JP2007322846A - Mirror device and camera equipped with the mirror device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mirror device minimizing bound caused when a quick return mirror stops. <P>SOLUTION: The mirror device has a deformation reduction mechanism (15) that decrease deformation caused in the mirror member 11, mounted on swing center parts (14a) and (14b) for a mirror member (11) supported swingably in a mirror box (13). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mirror device that immediately attenuates the bounce of a mirror built in a camera, and a camera equipped with the mirror device.

  In a single-lens reflex camera, a so-called quick return mirror is disposed in a photographing optical path between an imaging lens (objective lens) and an image plane (an imaging element such as a CCD). This quick return mirror is normally at the observation position in the shooting optical path, reflects the light beam incident from the imaging lens, guides it to the viewfinder optical system, and presses the release button during shooting to interlock the observation position. To the retracted position outside the imaging optical path and return to the observation position after the shutter operation is completed. That is, the quick return mirror reciprocates between the observation position and the retracted position. In order to stop the quick return mirror at the observation position or the retracted position, the quick return mirror is caused to collide with a stop member such as a pin. For this reason, the quick return mirror itself bounces. Until this bounce is settled, it is not possible to shift to the next operation and it is necessary to wait. For example, in the case of continuous shooting, photometry and distance measurement must be waited until the bounce of the quick return mirror is settled, which is an obstacle to increasing the number of continuous shooting frames.

  In order to immediately attenuate the bounce, for example, a mechanism has been proposed in which the quick return mirror is attracted and held by an electromagnet at each of the observation position and the retracted position (Patent Document 1). In addition, a mechanism has been proposed in which a part of the mirror is applied to the buffer member immediately before the quick return mirror reaches the retracted position to reduce the kinetic energy and speed, and thereafter, it is caused to collide with the stop member and quietly stop. (Patent Document 2). Furthermore, a mechanism has been proposed in which the kinetic energy received by the quick return mirror due to the collision between the quick return mirror and the stop member is attenuated by converting it into strain energy or friction energy of the spring (Patent Document 3).

JP-A-6-175223 Japanese Patent Laid-Open No. 5-45723 JP 7-261268 A

  However, the mechanism that attracts and holds the quick return mirror with an electromagnet has a problem of increasing power consumption because a plurality of electromagnets are arranged. In addition, in the mechanism that reduces the kinetic energy by being applied to the buffer member, in addition to the durability of the buffer member, there is a problem that the buffer member deteriorates during repeated use, leading to a decrease in performance. Furthermore, the mechanism that converts the kinetic energy received by the quick return mirror into the strain energy and frictional energy of the spring is complicated, and there are problems such as difficulty in dealing with design changes and securing installation space. .

  As a result of intensive research on the bounce phenomenon itself in order to solve these problems, the present inventor caused deformation (elastic deformation) such as torsion in the quick return mirror during the bounce, and this deformation prolongs the bounce. I found out. As a result of suppressing the deformation (torsional vibration) of the quick return mirror, the occurrence of the bounce itself can be suppressed, and even if it occurs, it has been found that it is immediately attenuated, and the present invention has been made.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a mirror device that can suppress the bounce when the quick return mirror is stopped and a camera that incorporates the mirror device.

  The mirror device according to claim 1 of the present invention that achieves the above object is a deformation reduction that reduces the deformation generated in the mirror member at a swing center portion of the mirror member that is swingably supported in the mirror box. Equipped with a mechanism.

  As the deformation reducing mechanism, for example, a mechanism that reduces the deformation generated in the mirror member by reducing the impact acting on the mirror member is employed.

  The deformation generated in the mirror member includes, for example, twisting of the mirror member. Deformation is an elastic deformation caused by an impact force acting on the mirror member. When the impact force acting on the mirror member disappears, the original shape is restored. The reduction includes, for example, a case where the torsional force acting on the mirror member is absorbed and reduced.

