HK1176689B - Camera - Google Patents

Abstract

A mirror contact member includes a first eccentric portion that is eccentric with respect to a rotation center of the mirror contact member, and a second eccentric portion that is eccentric with respect to the rotation center of the mirror contact member substantially at the same eccentricity as that of the first eccentric portion. When a mirror is displaced to a mirror-down state, the mirror is contacted with the first eccentric portion. A bounce regulation member is disposed to be rotatable about the second eccentric portion.

Description

Camera with a camera module

Technical Field

The present invention relates to a camera (camera) such as a single-lens reflex camera, and more particularly, to a camera including a mechanism that suppresses bouncing (rebounding) of a rotatable mirror.

Background

The single-lens reflex camera includes a main mirror for reflecting light from a subject and guiding the reflected light to an optical system of a viewfinder, and a sub-mirror for guiding the light having passed through the main mirror to a focus detector. The main mirror and the sub-mirror are each displaceable to a mirror-down state in which both mirrors are located in the photographing optical path and a mirror-up state in which both mirrors are retracted from the photographing optical path.

When the main mirror and the sub-mirror are displaced to the mirror-down state, the main mirror and the sub-mirror collide against a stopper disposed at the mirror box, thereby causing the main mirror and the sub-mirror to bounce (rebound off the stopper). The viewfinder image can be stabilized by suppressing the bounce of the main mirror. In addition, the focus detection operation can be started early by suppressing the bounce of the sub-mirror.

The following technique is disclosed in Japanese patent laid-open No. 9-203972.

The main mirror 1 and the main mirror holding frame 2 are displaced to the mirror-down state and collide with the main mirror receiving member 29 in the observation position. When the main mirror 1 and the main mirror holding frame 2 collide with the main mirror receiving member 29, the inertia brake plate 21 and the main mirror receiving member 29 rotate. In conjunction with the rotation of the inertia brake plate 21 and the main mirror receiving member 29, the sub-mirror holding member 31 rotates to come into a bounce trajectory of the sub-mirror 11. As a result, the sub-mirror holding portion 32 of the sub-mirror holding member 31 contacts the sub-mirror 11, thereby reducing the bounce of the sub-mirror 11.

Disclosure of Invention

With the technique disclosed in japanese patent laid-open No. 9-203972, when the main mirror 1 and the main mirror holding frame 2 collide with the main mirror receiving member 29, the momentum of the main mirror 1 and the main mirror holding frame 2 is transmitted to the inertia brake plate 21 and the main mirror receiving member 29.

However, in japanese patent laid-open No. 9-203972, the sub-mirror does not include a bounce suppression mechanism like the bounce suppression mechanism provided for the main mirror, and only the bounce range of the sub-mirror is limited. In addition, when the mirror down position of the mirror is adjusted, the mirror bounce range is changed.

An embodiment of the present invention provides a camera including: a mirror (mirror); a mirror contact member with which the mirror is contactable; and a bounce limiting member including a bounce limiting portion with which the mirror is contactable when the mirror bounces from the mirror contact member, wherein the mirror contact member is provided to be rotatable about a rotation center, the mirror contact member includes a first eccentric portion that is eccentric with respect to the rotation center of the mirror contact member, and a second eccentric portion that is eccentric with respect to the rotation center of the mirror contact member by an eccentric amount that is the same as that of the first eccentric portion, the mirror being in contact with the first eccentric portion when the mirror is displaced to a mirror-down state, the bounce limiting member being arranged to be rotatable about the second eccentric portion.

According to the embodiment of the present invention, a camera including the following mirror driving mechanism can be obtained: in the mirror driving mechanism, when the mirror down position of the mirror is adjusted, the mirror bounce range is not changed.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

Drawings

Fig. 1 is a schematic view showing an overall configuration of a camera according to an embodiment of the present invention.

Fig. 2A to 2C are explanatory diagrams for explaining the operation of the mirror driving mechanism.

Fig. 3 is a diagram for explaining a mirror driving sequence.

Fig. 4 is an explanatory diagram showing the configuration of the main mirror balancer and the configuration of the sub mirror balancer.

Fig. 5A and 5B are explanatory diagrams for explaining the operation of the main mirror balancer and the operation of the sub-mirror balancer.

Fig. 6 is an exploded perspective view showing the sub-mirror balancer mechanism located on the left side of the sub-mirror frame.

Fig. 7 is an explanatory diagram for explaining the operation of the sub-mirror balancer mechanism located on the left side of the sub-mirror frame.

Fig. 8A and 8B are explanatory diagrams for explaining the operation of the sub-mirror balancer mechanism located on the left side of the sub-mirror frame.

Fig. 9 is a front view of the shutter device.

Fig. 10A to 10C are explanatory views showing a detailed structure of the mirror box.

Detailed Description

A camera according to an embodiment of the present invention will be described below with reference to the accompanying drawings. The camera according to the present embodiment is implemented as a single-lens reflex still camera using a silver halide film or as a single-lens reflex digital camera using a CCD sensor or a MOS type solid-state image pickup element (image pick-up element).

Fig. 1 is a schematic diagram showing an internal overall configuration of a single-lens reflex digital camera according to the present embodiment.

In fig. 1, a photographing lens 10 is detachably attached to a main body of a digital camera. The subject image is focused on an image plane (image plane) by the photographing lens 10. Although not shown, the photographing lens 10 is constituted by a lens driver, a diaphragm blade unit for exposure control, a diaphragm driver for driving the diaphragm blade unit, and the like.

