JP2011027966A - Camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a camera, hardly causing a change in angle of a sub-mirror, and reducing the bound convergence time of the sub-mirror. <P>SOLUTION: This camera (20) includes: a main mirror holding frame (2) holding a main mirror (1); a sub-mirror holding frame (4) holding the sub-mirror (3) and journaled to the main mirror holding frame; and a receiving pin (6) provided on the main mirror holding frame and abutting on the sub-mirror holding frame to stop the sub-mirror holding frame at a fixed position when the main mirror is located in a mirror down position. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  Conventionally, as a mechanism of a single-lens reflex camera, a main mirror holding frame that holds a main mirror, a sub mirror, a sub mirror holding frame that is pivotally supported by the main mirror holding frame, and a sub mirror holding frame at the mirror down position A mirror holding structure including a receiving pin is known. The angle of the sub mirror in the conventional mirror holding structure is determined by bringing a part of the sub mirror holding frame into contact with the receiving pin when the sub mirror comes to the mirror down position.

  On the other hand, in recent years, digital single-lens reflex cameras have become mainstream, and the number of shots has increased significantly compared to conventional film-type single-lens reflex cameras. For this reason, it is desired to improve durability and increase the continuous shooting frame speed.

  The sub-mirror holding frame described above moves to a predetermined position while sliding on the surface of the receiving pin after colliding with the receiving pin when the mirror is down. Therefore, every time the mirror up and mirror down are repeated, the contact surface between the receiving pin and the contact portion of the sub mirror holding frame is scraped by the frictional force. Therefore, when the number of shots increases, the angle of the sub mirror with respect to the AF module changes, and the AF performance may be degraded.

  In order to increase the continuous shooting frame speed, it is necessary to shorten the bounce convergence time of the main mirror and the sub mirror when the mirror is down. Therefore, conventionally, a mirror bounce prevention device has been proposed in which bounce is prevented by engaging a receiving pin that regulates the sub mirror at a predetermined position with the U-shaped groove of the sub mirror holding frame (for example, a patent). Reference 1). Further, there has been proposed a mirror angle adjustment device that adjusts the tilt of the sub mirror by adjusting the position of the mirror adjustment plate and the rotation position of the sub mirror adjustment pin (for example, see Patent Document 2).

Japanese Patent No. 390051 JP 2007-114512 A

  In the above-mentioned Patent Document 1, it is possible to reduce the bounce of the sub mirror, but when the mirror up and the mirror down are repeated, it is inevitable that the contact surface between the receiving pin and the abutting portion is scraped by the frictional force. For this reason, it is conceivable that the angle of the sub mirror changes as the number of shots increases. In the configuration of Patent Document 2, the angle of the sub mirror can be adjusted appropriately, but the adjustment pin of the sub mirror protrudes into the mirror box and exists near the center of the image sensor. For this reason, stray light from the photographic lens is reflected on the surface of the adjustment pin and enters the image sensor, which may cause a ghost in the captured image.

  An object of the present invention is to provide a camera in which the angle change of the sub mirror is small and the bounce convergence time of the sub mirror can be shortened.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
According to the first aspect of the present invention, a main mirror holding frame (2) for holding the main mirror (1) and a sub mirror holding frame (4) which holds the sub mirror (3) and is pivotally supported by the main mirror holding frame. ) And receiving pins (6, 6a) that are provided on the main mirror holding frame and abut against the sub mirror holding frame to lock the sub mirror holding frame in place when the main mirror is in the mirror down position. And a camera (20).
The invention according to claim 2 is the camera (20) according to claim 1, wherein the receiving pin (6a) is eccentrically attached to the main mirror holding frame (2) so as to be rotatable. It is a pin.
A third aspect of the present invention is the camera (20) according to the second aspect, wherein the eccentric pin (6a) is connected to the external mirror when the main mirror (1) is in the mirror up position. It is attached to a position where a rotation operation is possible.
Note that the configuration described with reference numerals may be modified as appropriate, and at least a part of the configuration may be replaced with another component.