  A mirror device according to a second aspect is the mirror device according to the first aspect, wherein the deformation reduction mechanism includes a holder provided integrally with the mirror member and provided at the swing center portion, and the swing center portion. And a rotation member that is swingably supported by the mirror box, and a deformation reduction member that is provided between the holder and the rotation member.

  Examples of the rotating member include a rotary bearing that is rotatably supported by a support shaft fixed to the mirror box, or a rotary shaft that is rotatably supported by a bearing fixed to the mirror box.

  As the deformation reducing member, for example, a member that is elastically deformed to reduce the impact is adopted.

  The mirror device according to a third aspect is characterized in that the deformation reducing member includes at least one of silicon rubber and butyl rubber.

  The mirror device according to claim 4, further comprising a stop member for stopping the swing of the mirror member, and the swing center close to the stop member among two swing center portions provided at both ends of the mirror member. The part is equipped with the deformation reducing mechanism.

  Examples of the stop member include a pin and a rod-like member that stop when the mirror member collides.

  The mirror device according to claim 5, wherein the mirror box includes two wall portions facing each other so as to swingably support the swing center portions at both ends of the mirror member, and any one of the wall portions. One of the features is that a position adjustment mechanism for supporting the swing center part of the mirror member equipped with the deformation reducing mechanism and adjusting the mounting position of the swing center part on the other side is provided.

  According to a sixth aspect of the present invention, the mirror device is characterized in that the mirror member is provided with a sub mirror that reflects the light transmitted through the mirror member so as to be swingable.

  A mirror device according to a seventh aspect is characterized in that the deformation reducing mechanism according to any one of the first to fourth aspects is provided at a swinging central portion of the sub mirror.

  A camera according to an eighth aspect is characterized in that the mirror device according to any one of the first to seventh aspects is mounted.

  According to the mirror device of the present invention, since the deformation reduction mechanism is provided at the center part of the swing of the mirror member, it is possible to suppress the bounce of the mirror member to be small without complicating the mechanism.

  According to the camera of the present invention, since the mirror device having the deformation reduction mechanism is provided at the center of swinging of the mirror member, it is possible to shorten the waiting time until the bounce of the mirror member is settled at the observation position or the retracted position. It becomes.

  Embodiments of a mirror device of the present invention and a camera equipped with the mirror device will be described below with reference to FIGS.

  FIG. 1 is a partially omitted enlarged perspective view showing an embodiment of the mirror device of the present invention, and FIG. 2 is a cross-sectional view showing an embodiment of the camera of the present invention equipped with the mirror device of FIG.

  First, the outline of the camera will be described. The camera is a digital still camera 20 and, as shown in FIG. 2, a photographing lens 22 is replaceably mounted on the front side of the body 21 (left side in FIG. 2). A CCD 23 serving as an image sensor and a shutter 24 are disposed behind the photographic lens 22 and behind the body 21 (right side in FIG. 2).

  In the space between the photographing lens 22 and the shutter 24 (CCD 23), the mirror device 10 equipped with the quick return mirror 11 and the sub mirror 12 is disposed. When the shutter 24 is closed, the quick return mirror 11 and the sub mirror 12 are at the observation position in the photographing optical path (position shown by the solid line in FIG. 2), and the quick return mirror out of the light incident through the photographing lens 22. 11 is guided to the finder optical system 26 through a prism 25 disposed above the mirror device 10 in the body 21. On the other hand, the quick return mirror 11 is a half mirror, and light transmitted through the quick return mirror 11 is reflected by the sub mirror 12 and guided to a photometry / ranging unit (not shown). When a shutter button (not shown) is pressed and the shutter 24 is opened in conjunction with this, the quick return mirror 11 and the sub mirror 12 move from the observation position to the retracted position outside the photographing optical path (the two-dot chain line position in FIG. 2). The light incident through the photographing lens 22 forms an image on the CCD 23. After the shutter operation is completed, the quick return mirror 11 and the sub mirror 12 return to the observation position.