The main mirror 100 is configured as a half mirror (half mirror). When the main mirror 100 is in the mirror-down state, the main mirror 100 reflects the object image focused by the photographing lens 10 toward the focusing screen. At this time, the main mirror 100 allows a part of the subject image to pass through the main mirror 100 toward the sub mirror 200. The sub mirror 200 reflects a portion of the object image (light) that has been transmitted through the main mirror 100 toward the focus detector 11.

The main mirror 100 is driven by a mirror driving mechanism (described later), so that the main mirror 100 is displaced to a mirror-down state in which the main mirror 100 is located in the optical path of the object light beam to guide the object image to the focusing screen or a mirror-up state in which the main mirror 100 is retracted from the optical path of the object light beam to guide the object image to the image pickup element 13.

When the main mirror 100 is driven by a mirror driving mechanism (described later), the sub mirror 200 is displaced in conjunction with the main mirror 100. More specifically, when the main mirror 100 is in the mirror-down state, the sub-mirror 200 guides (directs) the light beam that has passed through the main mirror 100 to the focus detector 11. On the other hand, when the main mirror 100 is in the mirror-up state, the sub-mirror 200 is retracted from the optical path of the object beam together with the main mirror 100.

The pentaprism 14 reflects the subject image focused on the focusing screen after converting the subject image into an erect normal image.

The eyepiece lens 15 guides the subject image, which has been converted into an erect normal image by the pentaprism 14 and reflected, to the photographer's eyes.

The photometry device 16 measures the luminance of the object image that has been focused on the focusing screen via the pentaprism 14. Exposure control during exposure is performed based on an output signal of the photometry device 16.

The focus detector 11 detects the defocus amount of the object image. The focus adjustment is performed by controlling a lens driver for the photographing lens 10 based on an output signal of the focus detector 11.

The shutter device 12 mechanically controls incidence of the object beam to the image forming surface.

The image pickup element 13 picks up an object image focused by the photographing lens 10 and converts the object image into an electric signal. For example, a CCD or MOS type two-dimensional image pickup device is used as the image pickup element 13.

The photographing operation in the digital camera according to the present embodiment will be described below.

Before starting photographing, the subject image incident via the photographing lens 10 is brought into a state in which the photographer can confirm the subject image oriented by the main mirror 100 and the pentaprism 14 via the eyepiece lens 15. At this time, a part of the object image enters the focus detector 11 via the sub-mirror 200. When the photographer operates the switch, the photographing lens 10 is driven according to the object distance information detected by the focus detector 11. In the above manner, focusing can be performed. In addition, the photometry device 16 measures the subject luminance, thereby determining a lens aperture value and a shutter exposure time.

When photographing is performed with a release operation by a photographer, the main mirror 100 and the sub-mirror 200 are retracted upward from the photographing optical path and the blades of the shutter device 12 are opened, thereby making an object image incident on the image pickup element 13. After the appropriate exposure time has elapsed, the blades of the shutter device 12 are operated to close the opening of the image frame (image frame), and the main mirror 100 and the sub-mirror 200 are returned into the optical path for photography. Thereby completing the photographing operation.

The operation of the mirror driving mechanism will be described below with reference to fig. 2A to 2C.

Fig. 2A shows a standby state before release, i.e., a state after mirror-down and loading operations are completed.

The substrate 300 to which the mirror driving mechanism is mounted includes a hole in which the rotation shaft 101 of the main mirror 100 is fitted and an arc-shaped hole along which the driving shaft 102 of the main mirror 100 rotates. A mirror-down spring 100Sp for urging the main mirror 100 in the downward direction is held against the drive shaft 102 of the main shaft 100.

The mirror lever 310 rotates about the rotation center 310 d. The down hook lever 340 is mounted to the mirror lever 310. The lower hook lever 340 rotates about the rotation center 340 a. The attraction lever 370 and the separation lever 360 are integral with each other and both rotate about the rotation center 360a of the separation lever 360. An attraction portion 380a that can be attracted by the electromagnet 380 is fixed to the tip of the attraction lever 370.

The electromagnet 380 includes a magnet, a coil, and a yoke. In the non-energized state, the attraction portion 380a is held in close contact with the yoke by magnetic force. When the coil is energized, the magnetic force is removed, and the attraction portion 380a is separated from the yoke.

The separation spring 360Sp biases the suction portion 380a in a direction to separate the suction portion 380a from the yoke. In other words, the detaching spring 360Sp urges the attraction lever 370 in a direction to rotate the attraction lever 370 rightward as viewed in fig. 2A about the rotation center 360a of the detaching lever 360. When the attraction portion 380a is attracted to the yoke, the attraction portion 380a is held by the yoke with a force larger than the urging force of the separation spring 360 Sp.

As shown in fig. 2A, in the standby state before release, the upper hook lever 350 and the engagement portion 310a of the mirror lever 310 are engaged with each other. With this engagement, the mirror lever 310 is held in the state shown in fig. 2A against the urging force of the mirror-up spring 310 Sp. In addition, in the state shown in fig. 2A, the down hook lever 340 and the engagement portion 320a of the mirror drive lever 320 are engaged with each other.

The mirror-up operation will be described below.

