JP2012063452A - Impact absorption mechanism for movable mirror of camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impact absorption mechanism for a movable mirror of a camera, which has a low number of components and a simple structure, contributing downsizing and cost reduction of the camera.SOLUTION: An impact absorption mechanism for a movable mirror of a camera, comprises: a movable mirror supported such that it can rotate between a finder light guiding position inserted on a photographing optical path and a retreat position out of the photographing optical path; a mirror advance absorbing member which, when the movable mirror rotates from the retreat position to the finder light guiding position, comes into abutting contact with the movable mirror and is moved by being pushed, and which absorbs an impact on the movable mirror; and a mirror retreat absorbing member which, when the movable mirror rotates from the finder light guiding position to the retreat position, comes into abutting contact with the movable mirror and is moved by being pushed, and which absorbs an impact on the movable mirror. The impact absorption mechanism is configured such that, when the movable mirror is in the finder light guiding position, the mirror retreat absorbing member holds the mirror advance absorbing member in a position not abutting on the movable mirror.

Description

  The present invention relates to a drive device for a movable mirror provided in a single-lens reflex camera, and more particularly to an impact absorbing mechanism for the movable mirror.

  Inside the single-lens reflex camera, a finder light guide position (down position) that is inserted in the photographic optical path and reflects the subject light to the finder optical system, and a retracted position that evacuates from the photographic optical path and passes the subject light to the shutter side. A movable mirror (quick return mirror) that can be turned up and down is provided at (up position). The movable mirror is in contact with a positioning member provided in the mirror box and its rotation is restricted, but bounce (vibration) is generated by an impact when it comes into contact with the positioning member. When the movable mirror bounces, the observation image of the finder is not stable and adversely affects the observation performance. Also, with a camera that uses a movable mirror to direct the subject light to a distance measuring sensor or a photometric sensor, accurate distance measurement or photometry cannot be performed while the movable mirror is bouncing. Copy performance is limited. For this reason, there has been proposed an impact absorbing mechanism that absorbs an impact when the movable mirror rotates and suppresses a bounce.

JP 2000-131755 A

  As a shock absorbing mechanism for a movable mirror, a type in which the movable mirror is brought into contact with an elastic member, a type in which the movable mirror is brought into contact with a moving member that is moved and urged by an urging member, and the like are known. However, high accuracy of the movable mirror is required at the finder light guide position that directly affects the observation performance of the finder and at the retracted position where the exposure operation is performed. The impact absorbing mechanism is required to be configured so as not to interfere with the positioning by the positioning member. In other words, the impact absorbing mechanism of the movable mirror in the camera is not only to suppress the bounce when the mirror is rotated, but when the movable mirror reaches the rotating end, it is required not to disturb the positioning, and the structure is It was easy to make it complicated.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a movable mirror shock absorbing mechanism that contributes to downsizing and cost reduction of a camera with a small number of parts and a simple structure.

  The first aspect of the present invention includes a finder light guide position that is positioned on the photographing optical path and reflects the subject light to the observation optical system, and a retreat position that is retracted from the photographing optical path and allows the subject light to pass to the imaging light receiving medium side. And a movable mirror that is pivotally supported between the movable mirror and the movable mirror, and when the movable mirror rotates from the retracted position to the finder light guide position, the movable mirror contacts and is pressed against the movable mirror to absorb the shock to the movable mirror. Movable mirror shock absorption of a camera having a buffer member and a mirror retracting buffer member that is pressed against the movable mirror when the movable mirror rotates from the finder light guide position to the retracted position and absorbs the impact to the movable mirror When the movable mirror is in the finder light guide position, the mirror advancement buffer member holds the mirror advancement buffer member in a non-contact position with respect to the movable mirror. It is characterized in that.

  As one form of this invention, it is preferable to comprise as follows. First, the mirror advancing buffer member is a rotating member that can rotate about an axis substantially parallel to the rotating axis of the movable mirror, and is biased to rotate in the direction of contact with the movable mirror by the first biasing member. To do. The mirror retracting buffer member can move linearly along a plane substantially orthogonal to the rotation axis of the mirror advance buffer member, and is moved and urged by the second urging member in the direction of contact with the movable mirror. When the movable mirror rotates from the retracted position to the finder light guiding position, the mirror advancement buffer member is pressed against the urging force of the first urging member, and the movable mirror rotates from the finder light guiding position to the retracted position. When doing so, the mirror retracting buffer member is pressed against the biasing force of the second biasing member. The mirror retracting buffer member moves forward on the rotation trajectory of the mirror advancement buffer member when it is at the moving end in the urging direction by the second urging member, and restricts its rotation range. A rotation restricting portion that retreats from the rotation locus of the mirror advancing buffer member by being pressed and moved in a direction opposite to the urging direction of the second urging member is provided.

  The mirror advancing buffer member includes a rotation restricting surface that comes into contact with the rotation restricting portion when receiving the rotation restriction by the mirror retracting buffer member, and is located on the outer diameter side of the rotation restricting surface, and the mirror retracting buffer member In a contact state with the rotation restricting portion, a rotation allowing surface that allows the mirror advancing buffer member to rotate while restricting the movement of the mirror retracting buffer member in the urging direction by the second urging member is formed. It is preferable to do.

  The mirror advance buffer member and the mirror retract buffer member are preferably supported on the side of the mirror box that supports the movable mirror inside. In this case, a protruding contact portion that is provided on each of the mirror advancing buffer member and the mirror retracting buffer member and that can contact the movable mirror protrudes from one of a pair of opposing inner wall surfaces of the mirror box that is located across the movable mirror. And a mirror positioning portion for determining the finder light guide position of the movable mirror is projected from the other side. When the movable mirror contacts the mirror positioning portion and is held at the finder light guide position, the mirror advance buffer member contacts the rotation restricting portion of the mirror retract buffer member, and the protruding contact portion is moved away from the movable mirror. It is held at a position to be separated.

