JP2016085280A - Blade driving device, light-amount adjustment device and imaging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blade driving device, light-amount adjustment device and imaging device that allow a plurality of blades to be stably driven.SOLUTION: A blade driving device comprises: a drive ring 3 that rotates around a light passage route to cause a plurality of blades 4 to be moved in the light passage route; and a holding substrate (a base plate 1 and a cover plate 2) that rotatably holds the drive ring 3 with the drive ring 3 sandwiched from either side of an optical axis direction. In the holding substrate, provided are support sections (2b, 2c and 2d) that support an outer peripheral edge part of one side of the optical axis direction of the drive ring 3 in the optical axis direction, and a rotation limit section (cam groove 1e) that engages with the drive ring 3 on the other side of the optical direction of the drive ring 3 to limit a rotation direction of the drive ring 3, in which a part having the drive ring 3 subjected to the rotation limit by the rotation limit section is provided in a range 8 substantially surrounded by the support section.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a blade driving device for driving a plurality of blades, a light amount adjusting device including the blade driving device, and an imaging device such as a camera including the light amount adjusting device.

  2. Description of the Related Art Conventionally, a camera diaphragm device having a configuration in which a plurality of diaphragm blades are rotationally driven by a diaphragm ring is known (see Patent Document 1). The camera diaphragm device of Patent Document 1 employs a structure in which a diaphragm ring is rotatably held between a ground plane and a cover board.

JP 2005-284102 A

  Here, in the conventional diaphragm device for a camera, in a configuration in which the drive ring is rotatably held between the ground plate and the cover plate, a stable operation of the blades by the drive ring is necessary.

  The present invention provides a blade driving device, a light amount adjusting device, and a photographing device capable of stably driving a plurality of blades.

  In the present invention, a drive ring that rotates around the light passage path and moves a plurality of blades in the light passage path, and a holding substrate that rotatably holds the drive ring from both sides in the optical axis direction. The holding substrate includes a support portion that supports an outer peripheral edge in one optical axis direction of the drive ring in the optical axis direction, and the drive ring is engaged with the drive ring on the other optical axis direction of the drive ring. And a rotation restricting portion for restricting the rotation direction of the drive ring, and a portion where the rotation of the drive ring is restricted by the rotation restricting portion is provided within a range substantially surrounded by the support portion. There is a blade drive device characterized in that. In this aspect of the present invention, since the rotation of the drive ring is limited within a range substantially surrounded by the support portion of the holding member that supports the drive ring, the drive ring can be stably operated. The plurality of blades can be driven stably.

  Moreover, in the said invention, the said support part is provided in three or more places in the rotation direction of the said drive ring, and the part by which the said drive ring is rotationally restricted by the said rotation restriction | limiting part carries out each of the said support part linearly. It is provided within a range surrounded by tying. In this aspect of the present invention, since the drive ring is stably supported at a plurality of locations, the stable operation of the drive ring is further enhanced.

  In the present invention, the support portion is provided at three or more locations at equal intervals in the rotation direction of the drive ring. In this aspect of the present invention, since the drive ring is stably supported at equal intervals and at three or more locations, the stable operation of the drive ring is further enhanced.

  In the present invention, the holding member includes a first substrate having an opening that forms part of a light passage path, and a second substrate that is engaged with the first substrate and provided with the support portion. The drive ring is provided with an engagement pin protruding from the first substrate side, and the engagement pin penetrates the first substrate as the rotation limiting portion. It engages with the cam groove provided by. In such an aspect of the present invention, even if an external stress is applied to the engaging pin exposed in the cam groove, the driving ring can be stably maintained in posture, so that stable operation of the driving ring can be realized. .

  In the present invention, the support part defines a space in which the plurality of blades travel between the drive ring and the holding member in the optical axis direction. In such an aspect of the present invention, the blade traveling space can be relatively easily defined by the support position of the support portion.

  In the present invention, the light amount adjusting device comprising the blade driving device, wherein the light amount is adjusted in a light passage path by a plurality of blades attached to the drive ring in the blade driving device, Alternatively, an imaging apparatus characterized by including such a blade driving device as a light amount adjusting device is also widely used. In this aspect of the present invention, since stable blade driving can be realized, it is possible to relatively easily realize a light amount adjustment device and an imaging device that can perform good light amount adjustment.

  ADVANTAGE OF THE INVENTION According to this invention, the blade | wing drive device which can drive a several blade | wing stably, a light quantity adjustment apparatus, and an imaging device can be implement | achieved comparatively easily.

FIG. 2 is a schematic plan view of a light amount adjusting device on which the blade driving device according to the first embodiment is mounted. The principal part exploded view and schematic sectional drawing of FIG. FIG. 6 is a schematic plan view of a light amount adjustment device equipped with a blade driving device according to a second embodiment. The principal part exploded view of FIG.

Hereinafter, the present invention will be described in detail based on embodiments.
<Embodiment 1>

  1 and 2 are schematic plan views of a light amount adjusting device equipped with a blade driving device according to Embodiment 1 of the present invention. FIG. 1 shows a state of the maximum aperture opening (fully opened state), and FIG. 2 shows a main part obtained by disassembling FIG.

  As shown in FIGS. 1 and 2, the blade driving device of this embodiment is a diaphragm device for a camera, and as a holding member for holding a blade driving system, a ground plate 1 serving as a first substrate, and this And a cover plate 2 that is a second substrate joined to the base plate 1. A drive ring 3 and a plurality of aperture blades 4 that are rotationally driven by the drive ring 3 are accommodated between the base plate 1 and the cover plate 2. That is, a drive system (including a blade travel space) for driving the diaphragm blades 1 is formed between the ground plate 1 and the cover plate 2.