  The mirror device 10 includes the quick return mirror 11 and the sub mirror 12 described above, and a mirror box 13 that supports the quick return mirror 11 in a swingable manner. As described above, the quick return mirror 11 swings between the observation position and the retracted position and guides the light incident through the photographing lens 22 to the finder optical system 26 or the CCD 23. The unit 11b is provided. The mirror part 11b is integrated with an adhesive so as to cover the opening of the mirror holder part 11a. The reason why the mirror holder portion 11a is provided with an opening is to guide the light transmitted through the mirror portion 11b to the sub mirror 12. At the upper ends (bases) on both sides of the mirror holder portion 11a, swing center portions 14a and 14b that are swingably supported by wall portions 13a and 13b facing each other of the mirror box 13 are provided. A deformation reducing mechanism 15 is provided in each of the swinging central portions 14a and 14b.

  Since the deformation reduction mechanism 15 provided in the rocking center part 14a and the deformation reduction mechanism 15 provided in the rocking center part 14b have the same configuration, in the following description, the deformation reduction mechanism 15 provided in the rocking center part 14a will be described. The description of the deformation reducing mechanism 15 provided in the oscillation center portion 14b is omitted.

  The deformation reduction mechanism 15 reduces the impact applied to the mirror holder portion 11a, suppresses the occurrence of elastic deformation (for example, twist) generated in the mirror holder portion 11a itself, and reduces this elastic deformation. As shown, the ring-shaped holder 15a formed integrally with the swing center portion 14a of the mirror holder portion 11a and the swing center portion 14a of the mirror holder portion 11a are provided on the wall portion 13a of the mirror box 13. Rotating bearing 15b as a rotating member supported by a fixed support shaft 13c so as to be swingable, and made of silicon rubber as a deformation reducing member inserted in a compressed state into a space between these holder 15a and rotating bearing 15b Ring 15c.

  As shown in FIG. 3, the holder 15a has an inner diameter set so as to receive the rotary bearing 15b and the ring 15c concentrically, and its axial dimension is slightly larger than the axial dimension of the rotary bearing 15b and the ring 15c. Set short.

  As shown in FIG. 3, the rotary bearing 15 b has a flange 151 b integrally formed at the end on the wall 13 a side, and one side surface of the flange 151 b is rotatably contacted with the wall 13 a. The inner peripheral surface of the rotary bearing 15b is rotatably contacted with the outer peripheral surface of the support shaft 13c, and is supported rotatably on the support shaft 13c in a stable state.

  The ring 15c is in close contact with the inner peripheral surface of the holder 15a and the outer peripheral surface of the rotary bearing 15b, and absorbs the impact by elastically deforming the impact applied to the swinging central portion 14 when the quick return mirror 11 is stopped. The deformation of the quick return mirror 11 is reduced by relaxation and attenuation. In addition, although the case where it formed with the silicon rubber excellent in durability as the ring 15c was shown, you may form similarly with the butyl rubber excellent in durability.

  One wall portion 13a of the mirror box 13 that supports one swinging central portion 14a so as to be swingable is provided with a stop pin 16 as a stop member at a portion below the inner surface thereof. The stop pin 16 stops the quick return mirror 11 at the observation position when a portion of the mirror holder portion 11a on the free end side and the wall portion 13a collides. Further, a stop bar member 17 having a square cross section is provided on the inner surface upper portion of both wall portions 13a and 13b of the mirror box. The stop rod member 17 stops the quick return mirror 11 at the retracted position when the entire surface on the free end side of the mirror holder portion 11a collides. The stop rod member 17 is configured, for example, by arranging a metal core rod at the center and covering the outer peripheral surface with urethane foam or the like that reduces the impact at the time of collision of the mirror holder portion 11a.