  The mirror box includes a first restricting portion that determines a rotation end of the mirror advancement buffer member in the biasing direction by the first biasing member, and a mirror retracting buffer member in the biasing direction by the second biasing member. It is preferable to form a second restricting portion that determines the moving end of the second moving portion.

  The first urging member may be constituted by a torsion spring that engages with the mirror box and the mirror advance buffer member, and the second urging member may be constituted by a tension spring that engages with the mirror box and the mirror retracting buffer member. . Alternatively, the second urging member may be constituted by a torsion spring that engages with the mirror box and the mirror retracting buffer member.

  The second aspect of the present invention includes a finder light guide position that is located on the photographing optical path and reflects the subject light to the observation optical system, and a retreat position that is retracted from the photographing optical path and allows the subject light to pass to the imaging light receiving medium side. A movable mirror that is rotatably supported between the movable mirror and a movable mirror that is pressed against the movable mirror when the movable mirror rotates in one direction between the retracted position and the finder light guide position. The first buffer member that absorbs shock to the movable mirror, and when the movable mirror rotates in the other direction between the retracted position and the finder light guide position, the movable mirror abuts against the movable mirror to be pressed and moved to absorb the shock to the movable mirror. A movable mirror shock absorbing mechanism of a camera having a second buffer member, and an engagement mechanism provided on the first buffer member and the second buffer member, wherein at least one of the first buffer member and the second buffer member One is a movable mirror An over-movement region that does not contact the movable mirror before the buffer movement region that is pressed and moved in contact with the movable mirror; and the engagement mechanism is an over-movement of the first buffer member and the second buffer member. When one buffer member having a region is pressed and moved by a movable mirror, the other buffer member is engaged, and the one buffer member is held in the over-moving region. It can be arbitrarily selected whether the buffer member having the over movement area is either the first buffer member or the second buffer member or both.

  For example, it is assumed that at least the first buffer member has an over-moving region, and the engagement mechanism biases the first buffer member and the second buffer member in directions opposite to the pressing movement direction by the movable mirror, respectively. Urging member, an engagement surface portion provided on the first buffer member and directed in the urging direction by the first urging member, provided on the second buffer member, and the first buffer member according to the movement of the second buffer member. It is good to provide the movement control part which advances / retreats on the movement locus | trajectory of the engaging surface part of a buffer member. When the second buffer member is moved in the biasing direction of the second biasing member, the movement restricting portion provided on the second buffer member is positioned on the movement locus of the engagement surface portion of the first buffer member. The engagement surface portion and the movement restricting portion are brought into contact with each other by the urging force of the first urging member to hold the first buffer member in the over movement region, and the second buffer member is applied to the urging force of the second urging member. It is preferable that the movement restricting portion retracts from the movement locus of the engagement surface portion of the first buffer member when pressed against the movable mirror.

  According to the first aspect of the present invention, the mirror advancing buffer member that absorbs shock when the movable mirror rotates to the finder light guide position is movable when the movable mirror reaches the finder light guide position. Therefore, the finder light guide position of the movable mirror can be set with high accuracy without being influenced by the mirror advance buffer member. Since the means for holding the mirror advancement buffer member at the non-abutting position with the movable mirror also serves as a mirror retracting buffer member that absorbs shock when the movable mirror rotates to the retracted position, the movable mirror The number of parts in the shock absorbing mechanism is small, the structure is simple, and the downsizing and cost reduction of the camera can be achieved.

  According to the second aspect of the present invention, at least one of the two buffer members that absorbs the shock when the movable mirror rotates to the finder light guide position and the retracted position does not contact the movable mirror with the other. Since it also functions as a holding means for holding in the over-moving range, the movable mirror can be positioned with high accuracy without being affected by the buffer member, and the structure is simplified by reducing the number of parts in the movable mirror shock absorbing mechanism. Can be.

It is a figure which shows the outline of the optical system of the single-lens reflex camera to which this invention is applied. It is a front perspective view of the mirror box in a mirror down state. It is a front perspective view of the mirror box in a mirror up state. It is a back perspective view of a mirror box in a mirror down state. It is a back perspective view of a mirror box in a mirror down state. It is a back perspective view of a mirror box in a mirror up state. It is a perspective view of the mirror buffer mechanism in a state where the contact portion of the mirror sheet is in contact with the buffer dowel of the down absorption lever. It is a perspective view of the mirror buffer mechanism in a state where the contact portion of the mirror sheet is in contact with the buffer dowel of the up-absorbing lever. It is a left view of the mirror box of a state where the presser plate is removed and the mirror buffer mechanism is exposed. It is a side view of the mirror buffer mechanism in the mirror-down state. It is a side view of the mirror buffer mechanism in a state in which the movable mirror is rotating from the down position to the up position. It is a side view of the mirror buffer mechanism in the mirror up state. It is a side view of the mirror buffer mechanism in a state in which the movable mirror is rotating from the up position to the down position. FIG. 10 is a side view of the mirror buffer mechanism in a state where the movable mirror completes the rotation from the up position to the down position, and the down absorption lever is rotated to the over position before the rotation restriction position by the up absorption lever. It is a side view which shows the mirror down state of the mirror buffer mechanism of the form which comprised the up absorption spring which urges | biases an up absorption lever with the torsion spring. It is a side view which shows the mirror up state of the mirror buffer mechanism of the form which comprised the up absorption spring which urges | biases an up absorption lever with the torsion spring.

  A single-lens reflex camera (hereinafter referred to as a camera) 10 shown in FIG. 1 has a lens mount 13 for attaching and detaching an interchangeable lens barrel 12 on the front surface of a camera body 11, and a mirror box 14 is provided on the inside thereof. .

  A movable mirror (quick return mirror) 15 is provided in the mirror box 14. The movable mirror 15 has a structure in which the main mirror 15 a is fixedly supported on the mirror sheet 16, and the sub mirror 17 is rotatably supported on the back side of the mirror sheet 16, and protrudes on both sides of the mirror sheet 16. A pair of mirror sheet hinges 16 x are pivotally supported on both side walls of the mirror box 14. A focal plane shutter (hereinafter referred to as shutter) 18 is provided behind the movable mirror 15, and an image sensor (imaging light receiving medium) 19 is provided behind the shutter 18. Note that the camera 10 of the present embodiment is a digital camera that uses the image sensor 19 as an imaging light-receiving medium, but the present invention can also be applied to a camera that uses a silver salt film as the imaging light-receiving medium.