When a pulse is supplied to the electromagnet 380 according to the release signal, the attraction lever 370 to which the attraction portion 380a is fixed and the separation lever 360 integrated with the attraction lever 370 are rotated leftward (counterclockwise) about the rotation center 360a of the separation lever 360 by the spring force of the separation spring 360 Sp.

When the separation lever 360 rotates leftward, the roller 360b of the separation lever 360 contacts the contact portion 350b of the upper hook lever 350, and thus the upper hook lever 350 rotates leftward about the rotation center 350 a. In the case where the upper hook lever 350 is rotated leftward, the engagement between the upper hook lever 350 and the engagement portion 310a of the mirror lever 310 is released.

When the engagement between the upper hook lever 350 and the engagement portion 310a of the mirror lever 310 is released, the mirror lever 310 rotates leftward about the rotation center 310d by the spring force of the mirror-up spring 310 Sp. At this time, since the engaging portion 320a of the mirror drive lever 320 engages with the down hook lever 340, the mirror drive lever 320 rotates leftward about the rotation center 310d of the mirror lever 310. When the mirror drive lever 320 is rotated leftward, the cam portion 320b of the mirror drive lever 320 pushes up the drive shaft 102 of the main mirror, thereby performing the mirror-up operation.

The spring force of the mirror-up spring 310Sp is sufficiently larger than that of the mirror-down spring 100 Sp. Therefore, the mirror-up operation can be performed at high speed.

Fig. 2B shows a state after the mirror-up operation is completed.

The operation sensor 330 is fixed to the mirror driving lever 320, and completion of the mirror-up operation is detected by a up switch (UPSW)303 including a photo interrupter.

The mirror lever 310 includes a suction cam portion 310 b. When the mirror lever 310 is rotated leftward, the attraction cam portion 310b comes into contact with the roller 360c of the separation lever 360, thereby rotating the separation lever 360 rightward (clockwise) against the spring force of the separation spring 360 Sp. In the case where the separation lever 360 is rotated rightward, the attraction portion 380a in a state of being separated from the electromagnet 380 is attracted to the electromagnet 380 again.

In addition, since the engaging portion 320a of the mirror drive lever 320 engages with the down hook lever 340, the down hook lever 340 rotates leftward about the rotation center 310d of the mirror lever 310 together with the mirror lever 310 and the mirror drive lever 320. The releasing portion 340b of the lower hook lever 340 moves to a position where it can contact the roller 360b of the separation lever 360. After the end of the bounce generated along with the mirror-up operation, the exposure operation is performed, and the process proceeds to the mirror-down step after the exposure operation.

The mirror-down operation will be described below.

When a pulse is supplied to the electromagnet 380 in the mirror-up state of fig. 2B, the attraction lever 370 and the separation lever 360, both of which are associated with the attraction portion 380a, are rotated leftward (counterclockwise) by the spring force of the separation spring 360 Sp.

When the separation lever 360 is rotated leftward, the roller 360b of the separation lever 360 contacts the release portion 340b of the down hook lever 340, so that the down hook lever 340 is rotated rightward (clockwise) about the rotation center 340 a. When the down hook lever 340 is rotated rightward, the engagement between the down hook lever 340 and the engagement portion 320a of the mirror drive lever 320 is released. When the engagement between the down hook lever 340 and the engagement portion 320a of the mirror drive lever 320 is released, the spring force of the mirror-down spring 100Sp is caused to act on the drive shaft 102 of the main mirror. As a result, the mirror drive lever 320 rotates rightward about the rotation center 310d of the mirror lever 310.

Fig. 2C shows a state after the mirror-down operation is completed.

The main mirror balancer 400 is disposed at the base plate 300 of the mirror box. When the main mirror 100 is in contact with the main mirror balancer 400, the main mirror balancer 400 rotates rightward against the spring force of the main mirror balancer springs 400Sp, thereby relaxing the impact generated along with the mirror-down operation of the main mirror 100. Further, the main mirror balancer 400 collides with the buffer portion 302 located at the front end of the main mirror balancer 400 when rotating rightward, thereby further mitigating the impact applied to the main mirror balancer 400.

The sub-mirror balancer 500 is disposed at the base plate 300 of the mirror box. When the sub-mirror 200 is in contact with the sub-mirror balancer 500, the sub-mirror balancer 500 rotates rightward against the spring force of the sub-mirror balancer springs 500Sp (see fig. 5A and 6), thereby relaxing the impact generated with the mirror-down operation of the sub-mirror 200.

The mirror loading operation will be described below.

In the state of fig. 2C, the roller 310C disposed at the charging portion of the mirror lever 310 is pressed leftward by the charging lever (not shown), whereby the mirror lever 310 is rotated rightward about the rotation center 310d of the mirror lever 310 against the spring force of the mirror-up spring 310 Sp. In the case where the mirror lever 310 is rotated rightward, the attraction cam portion 310b of the mirror lever 310 contacts the roller 360c of the detaching lever 360, whereby the detaching lever 360 is rotated rightward against the spring force of the detaching spring 360 Sp.

In the case where the separation lever 360 is rotated rightward, the attraction lever 370 is also rotated rightward, so that the attraction portion 380a in the separated state is attracted to the electromagnet 380 again.

When the mirror lever 310 is rotated rightward in the state of fig. 2C, the lower hook lever 340 is engaged with the engagement portion 320a of the mirror driving lever 320, and the upper hook lever 350 is engaged with the engagement portion 310a of the mirror lever 310. As a result, the mirror loading operation is completed and the mirror driving mechanism returns to the state of fig. 2A.

