped, and the rotating shaft portion 43R abuts the V-shaped portion 52V in the bearing hole portion 52. And a spring 53 biased in the direction.

  More specifically, the bearing hole portion 52 is a through hole formed in a direction substantially orthogonal to the right side surface portion 12R of the mirror box 12, and has a tapered V-shape that expands forward in the side surface portion. A portion 52V is formed.

  The rotating shaft 43R inserted in the bearing hole 52 is moved backward, that is, toward the valley of the V-shaped portion 52V by a spring 53 which is a torsion spring fixed to the mirror box 12 by spring fixing portions 54 and 55. Be energized. The spring 53 may be another type of spring such as a leaf spring, or may be an elastic member such as rubber.

  Due to the urging force of the spring 53, the rotating shaft portion 43R having a cylindrical shape contacts the V-shaped portion 52V and is positioned without backlash. However, a force that exceeds the urging force of the spring 53 is applied to the rotating shaft portion 43R. In this case, the rotation shaft portion 43R can be displaced in the direction in which the V-shaped portion 52V expands, that is, substantially forward. Needless to say, when the force applied to the rotation shaft portion 43R disappears, the rotation shaft portion 43R is positioned again by the biasing force of the spring 53.

  The movement of the mirror device during the mirror down operation in the single-lens reflex camera of the present embodiment described above will be described below. In the above-described mirror device, in a dynamic state in which the main mirror 13 is moved to the mirror down position (observation position), the movable part of the mirror device is the main mirror stopper 33 and the sub mirror positioning stopper provided at the right end of the mirror box 12. 34 abuts.

At this time, since the movable part of the mirror device has kinetic energy in the direction in which the main mirror 13 descends, the movable part of the mirror device includes the main mirror stopper 33 or the sub mirror positioning stopper 34 and the mirror box. The force of the direction rotated around the axis which connects the bearing part 51L provided in the left end of 12 acts.

  As a result, a force is exerted on the bearing portion 51R provided at the right end of the mirror box 12 in a direction to push the rotating shaft portion 43R substantially forward, so that the movement of the movable portion of the mirror device is caused by deforming the spring 53. Energy is reduced.

  Further, since the rotation shaft 43R moves forward by the deformation of the spring 53, the left stopper contact portion 65 of the sub mirror holding frame 61 contacts the sub mirror buffer stopper 35. Since the sub-mirror buffer stopper 35 is made of a buffer material, the kinetic energy of the movable part of the mirror device is further reduced.

  In other words, the mirror device of the single-lens reflex camera of this embodiment elastically supports the movable part of the mirror, and further, the movable part of the mirror becomes a cushioning material after the support part is elastically deformed by the kinetic energy when the mirror is down. It is comprised so that it may contact | abut.

  Therefore, according to the present embodiment, the kinetic energy during the mirror down operation can be efficiently reduced, and the bounce of the submirror can be reduced.

  In addition, although the movable part of the mirror device of the single-lens reflex camera described above is configured only to rotate around a predetermined axis, it is a mirror device that performs a motion other than rotation using a cam, a link mechanism, or the like. Even if it exists, this invention is applicable.

  Further, although the sub mirror buffering stopper 35 that does not contact in the static state is disclosed, similarly, it does not contact the main mirror holding frame 41 in the static state, and the main mirror holding frame 41 in the dynamic state. A main mirror buffering stopper as a second stopper that abuts may be provided on the side surface of the mirror box 12.

  The bearing portion 51R is not always necessary. This is because, in the dynamic state, deformation of the main mirror holding frame 41 and deformation of the sub mirror holding frame 61 also occur. Therefore, the deformation may be used to make contact with the buffer stopper.

  Note that the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit or idea of the invention which can be read from the claims and the entire specification. The mirror device of the reflex camera is also included in the technical scope of the present invention.

  The single-lens reflex camera according to the present invention is not limited to the form of the interchangeable lens digital camera described in the above-described embodiment, but is a single-lens reflex camera that performs photographing with a film, or a photographing lens and a main body. Needless to say, it may be a single-lens reflex camera.

It is a figure which shows schematic structure of the main body of a single-lens reflex camera. It is the figure which looked at the mirror apparatus in a mirror down position from the side. It is the figure which looked at the mirror apparatus in a mirror up position from the side. It is the figure which looked at the mirror apparatus in a mirror down position from the lower side. It is the perspective view which looked at the mirror apparatus in a mirror down position from the back side. It is a figure which shows the positional relationship of the mirror and buffer stopper which are in a mirror down position statically. It is a figure which shows the structure of a bearing part.

Explanation of symbols

2 mirror device, 12 mirror box, 13 main mirror, 14 sub mirror, 33 main mirror stopper, 34 sub mirror positioning stopper, 35 sub mirror buffer stopper, 41 main mirror holding frame, 43 rotating shaft portion, 44 cushioning material, 51 bearing portion, 61 Sub mirror holding frame

Claims (2)

A single-lens reflex camera,
A main mirror holding frame that supports a main mirror that moves between a first position and a second position different from the first position;
A mirror box having a pair of side walls to rotatably support the main mirror holding frame;
To fit position-decided the main mirror holding frame in the first position, the first so as to abut with the main mirror holding frame in position, a first stopper provided on one of the pair of sidewall portions When,
In a state where the main mirror holding frame is statically positioned by the first stopper, the main mirror holding frame is at a position separated from the main mirror holding frame, and the main mirror holding frame is moved from the second position to the first position. A main mirror buffering stopper provided on the other of the pair of side wall surface portions so as to abut on the main mirror holding frame deformed by abutting against the first stopper,
Single-lens reflex camera which is characterized in that it has a. The main mirror holding frame moves between the first position where the main mirror reflects the subject light beam to the observation optical system and the second position where the main mirror retracts from the subject light beam. single-lens reflex camera according to claim 1, characterized by.

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