  ADVANTAGE OF THE INVENTION According to this invention, the camera which can reduce the angle change of a submirror and can shorten the bound convergence time of a submirror can be provided.

It is sectional drawing of the camera concerning 1st Embodiment. It is a side view of a mirror holding mechanism part when a main mirror exists in a mirror down position in a 1st embodiment. It is a side view of a mirror holding mechanism part when a main mirror exists in a mirror down position in a 1st embodiment. It is sectional drawing of a mirror holding | maintenance mechanism part when a main mirror exists in a mirror up position in 2nd Embodiment. It is a perspective view of the receiving pin in 2nd Embodiment.

  Hereinafter, embodiments of a camera according to the present invention will be described with reference to the drawings. In the drawings shown below, an XYZ orthogonal coordinate system is provided as necessary to facilitate explanation and understanding. In this coordinate system, the direction toward the left as viewed from the photographer at the camera position (hereinafter referred to as the normal position) when the photographer shoots a horizontally long image with the optical axis A horizontal is defined as the X plus direction. Further, the direction toward the upper side in the normal position is defined as the Y plus direction. Further, the direction toward the subject at the normal position is taken as the Z direction.

First, the first embodiment will be described. FIG. 1 is a cross-sectional view of a camera 20 according to the first embodiment. FIG. 2 is a side view of the mirror holding mechanism 30 when the main mirror 1 is in the mirror down position in the first embodiment. FIG. 3 is a side view of the mirror holding mechanism 30 when the main mirror 1 is in the mirror down position in the first embodiment.
1 is a cross-sectional view when the camera 20 is divided vertically along the optical axis A. FIG. In FIG. 1, the configuration of the mirror holding mechanism unit 30 is illustrated in a simplified manner. For this reason, a part shape differs from the mirror holding | maintenance mechanism part 30 shown in FIG.2 and FIG.3.

  The camera 20 is configured as a digital single lens reflex camera. As shown in FIG. 1, the camera 20 includes a camera body 21, an image display unit 22, a mount unit 25, a mirror holding mechanism unit 30, a finder unit 40, an AF module 50, a shutter unit 60, and an imaging unit 70.

  The camera body 21 is a main frame that fixes each part of the camera 20. The image display unit 22 is a liquid crystal display that is provided at the rear of the camera 20 and displays a subject image captured by the imaging unit 70, information related to an operation, a captured subject image, and the like. The mount part 25 is a part to which a photographing lens (not shown) is detachably attached. The photographing lens includes a lens group that emits incident subject light to the mirror holding mechanism unit 30.

  The finder unit 40 includes a finder screen 41, a penta roof prism 42, and an eyepiece unit 43. The finder screen 41 is a screen on which subject light reflected when the mirror holding mechanism 30 is in the observation position (mirror down position) is incident and imaged. The penta roof prism 42 is a polygonal prism that emits subject light imaged by the finder screen 41 to the eyepiece 43. The eyepiece 43 is an eyepiece optical system disposed at a position where the subject light emitted from the penta roof prism 42 is incident.

  The AF module 50 is a sensor that receives the subject light reflected by the mirror holding mechanism unit 30 and detects distance measurement information for focus adjustment. The shutter unit 60 is disposed behind the mirror holding mechanism unit 30. The shutter 60 receives subject light when the mirror holding mechanism 30 is in the photographing position (mirror up position). The shutter unit 60 includes a plurality of shutter blade groups (not shown), opens and closes the shutter blade groups according to a shooting instruction by a release switch (not shown), and makes subject light incident on the imaging unit 70.

  The imaging unit 70 is provided at a position where subject light that has passed through the shutter unit 60 enters. The imaging unit 70 includes a low-pass filter 71 and an imaging element 72. The image sensor 72 exposes the subject light incident via the low-pass filter 71, converts it into an electrical image signal, and outputs it to an image processing unit (not shown).