  The movable mirror 15 is inclined down at an angle of about 45 degrees on the photographing optical path from the photographing lens 12a in the lens barrel 12 to the image sensor 19 with the mirror sheet hinge 16x as an axis (finder light guide position: 1 between the solid line in FIG. 1, FIG. 2, FIG. 4, FIG. 5, and FIG. 10) and the up position retracted upward from the imaging optical path (retracted position: two-dot chain line in FIG. 1, FIG. 3, FIG. Is reciprocally rotated. As shown in FIGS. 4 and 6, a down positioning dowel (mirror positioning portion) 20 protrudes from one inner surface of both side walls of the mirror box 14 positioned with the movable mirror 15 interposed therebetween. On the other hand, the down position of the movable mirror 15 is determined by bringing a stopper 16a (FIGS. 7 and 8) provided on one side of the mirror sheet 16 into contact. The down positioning dowel 20 can finely adjust the mounting position with respect to the mirror box 14. Also, an upper stopper 21 is provided in the mirror box 14 so that the upper surface of the mirror sheet 16 can come into contact when the movable mirror 15 is rotated to the up position. A finder optical system 22 composed of a pentaprism, an eyepiece, or the like is provided above the movable mirror 15.

  When the movable mirror 15 is in the down position, subject light that enters the mirror box 14 through the photographing lens 12a in the lens barrel 12 with the lens barrel 12 mounted on the lens mount 13 is the main mirror of the movable mirror 15. The object image can be observed through the finder window 22a on the rear side of the camera body 11 after being reflected by the lens 15a and entering the finder optical system 22. In this state, photometry can be performed by the photometry unit 23 provided behind the pentaprism constituting the finder optical system 22. In the down position of the movable mirror 15, the sub mirror 17 protrudes obliquely downward with respect to the mirror sheet 16, and part of the subject light is guided to the distance measuring unit 24 below the mirror box 14 by the sub mirror 17, The distance can be detected. On the other hand, when the movable mirror 15 is in the up position, the subject light incident into the mirror box 14 through the photographing lens 12a is not reflected by the movable mirror 15 but proceeds to the shutter 18 side, and the shutter 18 is opened to open the image sensor 19. Light can be incident on the light receiving surface. At the up position of the movable mirror 15, the sub mirror 17 is stored on the back side of the mirror sheet 16. The LCD monitor 25 provided on the rear surface of the camera body 11 can display an electronic image of the subject obtained by the image sensor 19 and various types of information other than the electronic image.

  As shown in FIG. 5, a mirror drive mechanism 30 that moves the movable mirror 15 up and down is provided on one side of the mirror box 14 (on the left side when viewed from the front). The mirror drive mechanism 30 includes a motor 31, a reduction gear train 32 that transmits a drive force of the motor 31, a cam gear 33 that receives a rotational drive force from the reduction gear train 32 via a planetary gear mechanism, and a cam gear 33. A mirror drive lever 34 whose rotation position is controlled is provided. The mirror drive lever 34 is supported by the mirror box 14 so as to be reciprocally rotatable about an axis 34x substantially parallel to the axis of the mirror sheet hinge 16x, and holds a mirror sheet boss 16b provided on the side of the mirror sheet 16. is doing. The holding portion by the mirror driving lever 34 presses the mirror sheet boss 16b downward to rotate the movable mirror 15 toward the down position, and presses the mirror sheet boss 16b upward to move the movable mirror 15 to the up position. Rotate toward The mirror drive lever 34 is urged to rotate in a direction to press the movable mirror 15 to the down position, and when the cam gear 33 is in a specific rotation position, a mirror control cam (peripheral cam) formed on the cam gear 33. Thus, the mirror drive lever 34 is pressed and rotated in the mirror up direction against the urging force. Specifically, the cam gear 33 is a one-rotation cam gear that is rotated only in one direction from the initial position. When the cam gear 33 is in the initial position, the mirror control cam of the cam gear 33 does not press the mirror drive lever 34, and the mirror drive. The movable mirror 15 is held in the down position by the urging force acting on the lever 34. When the cam gear 33 is rotated from the initial position to the middle, the mirror control cam of the cam gear 33 presses and rotates the mirror drive lever 34, and the mirror drive lever 34 rotates the movable mirror 15 to the up position. From this midway position until the cam gear 33 returns to the initial position, the mirror control cam of the cam gear 33 releases the pressure on the mirror drive lever 34, and the movable mirror 15 is returned to the down position.

  A shutter charge lever 35 for charging the shutter 18 is further provided on one side of the mirror box 14. The cam gear 33 has a shutter charge cam that controls the operation of the shutter charge lever 35 in addition to the above-described mirror drive cam, and rotates the shutter charge lever 35 reciprocally by rotating once from the initial position to charge the shutter. Let it be done. Since the shutter charge mechanism is not related to the features of the present invention, detailed description thereof is omitted.

  The other side of the mirror box 14 (the side on the right side when viewed from the front) absorbs an impact when the movable mirror 15 rotates to the down position and the up position, thereby suppressing the bounce (vibration) of the movable mirror 15. A mirror buffer mechanism (movable mirror shock absorbing mechanism) 40 is provided. The mirror buffer mechanism 40 includes a down absorption lever (mirror advance buffer member, buffer member) 41, a down absorption spring (first urging member, engagement mechanism) 42, and an up absorption lever (mirror retract buffer member, buffer member) 43. And an up-absorbing spring (second urging member, engagement mechanism) 44, each of which is held so as not to fall off by a pressing plate 45 (FIG. 4) fixed to the side of the mirror box 14. ing.