Although in the present embodiment, as described above, the electromagnet is used as the trigger for starting the mirror-up operation and the mirror-down operation and the spring is used as the drive source for the mirror-up operation and the mirror-down operation, the mirror drive mechanism is not limited to the above configuration. For example, an electromagnetic motor, a stepping motor, or an ultrasonic motor may also be used as the drive source in the mirror drive mechanism.

However, when an electromagnetic motor is used to perform a mirror operation, the operation start time tends to vary due to, for example, inertia and temperature characteristics of the motor. In addition, a speed reduction mechanism is required and a mechanical delay time is generated in transmitting the driving force. Therefore, as in the above-described embodiments, in the mirror driving mechanism which requires high speed and high accuracy, it is appropriate to employ an electromagnet as a trigger and perform mirror operation using a spring force.

Fig. 3 is a diagram illustrating a mirror driving sequence (sequence) of the camera according to the present embodiment. In the mirror driving sequence of the camera according to the present embodiment, as shown in fig. 3, the loading operation is started before the mirror-down operation is completed. Therefore, even during arithmetic operations for AF (auto focus) and AE (auto exposure), the loading operation can be continued regardless of the accuracy with which the mirror is stopped. In addition, the variation in the loading operation does not affect the mirror operation speed and the arithmetic operation time for AF and AE. The influence of such a change on the continuous shooting is also small.

The configuration of the main mirror balancers 400 and 410 and the configuration of the sub mirror balancers 500 and 510 will be described below with reference to fig. 4, 5A, and 5B.

The main mirror frame 100a for holding the main mirror 100 has hinge (hinge) shaft portions (spindles) 101, which hinge shaft portions 101 are formed on the left and right sides of the main mirror frame 100a, respectively, and serve as rotation centers. A driving shaft 102 for rotating the main mirror 100 is formed at one side of the main mirror frame 100 a. Contact plates 103 and 104 formed of a different member from the main mirror frame 100a are disposed at the left and right ends of the main mirror 100, respectively.

The main mirror frame 100a is made of a lightweight material such as aluminum or resin in many cases to reduce the moment of inertia. If the contact plates 103 and 104 are made of the same material as that of the main mirror frame 100a, the durability of the contact plates 103 and 104 may be deteriorated. Therefore, the contact plates 103 and 104 are made of a material having a higher strength than that of the material of the main mirror frame 100a, such as stainless steel, or formed of a rubber member having an impact absorbing property.

As shown in fig. 4 and 5A, the main mirror balancer 400 is disposed on the left side (one side) of the main mirror frame 100 a. The main mirror balancer 400 includes a shaft portion 401 serving as a rotation center, a contact shaft 402, a main mirror angle adjusting portion 403, and a balancer weight 404, the balancer weight 404 being made of a material having a large mass such as brass.

As shown in fig. 4 and 5B, the main mirror balancer 410 is disposed on the right side (the other side) of the main mirror frame 100 a. The main mirror balancer 410 includes a shaft portion 411 serving as a rotation center, a contact shaft 412, a main mirror angle adjusting portion 413, and a balancer weight 414, and the balancer weight 414 is made of a material having a large mass such as brass.

In the mirror-down state, the main mirror angle adjustment portion 403 is in contact with the adjustment member 301 by the spring force of the spring 400 Sp. In addition, the state in which the contact shaft 402 is in contact with the contact plate 103 of the main mirror 100 is held by the spring force of the mirror-down spring 100 Sp. Similarly, in the mirror-down state, the main mirror angle adjusting part 413 is in contact with the adjusting member 420 by the spring force of the spring 410 Sp. In addition, the state in which the contact shaft 412 is in contact with the contact plate 104 of the main mirror 100 is maintained by the spring force of the mirror-down spring 100 Sp.

The adjustment member 301 has an eccentric shaft. Accordingly, by rotating the adjustment member 301 with a tool, the main mirror balancer 400 rotates about the shaft portion 401, whereby the contact position between the contact shaft 402 and the contact plate 103 of the main mirror 100 is changed.

Similarly, the adjustment member 420 has an eccentric shaft. Accordingly, by rotating the adjustment member 420 with a tool, the main mirror balancer 410 rotates about the shaft portion 411, whereby the contact position between the contact shaft 412 and the contact plate 104 of the main mirror 100 is changed.

In this way, the angle of the main mirror frame 100a about the hinge shaft portion 101 and the tilt of the main mirror frame 100a in the left-right direction can be adjusted.

The sub-mirror 200 is held by the sub-mirror frame 200a so as to be rotatable about a rotation center located on a side surface of the main mirror frame 100 a. Contact portions 201 and 202 are formed on the left and right sides of the sub-mirror frame 200a, respectively.

As shown in fig. 4 and 5A, the sub-mirror balancer 500 is disposed on the left side (one side) of the sub-mirror frame 200 a. The sub-mirror balancer 500 includes a shaft portion 501 serving as a rotation center for the sub-mirror balancer 500, a contact shaft 502, an adjustment portion 503, and a sub-mirror lock lever 504, and the sub-mirror lock lever 504 is provided with a lock pin 505. The contact shaft 502 serves as a mirror contact member, the sub-mirror lock lever 504 serves as a bounce restriction member, and the sub-mirror balancer 500 serves as a rotation member.