  The mirror holding mechanism unit 30 includes a main mirror holding frame 2 and a sub mirror holding frame 4. The mirror holding mechanism 30 is provided at a position where subject light emitted from a photographing lens (not shown) is incident. The mirror holding mechanism unit 30 is a mechanism that selectively causes subject light to enter the finder unit 40, the AF module 50, the shutter unit 60, and the imaging unit 70.

  The main mirror holding frame 2 includes a main mirror 1. The main mirror 1 is a reflection mirror that reflects subject light to the finder unit 40. The reflecting surface of the main mirror 1 is provided with a semi-transmissive mirror (not shown) that transmits a part of the subject light. Part of the subject light transmitted through the semi-transmissive mirror is incident on the sub-mirror 3 provided at the rear part thereof.

  As shown in FIG. 2, the main mirror holding frame 2 is rotatably supported by a main support shaft 8. The main support shaft 8 is provided with a return spring (not shown) made of a coil spring or the like. The main mirror holding frame 2 is urged counterclockwise about the main support shaft 8 by the return spring.

  In the mirror down position shown in FIG. 2, it is necessary to stop the main mirror 1 at a predetermined angle. For this reason, a stopper pin 7 for stopping the main mirror holding frame 2 at a predetermined angle is provided. The stopper pin 7 is provided on the camera body 21. As shown in FIG. 2, when the main mirror holding frame 2 comes into contact with the stopper pin 7, the main mirror holding frame 2 stops at a predetermined angle in the mirror down position.

  On the other hand, the sub mirror holding frame 4 includes a sub mirror 3. The sub mirror 3 is a reflection mirror that reflects subject light transmitted through the semi-transmission mirror of the main mirror 1 and guides it to the AF module 50. The sub mirror holding frame 4 is rotatably attached to the main mirror holding frame 2 by a sub spindle 9.

  The sub spindle 9 is provided with a return spring (not shown) such as a toggle spring. The sub mirror holding frame 4 is urged clockwise or counterclockwise about the sub spindle 9 by the return spring. That is, the sub mirror holding frame 4 is biased clockwise when the mirror is raised when the angle with respect to the main mirror holding frame 2 becomes less than a predetermined angle. As a result, as shown in FIG. 3, the sub mirror holding frame 4 jumps up to the retracted position together with the main mirror holding frame 2.

  Further, the sub mirror holding frame 4 is urged counterclockwise when the angle with respect to the main mirror holding frame 2 exceeds a predetermined angle when the mirror is down. As a result, the sub-mirror holding frame 4 moves in the direction of a receiving pin 6 described later, as shown in FIG.

  In the mirror down position shown in FIG. 2, it is necessary to stop the sub mirror 3 at a predetermined angle. For this reason, a receiving pin 6 for stopping the sub mirror holding frame 4 at a predetermined angle is provided. The receiving pin 6 is provided on the main mirror holding frame 2. The main mirror holding frame 2 includes a bracket 10 in the vicinity of the main support shaft 8. The receiving pin 6 is attached to the bracket 10. As shown in FIG. 2, the receiving pin 6 is attached close to the sub-support shaft 9 that is the rotation center of the sub-mirror holding frame 4.

  The receiving pin 6 is a cylindrical member. A part of the sub-mirror holding frame 4 comes into contact with the cylindrical outer peripheral surface. The sub-mirror holding frame 4 has a triangular convex portion 11 on the receiving pin 6 side. One side of the convex portion 11 serves as a contact portion 4 a that contacts the outer peripheral surface of the receiving pin 6. When the contact portion 4a contacts the outer peripheral surface of the receiving pin 6, the sub mirror holding frame 4 stops at a predetermined angle in the mirror down position.

  In the present embodiment, the receiving pin 6 is provided on the main mirror holding frame 2. For this reason, when the main mirror holding frame 2 moves to the mirror up position, the receiving pin 6 also moves together with the main mirror holding frame 2. As a result, the receiving pin 6 retreats from the optical path of the subject light together with the main mirror holding frame 2.