  As described above, the sub mirror 12 reflects the light transmitted through the mirror portion 11b of the quick return mirror 11 and guides it to the photometry / ranging unit when it is in the observation position. As shown in FIG. 2, the base portions (upper end portions) on both sides of the mirror holder portion are swingably supported by the mirror holder portion 11 a of the quick return mirror 11. On both sides of the base (upper end) of the mirror holder portion, swing center portions 19a and 19b are provided, and the swing center portions 19a and 19b are provided with a deformation reducing mechanism 150 having the same configuration as the above-described deformation reducing mechanism 15. Each is provided. When the impact received by the quick return mirror 11 (mirror holder portion 11a) is transmitted to the sub mirror 12, the deformation reducing mechanism 150 reduces the impact transmitted to the sub mirror 12, and the sub mirror 12 (mirror holder portion) itself is caused by this impact. The generation of elastic deformation (for example, twist) occurring in the case is suppressed, and this elastic deformation is reduced.

  Next, the operation of the mirror device 10 of this embodiment will be described.

  When the quick return mirror 11 moves from the observation position to the retracted position, and the entire surface on the free end side collides with the stop rod member 17 and stops at the retracted position (when the mirror is raised), or moves from the retracted position to the observation position. When a part of the free end collides with the pin 16 and stops at the observation position (when the mirror is down), the quick return mirror 11 (mirror holder portion 11a) receives an impact at each position. That is, an impact is received on the free end side of the mirror holder portion 11a when the mirror is raised, and on the free end side portion of the mirror holder portion 11a on the pin 16 side when the mirror is down. The sub mirror 12 also receives an impact applied to the mirror holder portion 11a.

  This impact is transmitted to the rocking center portions 14a and 14b, which are places restrained by the mirror box 13. The impact transmitted to the rocking center portions 14a and 14b acts on the rotary bearing 15b in the radial direction from the holder 15a integral with the mirror holder portion 11a via the ring 15c, but is absorbed and relaxed by elastic deformation of the ring 15c. Is done.

  Further, the rotary bearing 15b is inclined with respect to the support shaft 13c due to the impact, and the twist is likely to occur on the swing center portions 14a and 14b side of the mirror holder portion 11a. However, the impact is absorbed by the elastic deformation of the ring 15c as described above. The vibration that is relaxed and is transmitted to the rotary bearing 15b is slight, and the vibration caused by the twist generated on the side of the swinging center portion 14a, 14b of the mirror holder portion 11a when the rotary bearing 15b is tilted or vibrated with respect to the support shaft 13c. Pressed.

  Further, since the vibration due to torsion on the swinging center portions 14a and 14b side of the mirror holder portion 11a is suppressed, the bounce of the quick return mirror 11 is reduced.

  The sub-mirror 12 is also supported and restrained by the mirror holder portion 11a of the quick return mirror 11, and an impact is applied to the swing center portions 19a and 19b, but the deformation reduction mechanism 150 provided at the swing center portions 19a and 19b. Is alleviated as described above.

  Therefore, in the camera 20 equipped with the mirror device 10 of the present embodiment, when the quick return mirror 11 and the sub mirror 12 are moved from the retracted position to the observation position, the bounce generated in the quick return mirror 11 and the sub mirror 12 is immediately accommodated. The waiting time is shortened until the bounce is settled, and the light transmitted through the quick return mirror 11 out of the light incident through the photographing lens 22 is reflected by the sub mirror 12 without waiting too much. It can be guided to the distance measuring unit, and the number of frames for continuous shooting per unit time can be increased.

  In the above-described embodiment, the case where the deformation reduction mechanism 15 is provided in each of the oscillation center portions 14a and 14b is shown. However, the present invention is not limited to this, and the deformation reduction mechanism 15 is provided in only one of them. Also good.

  In this case, it is preferable to provide the deformation reducing mechanism 15 at one swinging central portion 14a supported by the wall portion 13a provided with the stop pin 16. This is because the swing center portion 14a is close to the portion of the mirror holder portion 11a that collides with the stop pin 16, and is subjected to a larger impact than the other swing center portion 14b at the time of the collision. If the impact is reduced here, it is possible to effectively reduce the impact acting on the entire mirror holder portion 11a.

  As described above, when the deformation reducing mechanism 15 is provided only in one of the swing center portions 14a, the other wall portion 13b of the mirror box 13 that supports the other swing center portion 14b so as to be swingable is provided on the other wall portion 13b. As shown in FIG. 4, a position adjusting mechanism 18 for adjusting the attachment position of the rocking center portion 14b to the wall portion 13b can be arranged.

