JP2009037021A - Mirror unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust the right/left angle of a sub-mirror supported free to oscillate against the main mirror independently of the main mirror right/left angle adjustment. <P>SOLUTION: This mirror unit has a first mirror 18 which can move between the mirror-down position entering the photographing light path and the mirror-up position retreating from the photographing light path, a second mirror 19 which is pivotally supported by the shafts at the first and second oscillation support points 18c on the first mirror and can oscillate around those support points with respect to the first mirror, and an adjustment mechanism 30 to adjust the position of at least one of the above first or the second oscillation support points in the direction crossing the extending direction of the shafts. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a mirror device that is provided in a single-lens reflex camera and guides subject light to a finder device and a distance measuring device.

Conventionally, in a single-lens reflex camera, a main mirror for guiding subject light incident from a photographing lens to a finder device is provided, and a quick return mirror mechanism configured to be retractable from the photographing optical path at the time of photographing is employed. The main mirror is configured to allow part of the subject light to pass through as distance measurement (focus detection) light, reflect the light by a sub mirror, and guide the light to a distance measurement (focus detection) device. Here, an angle adjusting mechanism for the main mirror and the sub mirror is provided so that the main mirror guides subject light incident on the finder device and the sub mirror guides subject light incident on the distance measuring device to desired positions. In particular, the finder device is generally provided with a photometric device, and the deviation of the incident angle of the subject light affects the deviation of the photometric value. In the state of being arranged on the optical axis of the taking lens), in addition to the vertical angle, the horizontal angle can also be adjusted. Here, the vertical angle and the horizontal angle are the angular positions of the main mirror when the main mirror is in the mirror down state, and the vertical angle (position) is the rotation direction of the main mirror (centering on the rotation axis). The horizontal position (rotation direction when the main mirror rotates between the mirror-up position and the mirror-down position). The left-right angle (position) is the angle of the rotation axis of the main mirror with respect to the optical axis of the photographing lens. Indicates the position. In other words, the vertical angle position is an angular position in the pitching direction of the main mirror with respect to the photographing optical path, and the horizontal direction is an angular position in the yawing direction. In addition, a mechanism for reducing the bounce time of the sub-mirror has been proposed to shorten the distance measurement (focus detection) time associated with the higher speed of the mirror drive mechanism, but as a mirror angle adjustment device corresponding to such a mechanism, After adjusting the vertical angle of the main mirror and the vertical angle of the sub mirror, there has been proposed a mechanism capable of adjusting the horizontal angle of the main mirror while maintaining the angular relationship (see Patent Document 1).
JP 2005-345611 A

  By the way, in the configuration described in Patent Document 1, the sub mirror is held on the sub mirror holding frame that is swingably supported by the main mirror holding frame, but in these configurations, adjusting the left and right angles of the sub mirror is not possible. I can't. In this configuration, by ensuring the positional accuracy in the part manufacturing process of the support position of the sub mirror holding frame with respect to the main mirror holding frame, the left and right angles of the sub mirror with respect to the main mirror surface are guaranteed within a certain range of manufacturing errors. . Then, by adjusting the left and right angles of the main mirror in the camera built-in state, the left and right angles of the sub mirrors are maintained within a certain manufacturing error range.

  However, in recent years, with an increase in the number of distance measurement (focus detection) areas and miniaturization, the accuracy of the distance measurement device is required, and the distance is incident on the distance measurement device in order to reduce the displacement of the distance measurement position on the shooting screen. It is also required to reduce the deviation of the incident position of the subject light.

  An object of the present invention is to provide a mirror device capable of adjusting the left-right angle of a sub-mirror pivotally supported with respect to a main mirror separately from the adjustment of the left-right angle of the main mirror.

  In the following, the configuration of the present invention will be described with reference to one embodiment, but the present invention is not limited to the configuration of the present embodiment.

  The mirror device RM of the present invention includes a first mirror member (18) movable between a mirror-down position that enters the imaging optical path and a mirror-up position that retracts from the imaging optical path, and the first mirror member on the first mirror member. The first and second swing fulcrums (18c) provided are pivotally supported by the shaft portions (30, 32) and swing with respect to the first mirror member about the first and second swing fulcrums. Adjustment for adjusting the position of the possible second mirror member (19) and at least one of the first and second swing fulcrums in the direction intersecting the extending direction of the shaft (the yawing direction with respect to the photographing optical path L1). And a mechanism (30).