  Next, the operation of the mirror holding mechanism 30 in this embodiment will be described. When moving from the mirror-up position shown in FIG. 3 to the mirror-down position shown in FIG. 2, the main mirror holding frame 2 and the sub mirror holding frame 4 rotate counterclockwise. At this time, the sub mirror holding frame 4 rotates with respect to the main mirror holding frame 2 around the sub support shaft 9. The receiving pin 6 is provided on the main mirror holding frame 2. Therefore, the reaction force received when the contact portion 4a of the sub mirror holding frame 4 collides with the receiving pin 6 when the mirror is down is only the kinetic energy of the sub mirror 3 and the sub mirror holding frame 4.

  On the other hand, the main mirror holding frame 2 rotates counterclockwise around the main spindle 8 as in the prior art. Then, after the sub mirror holding frame 4 stops rotating, it comes into contact with the stopper pin 7 and stops. While the main mirror holding frame 2 rotates, the contact portion 4 a of the sub mirror holding frame 4 remains in contact with the receiving pin 6. For this reason, the relative sliding of the contact part 4a and the receiving pin 6 hardly arises.

According to 1st Embodiment mentioned above, there exist the following effects.
(1) In the conventional camera in which the receiving pin of the sub mirror is provided on the camera body as in the conventional case, the receiving pin of the sub mirror and the sub mirror holding frame are moved before the receiving pin of the main mirror contacts the main mirror holding frame when the mirror is down. In order to make contact, the structure is such that a certain distance slides between the sub-mirror holding frame and the sub-mirror receiving pin. On the other hand, in the camera of this embodiment, when the sub mirror holding frame 4 rotates to the mirror down position, only the kinetic energy when the sub mirror holding frame 4 rotates is applied to the receiving pin 6. Further, while the main mirror holding frame 2 rotates, the relative sliding between the contact portion 4a of the sub mirror holding frame 4 and the receiving pin 6 hardly occurs. For this reason, the frictional force between the contact part 4a of the sub-mirror holding frame 4 and the receiving pin 6 is reduced, and the contact surface is less worn. Therefore, even when used for a long period of time, the angle change of the sub mirror 3 can be reduced, and the influence on the AF performance can be reduced.
(2) In the conventional camera in which the receiving pin of the sub mirror is provided on the camera body as in the conventional case, when the sub mirror holding frame rotates to the mirror down position and the sub mirror holding frame collides with the receiving pin of the sub mirror, Kinetic energy when the main mirror 1, the main mirror holding frame 2, the sub mirror 3, and the sub mirror holding frame 4 are rotated acts on the receiving pin. On the other hand, in the camera of this embodiment, when the sub mirror holding frame 4 rotates to the mirror down position and the sub mirror holding frame 4 collides with the receiving pin 6, the sub mirror 3 and the sub mirror holding frame 4 rotate on the receiving pin 6. Only kinetic energy when moving acts. For this reason, the bounce convergence time of the sub mirror holding frame 4 when the mirror is down can be shortened. Therefore, the continuous shooting frame speed can be increased.
(3) When the sub mirror holding frame 4 rotates to the mirror up position, the receiving pin 6 moves together with the main mirror holding frame 2 and retreats from the optical path of the subject light together with the main mirror holding frame 2. For this reason, stray light from the photographing lens is not reflected on the surface of the receiving pin 6 and enters the image sensor 72. Therefore, it is possible to suppress the occurrence of ghost during shooting.

  Next, a second embodiment will be described. FIG. 4 is a cross-sectional view of the mirror holding mechanism 30A when the main mirror is in the mirror up position in the second embodiment. FIG. 4 shows a cross section when the mirror holding mechanism 30A is vertically divided along the optical axis A when viewed from the X plus direction (see FIG. 1). FIG. 5 is a perspective view of the receiving pin 6a. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals.