  The down-absorbing lever 41 protrudes from the mirror box 14 and is rotatably supported by a shaft 41x substantially parallel to the mirror seat hinge 16x. The down absorption lever 41 has a substantially sector shape centered on the shaft 41x, and has a buffering dowel (projection contact portion) 41a that projects toward the inner side of the mirror box 14 at a position close to the peripheral portion of the fan. A rotation restricting surface (engagement mechanism, engagement surface portion) 41b extending in the radial direction is provided near the shaft 41x. Further, following the rotation restricting surface 41b, a rotation permitting surface 41c is formed which is positioned on the outer diameter side of the rotation restricting surface 41b and has an arc shape centering on the shaft 41x. The mirror box 14 is formed with an arc-shaped through hole 14a centering on an axis 41x, and the buffer dowel 41a of the down absorption lever 41 is inserted into the through hole 14a and protrudes into the mirror box 14. (See FIG. 2, FIG. 3, FIG. 5 and FIG. 9). The buffer dowel 41a is located on the movement locus of the buffer contact portion 16c provided on the side portion near the front end portion of the mirror sheet 16 (on the rotation locus of the movable mirror 15 around the mirror sheet hinge 16x). Thus, it is possible to contact the lower surface side of the buffer contact portion 16c.

  The down absorption spring 42 is associated with a coil portion 42 a surrounding the shaft 41 x, a spring arm portion 42 b that engages with a spring hook portion 14 b formed on the side surface of the mirror box 14, and a spring hook portion 41 d formed on the down absorption lever 41. This is a torsion spring having a mating spring arm portion 42c, and urges the down absorption lever 41 to rotate clockwise in FIGS. The urging direction of the down-absorbing lever 41 by the down-absorbing spring 42 is a direction in which the buffer dowel 41a approaches (contacts) the buffer contact portion 16c of the mirror sheet 16, and the urging direction of the down-absorbing lever 41 is reduced. A rotation restricting protrusion (first restricting portion) 14 c that defines the turning end of the absorbing lever 41 is provided on the side surface of the mirror box 14. The rotation end of the down absorption lever 41 that is in contact with the rotation restricting protrusion 14c is referred to as a buffer standby position. The down absorption lever 41 can rotate in a direction away from the rotation restricting projection 14c against the urging force of the down absorption spring 42 with the buffer standby position as one rotation end. The down absorption lever 41 is pressed by the buffer contact portion 16c of the movable mirror 15 (mirror sheet 16) rotating in the down position direction from the buffer standby position shown in FIGS. 12 and 13 to a predetermined position. It is rotated against the urging force of the down absorption spring 42. This predetermined position is a position corresponding to the down position of the movable mirror 15. When the movable mirror 15 reaches the down position, the stopper portion 16a abuts on the down positioning dowel 20 and further rotation is restricted. Therefore, the pressing force from the buffer contact portion 16c does not reach the down absorption lever 41 any more. The rotation range of the down absorption lever 41 that receives the pressing movement force by the movable mirror 15 is called a buffer movement area. The down absorption lever 41 is further rotatable to an over movement area ahead of the buffer movement area. FIGS. 10 and 14 show a state in which the down absorption lever 41 is in the over movement range, and the movable mirror 15 is in contact with the down positioning dowel 20 and is prevented from rotating beyond the down position. On the other hand, the down absorption lever 41 separates the buffer dowel 41a from the buffer contact portion 16c of the mirror sheet 16, and the contact relationship with the movable mirror 15 is released.

  The up-absorption lever 43 has two guide holes 43a and guide holes 43b through which two guide pins 14d and upper and lower guide pins 14d projecting on the side surface of the mirror box 14 are inserted. By receiving the guidance of the guide pins 14d and 14e through the holes 43a and 43b, the holes 43a and 43b are supported so as to be able to move straight up and down. The linear movement direction of the up-absorbing lever 43 is set within a plane substantially orthogonal to the axis of the rotation shaft 41x of the down-absorbing lever 41. In other words, the down absorption lever 41 and the up absorption lever 43 are supported so as to be rotatable and movable along planes parallel to each other. In the vicinity of the upper end of the up-absorbing lever 43, there is a buffer dowel (projecting contact portion) 43c that protrudes inward of the mirror box 14, and a spring hook 43d is provided in the vicinity of the lower end. Yes. The mirror box 14 is formed with a through hole 14f which is a long hole in the vertical direction, and the buffer dowel 43c of the up-absorbing lever 43 is inserted into the through hole 14f and protrudes into the mirror box 14 ( (See FIGS. 2, 3 and 9). The buffer dowel 43c is located on the movement locus of the buffer contact portion 16c of the mirror sheet 16 (on the rotation locus of the movable mirror 15 around the mirror sheet hinge 16x), and the upper surface of the buffer contact portion 16c. It can come into contact with the side. On the side of the up-absorbing lever 43, a rotation restricting arm (rotation restricting portion, engagement mechanism, movement restricting portion) 43e protrudes. The rotation restricting arm 43e protrudes in a direction substantially orthogonal to the vertical direction that is the moving direction of the up-absorbing lever 43, and has a hook-like shape in which the vicinity of the tip is bent downward.