  According to the mirror device of the present invention, the adjustment of the left-right angle of the second mirror member pivotally supported with respect to the first mirror member can be performed separately from the adjustment of the left-right angle of the first mirror member. Therefore, it is possible to reduce the deviation of the incident position of the subject light incident on the distance measuring device and reduce the deviation of the distance measuring position on the photographing screen, so that the distance measuring device can perform highly accurate distance measurement. .

  Hereinafter, a digital camera (imaging device) including a mirror device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically showing a schematic configuration of a digital camera according to an embodiment of the present invention. In the following description, the XYZ orthogonal coordinate system shown in each drawing is set, and the positional relationship of each member will be described with reference to this XYZ orthogonal coordinate system.

  As shown in FIG. 1, the digital camera CM includes a camera body CB and a photographic lens CL that is interchangeably attached to the camera body CB. A finder portion FD is integrally fixed to the upper portion of the camera body CB. An image pickup device 10 such as a CCD or a CMOS is attached inside the camera body CB. The image sensor 10 captures the subject light L1 via the photographing lens CL having the optical axis L, converts it into an image signal, and outputs it. A mechanical shutter 11 for adjusting the exposure time by mechanically driving the light shielding member is provided on the front side of the image sensor 10.

  The viewfinder unit FD is an optical viewfinder for visually observing an optical image of a subject formed through a photographing lens CL, a quick return mirror (hereinafter referred to as a mirror device) RM, which will be described later, and the like. , A pentaprism 13, a photometric element 14, a photometric optical system 15, an eyepiece 16 and the like. Therefore, the photographer can view the optical image of the subject through the observation window 17 of the finder unit FD.

  In the camera body CB, in the mirror box (50 to 52) (partially not shown in FIG. 1, refer to FIG. 5) on the front side of the image sensor 10 (further than the mechanical shutter 11), a mirror device is provided. The RM is pivotably supported. A second mirror member 19 having a sub mirror 19a (see FIG. 2) is provided on the back surface side of the first mirror member 18 having the main mirror 18a (see FIG. 2) of the mirror device RM. The mirror device RM rotates in the clockwise direction from the mirror down position as shown by the broken line in FIG. 1 and the mirror down position that enters the photographing optical path of the photographing lens CL as shown by the solid line in FIG. It is configured to be movable between the mirror up position retracted from the imaging optical path. A part (near the center) of the main mirror 18a of the mirror device RM is a half mirror, and the other part is a total reflection mirror. When the mirror device RM is in the mirror down position, Most of the light is reflected by the main mirror 18a toward the finder part FD (focal plate 12), and a part of the light that has passed through the half mirror part of the main mirror 18a is reflected by the sub mirror 19a. The light reflected by the sub mirror 19a enters a phase difference detection type AF detection unit 20 provided at the bottom of the mirror box (52).

  As shown in FIG. 2, the first mirror member 18 is configured by holding the main mirror 18a by the holding frame 18b, and the second mirror member 19 is configured by holding the sub mirror 19a by the holding frame 19b. Yes. On both side surfaces of the holding frame 18 b of the first mirror member 18, only the swing fulcrum (first and second swing fulcrum) 18 c (in FIG. 2, the −X side swing fulcrum is shown. .) And a shaft hole portion (only the shaft hole portion on the -X side is shown in FIG. 2) 18d is formed at each swing fulcrum 18c. Further, through holes 19c are provided on both side surfaces of the holding frame 19b of the second mirror member 19, and bearings 19d are provided on the inner peripheral portion of the through hole 19c. Here, the bearing 19d is provided to ensure the accuracy of the shaft hole diameter. The eccentric pin (shaft portion) 30 is for adjusting the position of the sub mirror 19a in the yawing direction. The eccentric pin (shaft portion) 30 is press-fitted and fixed to the shaft hole portion 18d on the -X side through the through hole 19c on the -X side. The shaft portion 32 is press-fitted and fixed to the + X-side shaft hole portion 18d through the + X-side through hole 19c. Therefore, the second mirror member 19 is pivotally supported by the eccentric pin 30 and the pin 32 so as to be swingable with respect to the first mirror member 18. Note that toggle springs 34 and 36 are provided on the −X side and the + X side of the first mirror member 18, respectively. One end of the toggle spring 34 is hung on a spring hook 35 provided on the side of the second mirror member 19, and the other end is hung on the upper side of the first mirror member 18. One end of the toggle spring 36 is hooked on a spring hook 37 provided on the side surface of the second mirror member 19, and the other end is hooked on the side surface of the first mirror member 18. As a result, the second mirror member 19 is opened with respect to the first mirror member 18 in the mirror-down state and in the mirror-up state with respect to the first mirror member 18 with the eccentric pin 30 and the pin 32 as axes. A biasing force is applied in the closing direction, and the fitting backlash at the swinging fulcrum 18c is moved in one direction to stabilize the angle of the second mirror member 19.