In the present embodiment, the receiving pin 6a and the stopper pin 7a are eccentric pins. As shown in FIG. 5, the receiving pin 6 a includes a cylindrical abutting tube portion 13. The contact portion 4 a of the sub mirror holding frame 4 contacts the outer peripheral surface of the contact cylinder portion 13. A shaft portion 14 is provided on one surface of the contact cylinder portion 13. A hexagonal hole 13a into which a hexagon wrench is inserted is provided on the other surface of the abutting tube portion 13.
The shaft portion 14 is a portion attached to the bracket 10 of the main mirror holding frame 2. In the present embodiment, the receiving pin 6 a is caulked and fixed to the bracket 10. The shaft portion 14 is provided at a position eccentric from the axis of the abutting cylinder portion 13. That is, the receiving pin 6a is configured as an eccentric pin. As will be described later, the receiving pin 6a is fixed by caulking with a strength that enables rotation by a tool.

  The receiving pin 6 a is fixed by caulking so that the hole 13 a faces the inside of the mirror box of the camera body 21. Thereby, when the main mirror holding frame 2 is in the mirror up position, the receiving pin 6a can be rotated. Even in the mirror down position, the rotation operation can be performed later when the shutter unit 60 is not disposed, such as during the assembly process.

  According to the configuration of the present embodiment, with the receiving pin 6a attached to the main mirror holding frame 2, the receiving pin 6a can be rotated by inserting a hexagon wrench into the hole 13a. Thereby, the position where the contact part 4a of the sub mirror holding frame 4 and the contact cylinder part 13 contact can be adjusted. Therefore, by adjusting the mirror angle of the sub mirror 3 to an appropriate angle, variations in parts and assembly can be corrected. Moreover, it arrange | positions so that the hole 13a of the receiving pin 6a may face the inner side of a mirror box. For this reason, even when the camera 20 is in a completed state, the eccentric position can be adjusted by setting the mirror up position.

The stopper pin 7a is configured similarly to the receiving pin 6a. That is, similarly to the receiving pin 6a, the stopper pin 7a can be rotated by inserting a hexagon wrench into the hole 13a (in FIG. 4, the same reference numerals as the receiving pin 6a are given). Therefore, by adjusting the mirror angle of the main mirror 1 to an appropriate angle, it is possible to correct variations in parts and assembly.
(Deformation)

The present invention is not limited to the above-described embodiment, and various modifications and changes as described below are possible, and these are also within the scope of the present invention.
(1) The cross section of the receiving pin 6 (6a) is not limited to a circle, but may be another shape such as a semicircle or an ellipse. Further, the shape of the convex portion 11 of the sub mirror holding frame 4 is not limited to a triangle, and may be another shape.
(2) The hole 13a of the receiving pin 6a is not limited to the shape corresponding to the hexagon wrench, and may be a plus / minus driver groove or a shape into which only a dedicated tool can be inserted. Moreover, it is good also as a structure which can replace | exchange the multiple types of receiving pin 6 from which an outer diameter differs. In this case, the mirror angle of the sub mirror 3 can be adjusted to an appropriate angle by attaching the receiving pin 6 having an appropriate outer diameter.
(3) In this embodiment, an example in which the present invention is applied to a digital single-lens reflex camera has been described. However, the present invention is not limited to this, and can be applied to, for example, a film type single-lens reflex camera.

  In addition, although embodiment and a deformation | transformation form can also be used in combination as appropriate, detailed description is abbreviate | omitted. Further, the present invention is not limited to the embodiment described above.

  1: main mirror, 2: main mirror holding frame, 3: sub mirror, 4: sub mirror holding frame, 6, 6a: receiving pin, 7, 7a: stopper pin, 8: main spindle, 9: sub spindle, 20: camera

Claims (3)

A main mirror holding frame for holding the main mirror;
A sub mirror holding frame that is supported by the main mirror holding frame and holding the sub mirror;
A receiving pin that is provided on the main mirror holding frame and stops the sub mirror holding frame at a fixed position by contacting the sub mirror holding frame when the main mirror is in a mirror down position;
A camera comprising: The camera according to claim 1,
The camera according to claim 1, wherein the receiving pin is an eccentric pin that is rotatably attached to the main mirror holding frame. The camera according to claim 2,
2. The camera according to claim 1, wherein the eccentric pin is attached to a position where an external turning operation is possible when the main mirror is in a mirror up position.

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