  The up absorption spring 44 is a tension spring, one end of which is hung on a spring hook 43d formed on the up absorption lever 43, and the other end is hung on a spring hook 14g formed on the side surface of the mirror box 14. The absorption lever 43 is urged to move downward. The urging direction of the up absorption lever 43 by the up absorption spring 44 is a direction in which the buffer dowel 43c approaches (contacts) the buffer contact portion 16c of the mirror sheet 16, and the up absorption lever 43 is a guide. By bringing the upper end portion of the guide hole 43b into contact with the pin 14e, the movement of the up absorption spring 44 in the urging direction is restricted. The moving end of the up absorption lever 43 in the urging direction (downward) of the up absorption spring 44 is referred to as a buffer standby position. At the buffer standby position of the up absorption lever 43, the rotation restriction arm 43e advances on the rotation locus of the rotation restriction surface 41b around the shaft 41x of the down absorption lever 41, and with respect to the rotation restriction surface 41b. Thus, the rotation of the down-absorbing lever 41 in the urging direction of the down-absorbing spring 42 is regulated by bringing the side surface of the rotation-limiting arm 43e into contact (FIGS. 10 and 11). More specifically, the side of the rotation restricting surface 41b of the down absorption lever 41 and the side surface of the rotation restricting arm 43e of the up absorption lever 43 can be opposed to each other because the up absorption lever 43 is in the buffer standby position. And it is the state which satisfy | filled the relationship that the down absorption lever 41 exists in the above-mentioned over movement range. Therefore, when the rotation of the up absorbing lever 43 is restricted by the contact of the rotation restricting surface 41b with the rotation restricting arm 43e, the down absorbing lever 41 moves the buffer dowel 41a from the buffer abutting portion 16c of the mirror sheet 16. It is held in the over movement area to be separated. On the other hand, in a state where the end of the rotation restricting arm 43e deviates from the rotation locus of the rotation restricting surface 41b (FIG. 12), the holding in the over moving region with respect to the down absorbing lever 41 is released, The down absorption spring 42 can be rotated in the urging direction (buffer standby position). Further, in a state where the end of the rotation restricting arm 43e is in contact with the rotation permitting surface 41c (FIG. 13), the down absorbing lever 41 is brought into sliding contact with the rotation restricting arm 43e. Is allowed to rotate.

  The operation of the mirror buffer mechanism 40 will be described with reference to FIG. FIG. 10 shows a state where the movable mirror 15 is in the down position. At this time, the mirror sheet boss 16 b is pressed downward by the mirror drive lever 34 constituting the mirror drive mechanism 30, and the movable mirror 15 is held in the down position by the stopper portion 16 a of the mirror sheet 16 contacting the down positioning dowel 20. Has been. The up-absorbing lever 43 is held at the buffer standby position by the urging force of the up-absorbing spring 44, and the urging direction (clockwise direction) of the down-absorbing spring 42 by bringing the rotation restricting arm 43e into contact with the rotation restricting surface 41b. The rotation of the down-absorption lever 41 to) is restricted. The down absorption lever 41 is in an over-moving region in which the buffer dowel 41a is separated from the buffer contact portion 16c of the mirror sheet 16, and the down absorption lever 41 is not involved in the positioning of the mirror sheet 16, and the down positioning dowel 41 The positioning of the mirror sheet 16 by 20 is not hindered. More specifically, in FIG. 10 in which the mirror sheet 16 is viewed from the side, the stopper portion 16a provided on one side and the buffer contact portion 16c provided on the other side are shown as being in the same position. ing. The down absorption lever 41 whose rotation is restricted by the up absorption lever 43 positions the buffer dowel 41a at a position advanced in the mirror down direction (counterclockwise direction in FIG. 10) from the down positioning dowel 20. . Due to the relative positional relationship between the down positioning dowel 20 and the buffer dowel 41a, the down positioning dowel 20 is in contact with the stopper portion 16a, and the buffer dowel 41a is not in contact with the buffer contact portion 16c (over movement range). It is done.

  When the movable mirror 15 is rotated from the down position to the up position by the mirror drive lever 34 of the mirror drive mechanism 30, the upper surface of the buffer contact portion 16c of the mirror sheet 16 is eventually raised as shown in FIG. It contacts the buffer dowel 43c of the absorption lever 43. At the time of FIG. 11, the movable mirror 15 has not reached the up position, and the buffer contact portion 16c of the mirror sheet 16 pushes up the buffer dowel 43c while the movable mirror 15 rotates to the up position shown in FIG. Thus, the up absorption lever 43 is pushed and moved upward from the buffer standby position against the urging force of the up absorption spring 44. That is, the load of the up absorption spring 44 acts on the rotation of the movable mirror 15, and the movable mirror 15 reaches the up position while being buffered by the up absorption lever 43 and the up absorption spring 44. Thereby, the occurrence of bounce (vibration) of the movable mirror 15 when rotating from the down position to the up position is reduced. Specifically, the occurrence time of bounce is shortened and the number of times of bounce is reduced. At the up position of the movable mirror 15, the upper surface of the mirror sheet 16 comes into contact with the upper stopper 21, and further upward rotation is restricted (FIG. 1). The up absorption lever 43 is movable upward to a position where the lower end of the guide hole 43a contacts the guide pin 14d. However, the movable mirror 15 is moved before the up absorption lever 43 reaches the upper movement end. It comes into contact with the upper stopper 21. That is, the up absorption lever 43 is also stopped at the up position by the upper stopper 21 before the buffer movement area where the buffer dowel 43c is pressed by the buffer contact portion 16c of the movable mirror 15 (mirror sheet 16). An over-moving region is provided in which the buffer dowel 43c can be separated from the buffer contact portion 16c of the movable mirror 15.

  When the movable mirror 15 rotates to the up position, if the up absorption lever 43 is pushed upward from the buffer standby position by the buffer contact portion 16c of the mirror sheet 16, the rotation control arm 43e is rotated. Retreat upward from the turning trajectory of 41b. As a result, the rotation restriction on the down absorption lever 41 is released, and as shown in FIG. 12, the down absorption lever 41 is rotated to the buffer standby position in contact with the rotation restriction protrusion 14c by the urging force of the down absorption spring 42. Is done. When the down absorption lever 41 is at the buffer standby position, the buffer dowel 41a is located above the down positioning dowel 20, that is, a position (movable mirror 15 is moved in the clockwise direction in FIG. 12) of the movable mirror 15. When rotating to the down position, a position where the contact between the buffer contact portion 16c of the mirror sheet 16 and the buffer dowel 41a occurs before the contact between the stopper portion 16a of the mirror sheet 16 and the down positioning dowel 20 )It is in. Further, at the buffer standby position of the down absorption lever 41, the rotation allowing surface 41 c is positioned so as to be separated below the rotation restricting arm 43 e of the up absorption lever 43.