In the mirror-down state, the adjustment portion 503 of the sub-mirror balancer 500 is in contact with the adjustment member 313 by the spring force of the spring 500 Sp. The spring 500Sp serves as a biasing member. The state in which the contact shaft 502 is in contact with the contact portion 201 of the sub-mirror frame 200a is held by the spring force of a sub-mirror spring (not shown).

As shown in fig. 4 and 5B, the sub-mirror balancer 510 is disposed on the right side (the other side) of the sub-mirror frame 200 a. The sub-mirror balancer 510 includes a shaft portion 511 serving as a rotation center for the sub-mirror balancer 510, a contact shaft 512, an adjustment portion 513, and a sub-mirror lock lever 514, the sub-mirror lock lever 514 being provided with a lock pin 515. The contact shaft 512 serves as a mirror contact member, the sub-mirror lock lever 514 serves as a bounce restriction member, and the sub-mirror balancer 510 serves as a rotation member.

In the mirror-down state, the adjusting portion 513 of the sub-mirror balancer 510 is in contact with the adjusting member 520 by the spring force of the spring 510 Sp. The spring 510Sp serves as a biasing member. The state where the contact shaft 512 is in contact with the contact portion 202 of the sub-mirror frame 200a is held by the urging force of a sub-mirror spring (not shown).

In the balancer mechanism located on the left side of the sub-mirror frame 200a shown in fig. 4 and 5A, the contact shaft 502 that contacts the contact portion 201 of the sub-mirror frame 200a has an eccentric shaft. In other words, the contact shaft 502 is rotatably mounted to the sub-mirror balancer 500, but the center of rotation of the contact shaft 502 is offset from the center of the outer peripheral portion 502a (see fig. 6) of the contact shaft 502. Therefore, in particular, the radius (distance) of the outer peripheral portion 502a from the rotation center changes such that the maximum radius on one side is longer than the maximum radius on the opposite side.

Therefore, by rotating the contact shaft 502 relative to the sub-mirror balancer 500, the contact position between the outer peripheral portion 502a of the contact shaft 502 and the contact portion 201 of the sub-mirror frame 200a is changed. With this mechanism, the angle of the sub-mirror 200 in the mirror-down state can be adjusted.

In addition, the sub-mirror lock lever 504 is rotatable with respect to a cylindrical portion 502b (see fig. 6) of the contact shaft 502. The cylindrical portion 502b is eccentric with respect to the rotation center of the contact shaft 502, like the outer peripheral portion 502a of the contact shaft 502. The outer peripheral portion 502a of the contact shaft 502 serves as a first eccentric portion, and the cylindrical portion 502b of the contact shaft 502 serves as a second eccentric portion.

Therefore, even when the angle of the sub-mirror 200 is adjusted by rotating the contact shaft 502 relative to the sub-mirror balancer 500, the size of the gap at which the bounce of the sub-mirror 200 is to end does not change. In other words, the bounce restriction range does not change according to the mirror-down position of the sub-mirror 200.

In the balancer mechanism located on the right side of the sub-mirror frame 200a shown in fig. 4 and 5B, the contact shaft 512 that contacts the contact portion 202 of the sub-mirror frame 200a is formed as a shaft that is not rotatable with respect to the sub-mirror balancer 510. The adjustment member 520 has an eccentric cylindrical portion 520a, and the eccentric cylindrical portion 520a is eccentric with respect to the rotational center of the adjustment member 520. The adjustment portion 513 of the sub-mirror balancer 510 is in contact with the eccentric cylindrical portion 520 a.

Therefore, by rotating the adjustment member 520, the sub-mirror balancer 510 rotates about the shaft portion 511, and the contact position between the contact shaft 512 and the contact portion 202 of the sub-mirror frame 200a is changed. With this mechanism, the angle of the sub-mirror 200 in the mirror-down state can be adjusted.

In addition, the sub-mirror lock lever 514 is rotatable with respect to the contact shaft 512. Therefore, even when the contact position between the contact (positioning) shaft 512 and the contact (positioning) portion 202 of the sub-mirror frame 200a is changed by rotating the adjustment member 520, the size of the gap between the lock pin 515 and the contact portion 202 of the sub-mirror frame 200a does not change.

Thus, even when the angle of the sub-mirror 200 is adjusted by rotating the adjustment member 520, the size of the gap at which the bounce of the sub-mirror 200 is to end does not change. In other words, the bounce state does not change according to the mirror-down position of the sub-mirror 200.

In the present embodiment, the structures and shapes of the balancer mechanisms located on the left and right sides of the main mirror 100 and the sub mirror 200 are different from each other. The balancer mechanism located on the right side of the sub-mirror frame 200a in the present embodiment may be provided on the left side of the sub-mirror frame 200a, and the balancer mechanism located on the left side of the sub-mirror frame 200a in the present embodiment may be provided on the right side of the sub-mirror frame 200 a.

In the present embodiment, the shaft 401 serving as the rotation shaft of the main mirror balancer 400 and the shaft 411 serving as the rotation shaft of the main mirror balancer 410 are disposed in a coaxial relationship. In other words, the main mirror balancer 400 and the main mirror balancer 410 are configured such that the shaft portion 401 and the shaft portion 411 are coaxially positioned.