  Next, referring to FIG. 3, the angle adjustment in the left-right direction of the second mirror member 19 with respect to the subject optical path (position adjustment in the YZ plane direction of the swing fulcrum 18c), that is, the camera CM is viewed from the front (+ X direction). The adjustment of the tilt angle in the left-right direction of the sub mirror 19a with respect to the subject optical path L1 (the yawing direction with respect to the optical path L1) will be described. FIG. 3A is a view as seen from a direction perpendicular to the reflecting surface of the sub mirror 19a. The second mirror member 19 is pivotally supported by an oscillating fulcrum 18c of the first mirror member 18 by an eccentric pin 30 and a pin 32. ing. Here, FIG. 3B is an AA arrow view of FIG. 3A and shows a state before the angle adjustment of the second mirror member 19 with respect to the subject optical path L1 in the left-right (yawing) direction. (C) is an AA arrow line view, and shows the state after angle adjustment of the left-right (yawing) direction of the 2nd mirror member 19 with respect to a to-be-photographed object optical path. By rotating the eccentric pin 30, as shown in FIG. 3 (c), the first swing fulcrum (left swing fulcrum shown in the drawing) extends in the direction in which the eccentric pin 30 as the shaft extends (FIG. 3 ( It is possible to decenter by d in a direction (z direction in FIG. 3) that intersects (b) x direction). As a result, the angle of the second mirror member 19 in the left-right (yawing) direction with respect to the subject optical path L1 can be adjusted.

  FIG. 4 is a view of the state in which the mirror device RM is closed (the state in the mirror up position) as viewed from the back side (the side opposite to the reflection surface). As shown in FIG. 4, the holding frame 19 b of the second mirror member 19 is pivotally supported on the swing fulcrum 18 c of the first mirror member 18 by an eccentric pin 30 and a pin 32. Here, the eccentric pin 30 has its tip 30a exposed from the swing fulcrum 18c so that it can be extracted from the swing fulcrum 18c by pushing the tip 30a in the -X direction. It is press-fitted and fixed to 18d. The pin 32 is press-fitted into the shaft hole 18d with the tip 32a exposed from the swing fulcrum 18c so that the pin 32 can be extracted from the swing fulcrum 18c by pushing the tip 32a in the + X direction. It is fixed. Therefore, after the second mirror member 19 is incorporated into the first mirror member 18, even when the second mirror member 19 needs to be replaced, the second mirror member 19 can be easily removed from the holding frame 18b of the first mirror member 18. The holding frame 19b can be removed.

  Further, the holding frame 18b of the first mirror member 18 is subjected to antireflection treatment on the surface for covering the tip portion 30a of the eccentric pin 30 and the tip portion 32a of the pin 32 exposed from the swing fulcrum 18c. The shield member 40 is affixed. Here, the shielding member 40 is made of a flocking paper or a foam-forming member such as polyurethane. The shielding member 40 includes a first convex portion 40a that covers the tip portion 30a of the eccentric pin 30, and a second convex portion 40b and a first convex portion 40a that cover the tip portion 32a of the pin 32 and the first convex portion 40a. 2 having a connecting portion 40c for connecting the convex portions 40b, reducing the generation of reflected light from the tip portion 30a of the eccentric pin 30 and the tip portion 32a of the pin 32, and holding frame for the first mirror member 18 Reduction of generation of reflected light from the back surface on the -Z side of 18b is aimed at. Accordingly, it is possible to suppress generation of unnecessary reflected light that occurs when subject light is reflected by the pins 30 and 32 in the mirror-up state, and such unnecessary reflected light is captured by the image sensor 10. It is possible to prevent the light from entering the surface.