  When the movable mirror 15 is rotated from the up position to the down position by the mirror drive lever 34 of the mirror drive mechanism 30, the up absorption lever 43 follows the movement of the buffer contact portion 16c of the mirror sheet 16. It is moved downward toward the buffer standby position by the urging force of the up absorption spring 44. As shown in FIG. 13, when the up absorption lever 43 moves by a predetermined amount, the lower end portion of the rotation restricting arm 43e comes into contact with the rotation allowable surface 41c of the down absorption lever 41, and the downward movement of the up absorption lever 43 is halfway. Stopped at. Subsequently, when the movable mirror 15 approaches the down position, before the stopper portion 16a of the mirror sheet 16 comes into contact with the down positioning dowel 20, the buffer contact portion 16c of the mirror sheet 16 is moved as shown in FIG. It contacts the buffer dowel 41a of the down absorption lever 41. At this time, the down absorption lever 41 is held at the buffer standby position by the urging force of the down absorption spring 42, and the buffer sheet abuts against the mirror sheet 16 while the movable mirror 15 rotates to the down position shown in FIG. The portion 16c pushes down the buffer dowel 41a and rotates the down absorption lever 41 counterclockwise in FIG. 13 from the buffer standby position against the urging force of the down absorption spring 42. At this time, the down absorption lever 41 can be rotated without being restricted by the up absorption lever 43 by bringing the rotation allowance surface 41 c into sliding contact with the end of the rotation restriction arm 43 e. As a result, while the down absorption lever 41 is rotating in the buffer movement range starting from the buffer standby position, the load of the down absorption spring 42 acts on the rotation of the movable mirror 15, and the movable mirror 15 absorbs the down absorption. It reaches the down position while being buffered by the lever 41 and the down absorption spring 42. As a result, the occurrence of bounce (vibration) of the movable mirror 15 when rotating from the up position to the down position is reduced (the occurrence time of bounce is shortened and the number of bounces is reduced).

  FIG. 14 shows a state immediately after the movable mirror 15 is rotated to the down position. Similarly to FIG. 10, the stopper portion 16 a of the mirror sheet 16 contacts the down positioning dowel 20, and the rotation of the movable mirror 15 in the mirror down direction (counterclockwise direction in FIG. 14) is restricted. As a result of the down absorption lever 41 being pressed and rotated from the buffer standby position, the movement restriction due to the contact relationship between the rotation allowable surface 41 c and the rotation restriction arm 43 e is released, and the up absorption lever 43 is attached to the up absorption spring 44. It is moved downward to the buffer standby position by the force. Thereby, the rotation restricting arm 43e advances on the rotation locus of the rotation restricting surface 41b, and the rotation of the down absorption lever 41 to the buffer standby position (clockwise in FIG. 14) is restricted. Specifically, when the movable mirror 15 rotates to the down position, as shown in FIG. 14, the down absorption lever 41 exceeds the buffer movement range and the rotation restriction arm 43 e of the up absorption lever 43 restricts the rotation. The surface 41b is rotated by inertia to a position where the surface 41b is separated, that is, to an over movement range. Subsequently, the down absorption lever 41 returns to the position of FIG. 10 where the rotation restricting surface 41 b is brought into contact with the rotation restricting arm 43 e of the up absorption lever 43 by the urging force of the down absorption spring 42. As described above, not only FIG. 14 but also the position of the down-absorbing lever 41 in FIG. 10 is an over-moving region in which the buffer dowel 41 a is separated from the buffer contact portion 16 c of the mirror sheet 16. The position is determined by down positioning dowels 20. That is, when the movable mirror 15 rotates toward the down position, the down absorption lever 41 functions as a buffer member in a buffer movement area in which the buffer dowel 41a contacts the buffer contact portion 16c. In the state where the down position has been reached, the mirror sheet 16 is held at a non-contact position (over movement range), and positioning of the movable mirror 15 by the down positioning dowel 20 is not hindered.

  As described above, in the camera 10 of the present embodiment, when the movable mirror 15 rotates between the down position and the up position, the down absorption lever 41 and the up absorption lever 43 that constitute the mirror buffer mechanism 40 are mirror sheets. 16, the bounce of the movable mirror 15 is suppressed. Accordingly, it is possible to prevent the occurrence of image shake when observing the subject through the finder optical system 22 and the delay of the arithmetic processing using the photometry unit 23 and the distance measurement unit 24, and the finder observation in the camera 10 can be prevented. Performance and continuous shooting performance can be improved. In the mirror buffer mechanism 40, the down absorption lever 41 (buffer dowel 41 a) is held in a non-contact state (over-moving region where the mirror sheet 16 does not contact) with the mirror sheet 16 at the down position of the movable mirror 15. The up-absorbing lever 43 that absorbs the impact of the movable mirror 15 at the time of mirror up also serves as means for assuring high-precision positioning of the movable mirror 15 by the down-positioning dowel 20. That is, when the mirror is down, the down absorption lever 41 functions reliably as a buffer member, and when the movable mirror 15 reaches the down position, the down absorption lever 41 can be moved without providing a special holding member other than the up absorption lever 43. It can be held in a non-contact position with the mirror 15. Further, the urging force of the down absorption spring 42 and the up absorption spring 44 is a mechanism used not only for the buffer function of the movable mirror 15 but also for the engagement between the down absorption lever 41 and the up absorption lever 43. With the above configuration, the mirror buffer mechanism 40 has a simple structure with a small number of parts.

  FIG.15 and FIG.16 has shown embodiment using the up absorption spring 440 which consists of a torsion spring as a member which moves and energizes the up absorption lever 43 to a buffer stand-by position. The up absorption spring 440 includes a coil portion 440 a surrounding a spring support protrusion 14 h provided on the side surface of the mirror box 14, a spring arm portion 440 b engaged with a spring hook portion 14 i formed on the side surface of the mirror box 14, and the up absorption lever 43. This is a torsion spring having a spring arm portion 440c engaged with the base portion of the buffer dowel 43c, and urges the up absorption lever 43 to move downward. As in the previous embodiment, in the mirror-down state shown in FIG. 15, the up-absorbing lever 43 causes the upper end of the guide hole 43b to abut against the guide pin 14e by the urging force of the up-absorbing spring 440. Retained. When the movable mirror 15 rotates to the up position as shown in FIG. 16, the buffer contact portion 16 c of the mirror sheet 16 presses the buffer dowel 43 c and resists the urging force of the up absorption spring 440, and the up absorption lever 43. Is moved upward from the buffer standby position, and the up absorption lever 43 absorbs the impact on the movable mirror 15 and cancels the rotation restriction on the down absorption lever 41. By using the up absorption spring 440 made of a torsion spring, it is possible to reduce the operation noise when the movable mirror 15 is driven.