The shaft portion 501 serving as the rotation axis of the sub-mirror balancer 500 and the shaft portion 511 serving as the rotation axis of the sub-mirror balancer 510 are arranged in a coaxial relationship. In other words, the sub-mirror balancer 500 and the sub-mirror balancer 510 are configured such that the shaft portion 501 and the shaft portion 511 are coaxially positioned.

With this configuration, it is easier to design a mirror driving mechanism that makes the moments of inertia of the main mirror balancers 400 and 410 on the left and right sides of the main mirror 100 equal to each other. It is also easier to design a mirror driving mechanism such that the moments of inertia of the sub-mirror balancers 500 and 510 on the left and right sides are equal to each other.

Also, even when the moments of inertia of the two main mirror balancers on the left and right sides of the main mirror 100 are made different from each other, or even when the moments of inertia of the two sub mirror balancers on the left and right sides of the sub mirror 200 are made different from each other, the difference between the moments of inertia can be easily determined.

Fig. 6 is an exploded perspective view showing details of the balancer mechanism located on the left side of the sub-mirror frame 200a in fig. 4.

The contact shaft 502 includes an (eccentric) outer peripheral portion 502a that contacts the contact portion 201 of the sub-mirror frame 200a, and an (eccentric) cylindrical portion 502b that is inserted into and penetrates an engagement hole 504a of the sub-mirror lock lever 504. The eccentric amount of the outer peripheral portion 502a with respect to the rotational center of the contact shaft 502 is substantially equal to the eccentric amount of the cylindrical portion 502b of the contact shaft 502 with respect to the rotational center of the contact shaft 502. Therefore, the change in the radius from the rotational center of the outer peripheral portion 502a is substantially the same as the change in the radius from the rotational center of the cylindrical portion 502b, so that the point of the outer peripheral portion 502a where the radius from the rotational center is largest and the point of the cylindrical portion 502b where the radius from the rotational center is largest are aligned in the direction of the rotational axis. Thus, in a particular embodiment, the outer peripheral portion 502a and the cylindrical portion 502b are preferably coaxially mounted cylindrical portions of substantially the same diameter, and the offset of the center of rotation from the geometric center is substantially the same for the outer peripheral portion 502a and the cylindrical portion 502 b.

As shown in fig. 6, the sub-mirror lock lever 504, the washer W1, the sub-mirror balancer 500, and the washer W2 are sequentially mounted to the contact shaft 502, and the tip of the contact shaft 502 is crimped (crimped). Thus, the sub-mirror lock lever 504 is held between the contact shaft 502 and the sub-mirror balancer 500. In this state, the cylindrical portion 502b of the contact shaft 502 contacts the inner circumferential surface of the engagement hole 504a of the sub-mirror lock lever 504.

Since the washer W1 is disposed between the sub-mirror lock lever 504 and the sub-mirror balancer 500, the sub-mirror lock lever 504 can smoothly rotate around the cylindrical portion 502 b. In addition, since the washer W2 is disposed on the right side of the sub-mirror balancer 500 as viewed in fig. 6, the contact shaft 502 can rotate relative to the sub-mirror balancer 500 even after the tip of the contact shaft 502 is crimped.

The torsion coil spring 500Sp is disposed on the shaft 501 of the sub-mirror balancer 500, and the shaft 501 serves as the rotation center of the sub-mirror balancer 500. The movable end of the torsion coil spring 500Sp is held against a locking pin 505 fixed to the locking lever 504, and the locking lever 504 can rotate about the contact shaft 502 as a rotation center.

Thereby, the sub-mirror locking lever 504 is urged by the spring force of the torsion coil spring 500 Sp.

The tip of the contact shaft 502 is formed in a grooved shape (see, for example, fig. 7). The angle of the sub-mirror 200 is adjusted by inserting a tool such as a screwdriver into a groove formed at the tip of the contact shaft 502 and by rotating the contact shaft 502.

The operation of the balancer mechanism located on the left side of the sub mirror frame 200a in fig. 4 will be described below with reference to fig. 7, 8A, and 8B.

As described above, the torsion coil spring 500Sp is disposed on the shaft portion 501 serving as the rotation center of the sub-mirror balancer 500. The fixed end of the torsion coil spring 500Sp is held against a fixing portion (not shown), and the movable end of the torsion coil spring 500Sp is held against a locking pin 505 fixed to the locking lever 504.

The spring force of the torsion coil spring 500Sp is represented by force F in fig. 7. The force F is decomposed (resolved) into a component force F1 in a direction perpendicular to the rotational direction of the sub-mirror lock lever 504 and a component force F2 in a direction orthogonal to the component force F1, according to the contact angle between the lock pin 505 and the movable end of the torsion coil spring 500 Sp. The torsion coil spring 500Sp is set such that a component force F1, which is a force to rotate the sub-mirror balancer 500, is greater than a component force F2, i.e., F1 > F2, where a component force F1 acts as a force to rotate the sub-mirror locking lever 504 and a component force F2 acts as a force to rotate the sub-mirror locking lever 504.

The force component F1 provides a load when the kinetic energy of the secondary mirror frame 200a is transferred to the secondary mirror balancer 500. Thereby, even when the moment of inertia of the sub-mirror balancer 500 cannot be set too large, the collision energy of the sub-mirror frame 200a can be absorbed by the load provided by the spring force of the torsion coil spring 500 Sp.