  FIG. 5 is a perspective view illustrating a state where the mirror device RM according to the embodiment is assembled into the mirror box. As shown in FIG. 2, the mirror device is assembled by pivotally supporting the second mirror member 19 with respect to the first mirror member 18. In this state, as shown in FIG. 3C, the eccentric pin 30 is rotated, and the position in the direction intersecting the extending direction (X direction) of the shaft portions (30, 32) of the first swing fulcrum 18c. To adjust the angle of the second mirror member 19 in the left-right (yawing) direction with respect to the subject optical path L1. Thereafter, the mirror device RM is assembled in a mirror box formed by the side substrates (support members) 50 and 51 and the bottom substrate 52. An adjustment substrate 53 is attached to the outer surface (+ X side) of the side substrate 51 with screws 54. A vertical hole is used for the hole 55 through which the screw 54 passes, and the mounting position of the adjustment substrate 53 on the side substrate 51 can be adjusted in the vertical direction.

  A lever 56 is attached to the surface of the adjustment substrate 53 on the side substrate 51 side so as to be able to turn around the turning shaft 56a. The lever 56 is provided with a catch pin 57 and protrudes into the mirror box through a notch formed in the side substrate 51. A spring 58 is stretched between the upper end portion of the lever 56 and the adjustment substrate 53. The lever 56 is urged clockwise by a spring 58, and the lower end is in contact with an eccentric pin 59 provided on the adjustment substrate 53.

  The upper part of the holding frame 18 a of the first mirror member 18 is pivotally supported on the side substrate 50 by the mirror shaft 60 and is also pivotally supported on the side substrate 51 by the mirror shaft 61 via the adjustment substrate 53. Therefore, the first mirror member 18 can swing about the mirror shafts 60 and 61 as the swing shaft.

  The positioning pins 62 for positioning the first mirror member 18 and the cam pins 63 for defining the swinging motion of the second mirror member 19 are attached to the adjustment substrate 53 through holes formed in the side substrate 51, respectively. A cam portion 19e (see FIG. 2) is formed at the upper end portion of the holding frame 19b of the second mirror member 19, and a cam pin 63 is engaged with the cam portion 19e. Therefore, when the first mirror member 18 is swung, the cam surface of the cam portion 19e is guided by the cam pin 63, and the second mirror member 19 is swung with respect to the first mirror member 18.

  When adjusting the angles of the mirror members 18 and 19 with the mirror device RM assembled in the mirror box, the angle of the first mirror member 18 is adjusted, and then the angle of the second mirror member 19 is adjusted. Do. That is, first, the angle adjustment in the left-right direction of the first mirror member 18 with respect to the subject optical path L1, that is, the tilt angle in the left-right (yawing) direction of the main mirror 18a with respect to the subject optical path L1 when the camera CM is viewed from the front is performed. In this case, the vertical position of the mirror shaft 61 with respect to the mirror shaft 60 is adjusted. Here, when the vertical position of the mirror shaft 61 is adjusted, the screw 54 is loosened and the adjustment substrate 53 on which the mirror shaft 61 is fixed is moved up and down with respect to the side substrate 51. When the vertical position is determined, the adjustment board 53 is fixed to the side board 51 by tightening the screws 54.

  Next, the angle adjustment in the vertical (pitching) direction of the first mirror member 18 with respect to the subject optical path L1, that is, the adjustment of the tilt angle in the vertical (pitching) direction of the main mirror 18a with respect to the subject optical path L1 when the camera CM is viewed from the front. To do. In this case, the positioning pin 62 having an eccentric pin mechanism is adjusted to adjust the inclination of the first mirror member 18 in the vertical (pitching) direction.

  Next, the angle adjustment in the vertical direction of the second mirror member 19 with respect to the subject optical path, that is, the tilt angle in the vertical (pitching) direction of the sub mirror 19a with respect to the subject optical path L1 when the camera CM is viewed from the front is performed. In this case, the position of the catcher pin 57 is shifted by the eccentric pin 59 to adjust the inclination of the second mirror member 19 in the vertical (pitching) direction. Furthermore, the inclination of the second mirror member 19 in the left-right direction with respect to the subject optical path L1 is adjusted again. In this case, an adjustment tool 70 for rotating the eccentric pin 30 is inserted from an adjustment hole 50a which is a through hole provided at a position facing the eccentric pin 30 of the side substrate 50, and the eccentric pin is inserted. 30 is rotated to adjust the inclination of the second mirror member 19 in the left-right (yawing) direction.

  According to the mirror device of the present embodiment, the adjustment of the left-right angle of the second mirror member that is pivotally supported with respect to the first mirror member is performed separately from the adjustment of the left-right angle of the first mirror member. Since it is possible to reduce the deviation of the incident position of the subject light incident on the distance measuring device and to reduce the deviation of the distance measuring position on the shooting screen, highly accurate distance measurement is performed in the distance measuring device. be able to. In addition, the left and right angles of the second mirror member can be adjusted even after the mirror device is incorporated into the mirror box.