  In each of the above embodiments, the down absorption lever 41 is held at the non-contact position (over movement range) with the movable mirror 15 at the down position of the movable mirror 15. However, the movable mirror in FIGS. After rotating each side view so that the angle position of 15 is regarded as the up position and the angle position of the movable mirror 15 in FIGS. 12 and 16 is regarded as the down position, “Up position” will be described in the related explanation part of the mirror buffer mechanism 40. ”And“ down position ”are reversed, so that the down absorption lever 41 can be held in a non-contact position (over movement range) with the movable mirror 15 at the up position of the movable mirror 15. . In other words, the present invention can be applied to the holding of the buffer member at either the down position (finder light guide position) or the up position (retracted position) of the movable mirror, and the above embodiment can cope with both. The configuration is described.

  Furthermore, in the present invention, each buffer member is held at a non-contact position (over movement range) with the movable mirror at both the down position (finder light guide position) and the up position (retracted position) of the movable mirror. It can also be. As described above, in the previous embodiment, the up absorption lever 43 has the same over movement area as the down absorption lever 41. Specifically, the position at which the lower end of the guide hole 43a contacts the guide pin 14d is the upward movement end of the up absorption lever 43, but before the up absorption lever 43 reaches the upward movement end, the movable mirror 15 is reached. Is in contact with the upper stopper 21, the buffer dowel 43 c is separated from the buffer contact portion 16 c of the mirror sheet 16 when the up absorption lever 43 is moved to the vicinity of the upper movement end. Further, when the movable mirror 15 is turned up, an engagement portion that holds the up absorption lever 43 in the vicinity of the upper moving end (over movement range) is additionally provided on the down absorption lever 41, so that the movable mirror 15 is raised. Even in the position, the up absorption lever 43 can be held in a non-contact state with respect to the movable mirror 15. In this case, the holding means in the over-moving region of the up absorption lever 43 serves as the down absorption lever 41 and the down absorption spring 42, which are buffer members when the mirror is down, so that the down absorption lever 41 in the down position of the movable mirror 15 is used. Similar to the holding structure in the over movement area, a simple structure with a small number of parts can be achieved.

  As mentioned above, although demonstrated based on illustration embodiment, this invention is not limited to this. For example, in the mirror buffer mechanism 40 of the illustrated embodiment, the down absorption lever 41 is a rotation member having the rotation axis about the shaft 41x, and the up absorption lever 43 is a rectilinear movement member. A combination different from this may be sufficient as the movement mode (movement direction) of each buffer member which acts.

  Moreover, in this invention, the detailed shape of the buffer member with respect to a movable mirror may differ from the down absorption lever 41 and the up absorption lever 43 of illustration embodiment.

  As for the biasing members that bias each buffer member, a torsion spring such as the down absorption spring 42 and the up absorption spring 440 in the illustrated embodiment and a tension spring such as the up absorption spring 44 are used in any combination. It is also possible to use a biasing member other than a torsion spring or a tension spring.

DESCRIPTION OF SYMBOLS 10 Single-lens reflex camera 11 Camera body 12 Lens barrel 13 Lens mount 14 Mirror box 14a Through-hole 14b Spring hook part 14c Rotation restriction protrusion (1st restriction part)
14d guide pin 14e guide pin (second restricting portion)
14f Through hole 14g Spring hook 14h Spring support protrusion 14i Spring hook 15 Movable mirror (quick return mirror)
15a Main mirror 16 Mirror sheet 16a Stopper part 16b Mirror sheet boss 16c Buffer contact part 16x Mirror sheet hinge (rotating shaft of movable mirror)
17 Sub-mirror 18 Focal plane shutter 19 Image sensor (light-receiving medium for imaging)
20 Down positioning dowel 21 Upper stopper 22 Viewfinder optical system 22a Viewfinder window 23 Metering unit 24 Distance measuring unit 25 LCD monitor 30 Mirror drive mechanism 31 Motor 32 Reduction gear train 33 Cam gear 34 Mirror drive lever 34x Mirror drive lever shaft 35 Shutter charge lever 40 Mirror buffer mechanism (movable mirror shock absorption mechanism)
41 Down absorption lever (mirror advancement buffer member, buffer member)
41a Dowel for buffer (protruding contact part)
41b Rotation restriction surface (engagement mechanism, engagement surface portion)
41c Rotation allowance surface 41d Spring hook 41x Down absorption lever shaft 42 Down absorption spring (first urging member, engagement mechanism)
42a Coil part 42b 42c Spring arm part 43 Up absorption lever (mirror retraction buffer member, buffer member)
43a 43b Guide hole 43c Dowel for buffering (protruding contact part)
43d Spring hook 43e Rotation restriction arm (rotation restriction part, engagement mechanism, movement restriction part)
44 Up absorption spring (second biasing member, engagement mechanism)
45 Holding plate 440 Up absorption spring (second biasing member)
440a Coil part 440b 440c Spring arm part

Claims (9)