The component force F2 is a spring force applied to the secondary mirror locking lever 504. The component force F2 is used not only to provide a load when the lock pin 505 comes into contact with the contact portion 201 of the sub-mirror frame 200a, but also to return the sub-mirror lock lever 504 to the rebound restricting position when the contact portion 201 of the sub-mirror frame 200a rebounds from the contact shaft 502 after passing over the lock pin 505.

Fig. 8A shows a state before the mirror-down operation is completed, that is, a state immediately before the lock pin 505 comes into contact with the contact portion 201 of the sub-mirror frame 200 a. When contact portion 201 is in contact with locking pin 505, locking pin 505 rotates and contact portion 201 then contacts contact shaft 502.

The collision energy generated at this time is converted into energy for rotating the sub-mirror balancer 500, so that the sub-mirror balancer 500 rotates as shown in fig. 8B. The lock pin 505 also rotates together with the sub-mirror balancer 500 so that the lock pin 505 can achieve rebound restriction at all times when the contact portion 201 of the sub-mirror frame 200a rebounds.

If the external size of the sub-mirror balancer 500 is increased, a problem of interference with other components may occur. In view of this problem, the sub-mirror balancer 500 is formed in an elongated shape extending from the shaft portion 501 serving as the rotation center of the sub-mirror balancer 500 to the adjustment portion 503 in only one direction. Thereby, the contact shaft 502 can effectively function as a balancer weight. In other words, in one embodiment, an angle formed by a contact point between the contact shaft 502 and the contact portion 201 and a contact point between the adjustment portion 503 and the adjustment member 313 with respect to the rotation center of the sub-mirror balancer 500 is set to be not more than 90 °.

When the sub-mirror 200 is displaced to the mirror-down state, the sub-mirror 200 rotates in a direction approaching the image pickup plane. Therefore, the sub-mirror balancers 500 and 510 also move in the direction toward the imaging plane. As shown in fig. 1, the shutter device 12 is arranged immediately in front of the image pickup element 13. Thus, there is a risk that the sub-mirror balancers 500 and 510 may interfere with the shutter device 12 in the balancing operation.

Fig. 9 is a front view of the shutter device 12. As shown in fig. 9, recesses 12b and 12c are formed in a plate disposed on the object side of the shutter device 12, thereby allowing movement of the sub-mirror balancers 500 and 510. This configuration can increase the amount of energy absorbed by the sub-mirror balancers 500 and 510, and can provide a satisfactory mechanism for absorbing the bounce of the sub-mirror 200. The recesses 12b and 12c may have a hole shape that provides similar advantageous effects even when formed continuous with the photographic opening 12 a.

Fig. 10A to 10C are explanatory views showing a detailed structure of the mirror box. Fig. 10A is a front perspective view of the mirror box, and fig. 10B is a rear perspective view of the mirror box. Fig. 10C is a rear perspective view illustrating a state in which the shutter device 12 illustrated in fig. 9 is mounted to the mirror box.

The mirror driving mechanisms shown in fig. 2A to 2C are disposed on both sides of the mirror box, and the mirror charge mechanism 31 and the mirror charge motor 30 are disposed on one side of the mirror driving mechanism.

In the present embodiment, when the camera is viewed from the rear side, the mirror charge mechanism 31 and the mirror charge motor 30 are arranged on the left side with respect to the optical axis, and the shutter device 12 and the shutter charge motor 20 are arranged on the right side of the optical axis.

A method for adjusting the main mirror 100 and the sub-mirror 200 will be described below.

The rotating shaft 101 of the main mirror 100 is positioned such that the rotating shaft 101 on the left side is engaged into a hole formed in the base plate 300 of the mirror driving mechanism and the rotating shaft 101 on the right side is fitted to the adjusting plate 105 (see fig. 10B). The position of the rotation shaft 101 of the main mirror 100 on the right side can be adjusted by adjusting the position of the adjustment plate 105.

In the above description, the angle of the main mirror 100 in its rotational direction is determined by the contact shaft 402 contacting the contact plate 103 of the main mirror 100 and by the contact shaft 412 contacting the contact plate 104 of the main mirror 100. More precisely, however, the contact between the contact shaft 402 and the contact plate 103 of the main mirror 100 and the contact between the contact shaft 412 and the contact plate 104 of the main mirror 100 do not occur simultaneously.

In other words, when the main mirror 100 is displaced to the mirror-down state, at the time of establishing either one of the contact between the contact shaft 402 and the contact plate 103 of the main mirror 100 and the contact between the contact shaft 412 and the contact plate 104 of the main mirror 100, the contact between the contact plate and the contact shaft relating to the other party is not established yet and a gap remains between the contact plate and the contact shaft.

More specifically, a plane is determined by contact at three points. In the present embodiment, the plane of the main mirror 100 when the main mirror 100 is displaced to the mirror-down state is determined by contact at three points: the three points are provided by two bearing portions that support the rotating shaft 101 of the main mirror 100, and one of the contact shaft 402 and the contact shaft 412.

In the present embodiment, the contact plate 103 of the main mirror 100 is brought into contact with the contact shaft 402 at an early timing, where the contact plate 103 is positioned on the left side where the adjustment of the position of the rotating shaft 101 of the main mirror 100 cannot be performed. Thereafter, the contact plate 104 of the main mirror 100 is brought into contact with the contact shaft 412, with the contact plate 104 positioned on the right side, and the position of the rotating shaft 101 of the main mirror 100 can be adjusted according to the position of the adjustment plate 105 on the right side.