  The position adjusting mechanism 18 includes a position adjusting plate 18a to which a support shaft 13c (see FIG. 1) that supports the swinging central portion 14b so as to be swingable, and a headed head that fixes the position adjusting plate 18a to the wall portion 13b. It has a screw 18b and a through hole 18c formed in the position adjusting plate 18a. The head screw 18b is screwed into a screw hole (not shown) formed in the wall portion 13b through the through hole 18c. The dimension of the through hole 18c is set slightly larger than the outer diameter of the shaft portion of the head screw 18b. Has been. Therefore, by slightly sliding the position adjusting plate 18a with respect to the wall portion 13b before the headed screw 18b is tightened into the screw hole, the position of the support shaft 13c (the swing center portion supported so as to be swingable by the support shaft 13c). 14b mounting position) can be adjusted. After the position adjustment, the head screw 18b is tightened in the screw hole to fix the position adjustment plate 18a to the wall portion 13b.

  In the above-described embodiment, the case where the deformation reduction mechanism 15 is provided with the rotary bearing 15b and the wall portions 13a and 13b are provided with the support shaft 13c that rotatably supports the rotary bearing 15b is shown, but the present invention is not limited thereto. For example, the deformation reduction mechanism 15 may be provided with a rotation shaft, and the wall portions 13a and 13b may be provided with bearings that rotatably support the rotation shaft.

It is the expansion perspective view which abbreviate | omitted partially which shows one Embodiment of the mirror apparatus of this invention. It is sectional drawing which shows one Embodiment of the camera of this invention equipped with the mirror apparatus of FIG. It is an expanded sectional view of the deformation | transformation reduction mechanism part of the mirror apparatus of FIG. It is a side view which shows another embodiment which equipped the mirror apparatus of FIG. 1 with the position adjustment mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Mirror apparatus 11 Quick return mirror 11a Mirror holder part 12 Sub mirror 13 Mirror box 14a, 14b Oscillation center part 15 Deformation reduction mechanism 15a Holder 15b Rotating member (rotating bearing) 15c Deformation reducing member (ring)
16 Stop member (stop pin) 17 Stop rod member 18 Position adjustment mechanism 19a, 19b Oscillation center portion 150 Deformation reduction mechanism

Claims (8)

  A mirror device comprising a deformation reducing mechanism for reducing deformation generated in a mirror member at a rocking center portion of a mirror member supported so as to be capable of rocking in a mirror box. The mirror device according to claim 1,
The deformation reduction mechanism is
A holder provided integrally with the mirror member and provided at the center of swinging;
A rotating member that is provided at the center of swinging and is swingably supported by the mirror box;
A mirror apparatus comprising a deformation reducing member provided between the holder and the rotating member. The mirror device according to claim 2,
The mirror device, wherein the deformation reducing member includes at least one of silicon rubber and butyl rubber. The mirror device according to any one of claims 1 to 3,
A stop member for stopping the swing of the mirror member is provided, and the deformation reducing mechanism is provided at the swing center portion close to the stop member among the two swing center portions provided at both ends of the mirror member. A mirror device characterized by that. The mirror device according to claim 4,
The mirror box includes two wall portions facing each other so as to swingably support the swing center portions at both ends of the mirror member, and one of the wall portions is equipped with the deformation reduction mechanism. A mirror apparatus, characterized in that a position adjusting mechanism for supporting a swing center part of the mirror member and adjusting an attachment position of the swing center part on the other side is provided. The mirror device according to any one of claims 1 to 5,
A mirror device, wherein the mirror member is swingably equipped with a sub-mirror that reflects light transmitted through the mirror member. The mirror device according to claim 5,
A mirror device comprising the deformation reducing mechanism according to any one of claims 1 to 4 at a rocking center portion of the sub mirror.   A camera comprising the mirror device according to any one of claims 1 to 7.

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