A finder light guide position that is located on the photographing optical path and reflects the subject light to the observation optical system, and a retreat position that is retracted from the photographing optical path and allows the subject light to pass to the imaging light receiving medium side is supported rotatably. Movable mirror;
When the movable mirror rotates from the retracted position to the finder light guide position, a mirror advancing buffer member that is pressed against the movable mirror and absorbs shock to the movable mirror; and the movable mirror is retracted from the finder light guide position. A mirror retraction buffer member that is pressed against the movable mirror when rotating to a position and absorbs shock to the movable mirror;
Have
A movable mirror impact absorbing mechanism for a camera, wherein when the movable mirror is at a finder light guide position, the mirror retracting buffer member is held at a non-contact position with respect to the movable mirror by the mirror retracting buffer member. 2. The movable mirror shock absorbing mechanism for a camera according to claim 1, wherein the first mirror advancing buffer member is rotatable about an axis substantially parallel to a rotation axis of the movable mirror, and the mirror advancing buffer member is movable. A first urging member for urging and urging the mirror in the abutting direction, and when the movable mirror is rotated from the retracted position to the finder light guide position, the movable mirror is urged by the first urging member; Press the mirror advance buffer member against the force,
The mirror retracting buffer member is movable in a straight line along a plane substantially orthogonal to the rotation axis of the mirror advance buffer member, and the mirror retracting buffer member moves and urges the mirror retracting buffer member in the contact direction with the movable mirror. An urging member, and when the movable mirror rotates from the finder light guide position to the retracted position, the movable mirror presses the mirror retracting buffer member against the urging force of the second urging member;
When the mirror retracting buffer member is at the moving end in the urging direction by the second urging member, the mirror retracting buffer is advanced onto the rotation trajectory of the mirror advancing buffer member. The rotation range of the mirror advancement buffer member is restricted by restricting the rotation range of the member, and the mirror retracting buffer member is pressed and moved in the direction opposite to the biasing direction of the second biasing member by the movable mirror. A movable mirror shock absorbing mechanism of a camera having a rotation restricting portion that retreats from above. The movable mirror shock absorbing mechanism of the camera according to claim 2, wherein the mirror advancing buffer member is:
A rotation restricting surface that comes into contact with the rotation restricting portion when the rotation restriction by the mirror retracting buffer member is received;
The mirror retraction buffer member is moved in the urging direction by the second urging member in a contact state with the rotation restriction portion of the mirror retraction buffer member located on the outer diameter side of the rotation restriction surface. A rotation permitting surface that allows the first buffer member to rotate while regulating;
A movable mirror shock absorbing mechanism of a camera having The movable mirror shock absorbing mechanism of the camera according to claim 2 or 3, wherein the mirror advance buffer member and the mirror retract buffer member are supported on a side of a mirror box that supports the movable mirror inside,
From one of a pair of opposing inner wall surfaces of the mirror box positioned across the movable mirror, a projecting contact portion provided on each of the mirror advancing buffer member and the mirror retracting buffer member that can contact the movable mirror projects. The mirror positioning portion that determines the finder light guide position of the movable mirror protrudes from the other side,
When the movable mirror contacts the mirror positioning portion and is held at the finder light guide position, the mirror advance buffer member contacts the rotation restricting portion of the mirror retract buffer member, and the protruding contact portion is A movable mirror shock absorbing mechanism of a camera held at a position separated from the movable mirror. 5. The movable mirror shock absorbing mechanism for a camera according to claim 4, wherein the first restricting portion for determining the rotation end of the mirror advance buffer member in the urging direction by the first urging member, and the second urging force. A movable mirror shock absorbing mechanism for a camera, wherein a second restricting portion for determining a moving end of a mirror retracting buffer member in a biasing direction by a member is formed in a mirror box. 6. The movable mirror impact absorbing mechanism for a camera according to claim 4 or 5, wherein the first urging member comprises a torsion spring that engages a mirror box and a mirror advancing buffer member, and the second urging member includes: A movable mirror shock absorbing mechanism for a camera comprising a tension spring that engages a mirror box and a mirror retracting buffer member. 6. The movable mirror impact absorbing mechanism for a camera according to claim 4 or 5, wherein the first urging member comprises a torsion spring that engages a mirror box and a mirror advancing buffer member, and the second urging member includes: A movable mirror shock absorbing mechanism for a camera comprising a mirror box and a torsion spring that engages with a mirror retracting buffer member. A finder light guide position that is located on the photographing optical path and reflects the subject light to the observation optical system, and a retreat position that is retracted from the photographing optical path and allows the subject light to pass to the imaging light receiving medium side is supported rotatably. Movable mirror;
A first buffer member that is pressed against the movable mirror and absorbs shock to the movable mirror when the movable mirror rotates in one direction between the retracted position and the finder light guide position;
A second buffer member that is pressed against the movable mirror when the movable mirror rotates in the other direction between the retracted position and the finder light guide position and absorbs the impact to the movable mirror; and the first buffer An engagement mechanism provided on the member and the second buffer member;
Have
At least one of the first buffer member and the second buffer member has an over-moving region that does not contact the movable mirror before the buffer moving region that is pressed and moved in contact with the movable mirror; and The engaging mechanism engages the other buffer member when one of the first buffer member and the second buffer member having the over movement area is pressed and moved by the movable mirror. Holding the buffer member in the over-movement region;
A movable mirror shock absorbing mechanism for cameras. The movable mirror shock absorbing mechanism for a camera according to claim 8, wherein at least the first buffer member has the over movement area,
The engagement mechanism is
A first urging member that urges the first buffer member in a direction opposite to the pressing movement direction by the movable mirror;
A second urging member that urges the second buffer member in a direction opposite to the pressing movement direction by the movable mirror;
An engagement surface portion provided on the first buffer member and facing the urging direction of the first urging member;
A movement restricting portion that is provided on the second buffer member and advances and retreats on the movement locus of the engagement surface portion of the first buffer member according to the movement of the second buffer member;
Have
When the second buffer member is moved in the urging direction of the second urging member, the movement restricting portion is positioned on the movement locus of the engaging surface portion of the first buffer member, and the first urging member is moved. The engagement surface portion and the movement restricting portion abut against each other by the urging force of the urging member to hold the first buffer member in the over movement region; and the second buffer member urges the second urging member. The movement restricting portion retracts from the movement locus of the engagement surface portion of the first buffer member when the movable mirror is pressed against the moving mirror;
A movable mirror shock absorbing mechanism for cameras.

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