With this configuration, the angle of the main mirror 100 in the rotational direction of the main mirror 100 can be adjusted with reference to the side of the main mirror 100 on which the rotational shaft 101 is fixedly held. If the angle of the main mirror 100 in the rotational direction of the main mirror 100 is adjusted with reference to the side of the main mirror 100 on which the rotational shaft 101 is movable, this means that the angle of the main mirror 100 in the rotational direction of the main mirror 100 is adjusted with reference to the side including the error. In other words, an error related to the position of the rotational shaft 101 of the main mirror 100 affects the angle of the main mirror 100 in the rotational direction of the main mirror 100.

Similarly to the above description, the angle of the sub-mirror 200 in the rotational direction of the sub-mirror 200 is determined by the contact shaft 502 contacting the contact portion 201 of the sub-mirror frame 200a and by the contact shaft 512 contacting the contact portion 202 of the sub-mirror frame 200 a.

More precisely, however, the contact between the contact shaft 502 and the contact portion 201 of the sub-mirror frame 200a and the contact between the contact shaft 512 and the contact portion 202 of the sub-mirror frame 200a do not occur simultaneously. In other words, when the sub-mirror 200 is displaced to the mirror-down state, at the time of establishing either one of the contact between the contact shaft 502 and the contact portion 201 of the sub-mirror frame 200a and the contact between the contact shaft 512 and the contact portion 202 of the sub-mirror frame 200a, the contact between the contact plate and the contact shaft relating to the other one is not established yet and a gap remains between the contact plate and the contact shaft.

In the present embodiment, the plane of the sub-mirror 200 when the sub-mirror 200 is displaced to the mirror-down state is determined by contact at three points: the three points are provided by two bearing portions that support the rotating shaft of the sub-mirror 200, and one of the contact shaft 502 and the contact shaft 512.

In the present embodiment, the contact shaft 512 contacts the contact portion 202 of the sub-mirror frame 200a, and the contact portion 202 and the contact shaft 512 are located on the right side of the main mirror 100 where the angle of the main mirror 100 in the rotational direction thereof is not fixedly set. On the other hand, the contact portion 201 of the sub-mirror frame 200a does not contact the contact shaft 502, and the contact portion 201 and the contact shaft 502 are located on the left side of the main mirror 100 where the angle of the main mirror 100 in the rotational direction thereof is fixedly set.

Thus, in the present embodiment, the mechanism for defining the plane of the sub mirror 200 when the sub mirror 200 is displaced to the mirror-down state and the mechanism for defining the plane of the main mirror 100 when the main mirror 100 is displaced to the mirror-down state are positioned in a diagonal relationship.

A force acting on the main mirror 100 to tilt the main mirror 100 is generated during a period from a timing when the main mirror 100 is in contact with the main mirror balancer 400 located on the left side to a timing when the main mirror 100 is in contact with the main mirror balancer 410 located on the right side.

Similarly, a force acting on the sub mirror 200 to tilt the sub mirror 200 is generated in a period from a timing at which the sub mirror 200 is in contact with the sub mirror balancer 510 located on the right side to a timing at which the sub mirror 200 is in contact with the sub mirror balancer 500 located on the left side. However, since the force acting on the main mirror 100 to tilt the main mirror 100 and the force acting on the sub mirror 200 to tilt the sub mirror 200 are opposite to each other in direction, the positioning accuracy of the main mirror 100 and the sub mirror 200 is improved.

In addition, in the present embodiment, the main mirror 100 first contacts the main mirror balancer 400 located on the left side, and then contacts the main mirror balancer 410 located on the right side. On the other hand, the sub-mirror 200 first contacts the sub-mirror balancer 510 located on the right side, and then contacts the sub-mirror balancer 500 located on the left side.

As a result, the shocks generated when the main mirror 100 and the sub-mirror 200 are shifted to the mirror-down state can be dispersed to the left and right sides, and the shocks can be ended in a short time.

The present invention has been described in detail above with reference to embodiments. The embodiments of the present invention have been described in connection with a single-lens reflex digital camera in which a lens is exchangeable, for example, but the present invention can also be implemented in the following structure: the camera body and the lens are integrated with each other and the lens cannot be replaced.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims (3)

1. A camera, comprising:

a mirror;

a mirror contact member with which the mirror is contactable; and

a bounce restriction member including a bounce restriction portion with which the mirror is contactable when the mirror bounces from the mirror contact member;

it is characterized in that the preparation method is characterized in that,

the camera further includes a rotating member configured to: the rotating member rotates when the mirror and the mirror contact member contact each other,

wherein the mirror contact member is provided to the rotating member so as to be rotatable about a rotation center,

the lens contact member includes a first eccentric portion that is eccentric with respect to the rotation center of the lens contact member and a second eccentric portion that is eccentric with respect to the rotation center of the lens contact member by an eccentric amount that is the same as that of the first eccentric portion,

when the mirror is displaced to a mirror-down state, the mirror is in contact with the first eccentric portion,

the runout restriction member is disposed to the rotation member rotatably about the second eccentric portion.

2. The camera according to claim 1, wherein the bounce limiting member is held between the mirror contact member and the rotation member.

3. The camera according to claim 1 or 2, characterized in that the camera further comprises:

a biasing member configured to bias the rotating member,

wherein the urging member urges the rotating member in a direction opposite to a rotating direction of the rotating member when the mirror and the mirror contact member are in contact with each other,

the urging member urges the bounce restricting member.