  In this embodiment, the holding frame 19a of the second mirror member 19 is pivotally supported on the holding frame 18a of the first mirror member 18 by the eccentric pin 30 and the pin 32. The holding frame 19 a of the two mirror member 19 may be pivotally supported on the holding frame 18 a of the first mirror member 18.

  In the present embodiment, the eccentric pin 30 is used to adjust the position in the direction intersecting the extending direction of the shaft portion of the first swing fulcrum, but the pin 32 is changed to the eccentric pin, Using the eccentric pins 30 and 32, the positions of the first and second swing fulcrums are moved in opposite directions intersecting the extending direction of the shaft portion, respectively, and the second mirror member is moved in the left and right (yawing) direction. The angle may be adjusted. In this case, the amount of eccentricity of each of the first swing fulcrum and the second swing fulcrum can be reduced.

  In the present embodiment, the eccentric pin 30 is used to adjust the position in the direction intersecting the extending direction of the shaft portion of the first swing fulcrum, but the position of the first swing fulcrum is adjusted to the axis. You may adjust the position of a 1st rocking | fluctuation fulcrum using the mechanism which can be slid in the direction which cross | intersects the direction where a part extends.

  Further, in the present embodiment, the eccentric pin 30 and the pin 32 are press-fitted and fixed to the shaft hole portions of the first swing fulcrum and the second swing fulcrum, and the second mirror member is pivotally supported with respect to the first mirror member. However, the second mirror member is pivotally supported with respect to the first mirror member by adhering and fixing the eccentric pin 30 and the pin 32 to the shaft hole portions of the first swing fulcrum and the second swing fulcrum. Also good.

  In the present embodiment, the first and second swing fulcrums of the first mirror member are formed of a resin material, but the entire first mirror member may be formed of a resin material.

  The present invention is not limited to a digital camera, and can be applied to a film camera as long as it is a single-lens reflex camera.

It is sectional drawing which shows typically schematic structure of the digital camera which concerns on embodiment. It is a perspective view which shows the assembly state of the 1st mirror member which comprises the mirror apparatus concerning Embodiment, and a 1st mirror member. It is a figure for demonstrating the angle adjustment of the left-right direction of the 2nd mirror member with respect to the 1st mirror member of the mirror apparatus concerning Embodiment. It is a perspective view which shows the state of assembly | attaching in the mirror box of the mirror apparatus concerning embodiment. It is a figure for demonstrating the shielding member affixed on the back surface of the mirror apparatus concerning embodiment.

Explanation of symbols

CM: Digital camera, CB: Camera body, CL: Shooting lens, FD: Viewfinder, RM: Mirror device, 10: Image sensor, 11: Mechanical shutter, 12 ... Focal plate, 13 ... Pental prism, 14 ... Photometric element, 15 ... Photometric optical system, 16 ... Eyepiece lens, 17 ... Observation window, 18 ... First mirror member , 18a ... main mirror, 18c ... swinging fulcrum, 19 ... second mirror member, 19a ... sub-mirror, 20 ... AF detection unit, 30 ... eccentric pin, 40 ... Shielding member, 50, 51 ... side board, 50a ... adjustment hole, 53 ... auxiliary board.

Claims (5)

A first mirror member movable between a mirror down position that enters the imaging optical path and a mirror up position that retracts from the imaging optical path;
The first and second swing fulcrums provided on the first mirror member are pivotally supported by a shaft portion and can swing with respect to the first mirror member about the first and second swing fulcrums. A second mirror member;
A mirror device comprising: an adjustment mechanism that adjusts a position of at least one of the first and second swing fulcrums in a direction intersecting a direction in which the shaft portion extends. Forming at least the first and second swing fulcrums of the first mirror member with a resin material;
2. The mirror device according to claim 1, wherein the second mirror member is pivotally supported by the shaft portion press-fitted and fixed to shaft hole portions provided at the first and second swing fulcrums. .   The mirror device according to claim 1, wherein a shielding member that shields the shaft portion is disposed on a side opposite to a reflection surface of the first mirror member.   4. The mirror device according to claim 3, wherein the surface of the shielding member is subjected to antireflection treatment. A support member for supporting the first mirror member;
The said support member has a hole for the adjustment tool which adjusts the said adjustment mechanism to penetrate in the position which opposes the said adjustment mechanism of the said 1st mirror member. The mirror apparatus as described in any one.

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