  Specifically, the base plate 1 and the cover plate 2 are composed of synthetic resin plate-like members. Further, the circular opening 1 a provided at the center of the base plate 1 communicates with the circular opening 2 a provided at the center of the cover plate 2. Thus, when each opening part 1a and 2a communicate, the path | route (light passage path) through which a light beam passes is formed.

  Further, a concave portion 1b is formed on the surface of the base plate 1 on the cover plate 2 side so as to surround the opening 1a. And on the outer peripheral end side of the concave portion 1b of the base plate 1, six blade connecting pins 1c are formed at substantially equiangular intervals centered on the optical axis. In the recess 1b, a circular guide portion 1d is formed on the inner peripheral edge on the opening 1a side.

  Further, a drive ring 3 for driving the diaphragm blades 4 is accommodated in the recess 1b. Specifically, the drive ring 3 is accommodated in the recess 1b, and can rotate about the optical axis while the ring inner peripheral surface is in sliding contact with the guide portion 1d. In this embodiment, for example, the drive ring 3 forms a blade travel space for traveling the six diaphragm blades 4 having the same shape with the cover plate 2.

  The drive ring 3 is formed with six connecting pins 3a having a cylindrical shape at substantially equal angular intervals around the optical axis. Further, a tooth portion 3 b is provided on a part of the outer peripheral portion of the drive ring 3. A rotation stopper pin 3c is erected on the surface of the drive ring 3 on the ground plate 1 side, and the ground plate 1 is provided with a cam groove (stopper wall) 1e into which the rotation stopper pin 3c is inserted.

  Further, in the present embodiment, the diaphragm drive ring 3 described above is reciprocally rotated within a predetermined rotation angle range by a drive motor 5 such as a step motor. The drive motor 5 is attached to the main plate 1 using screws 6. A gear 7 is attached to the output shaft 5 a of the drive motor 5, and meshes with the tooth portion 3 b of the drive ring 3. The drive ring 3 of the present embodiment is configured to be reciprocally rotated by the drive motor 5, but may be reciprocally rotated manually or by other appropriate means.

  Here, the engagement structure with the base plate 1, the cover plate 2, and the drive ring 3 (and the aperture blade 4) will be described in detail with reference to FIGS.

  Each of the blade connecting pins 1 c provided on the base plate 1 is erected on the outside of the outer peripheral edge portion of the drive ring 3 at a portion deviating from the rotation region of the drive ring 3. Each of the six diaphragm blades 4 has a cam groove 4 a that engages with each connection pin 3 a of the drive ring 3 and a rotation center hole 4 b that engages with each blade connection pin 1 c of the base plate 1. doing.

  Each rotation of the diaphragm blades 4 is centered on the blade connection pins 1c erected on the main plate 1, while the connection pins 3a of the drive ring 3 are engaged with the cam grooves 4a. Further, the drive ring 3 is rotatable by connecting a gear portion of the drive motor 5 such as a stepping motor to the tooth portion 3b.

  As described above, the drive ring 3 is accommodated in the concave portion 1b of the main plate 1 and substantially abuts the inner peripheral surface of the ring on the guide portion 1d. Thereby, the movement in the surface direction of the main plate 1 is restricted by the ring inner peripheral surface being in contact with the guide portion 1d. Further, the rotation stopper pin 3c of the drive ring 3 is inserted into the cam groove 1e of the base plate 1, and the rotation of the drive ring 3 is substantially limited within a predetermined range along the cam groove 1e.

  With this configuration, in the present embodiment, each diaphragm blade 4 rotates along the cam groove 4a about each blade connection pin 1c as a rotation center when the drive ring 3 rotates within a predetermined range in one direction. And enters the light passage path (closes the light passage path). From this state, each diaphragm blade 4 rotates along the cam groove 4a around each blade connecting pin 1c as a rotation center by rotating the drive ring 3 in the reverse direction, and retreats from the light passage path (light Open the passage). In this way, the drive ring 3 is reciprocally rotated so that each diaphragm blade 4 enters and exits the light passage path, and the amount of light flux passing through the light passage path is reduced (adjusted).

  Here, the engagement configuration of the drive ring 3 in the present embodiment will be described in detail. On the blade travel space (blade chamber) side of the cover plate 2, drive ring thrust presses 2 b, 2 c, 2 d that are convex at three locations at substantially equal intervals partially support the outer peripheral edge of the drive ring 3. It is provided as a supporting part. Thereby, the position of the drive ring 3 in the thrust direction (optical axis direction) is substantially limited while sufficiently securing the travel space of the diaphragm blades 4. In the present embodiment, the drive ring 3 is stably supported by setting the thrust direction position limit of the drive ring 3 at three substantially equal intervals. In addition, each drive ring thrust holding | suppressing 2b etc. may keep a contact area small by making a contact part with the drive ring 3 into R shape. Each of the drive ring thrust retainers 2b and the like define the interval between the drive ring 3 and the cover plate 2 and the range of the blade travel direction in the blade travel space.

  In the rotation support structure of the drive ring 3, it is preferable to make the support area (contact area) in the portion supporting the drive ring 3 as small as possible in consideration of physical friction with other members. Further, when the supporting area is reduced, there is an advantage that the diaphragm blades 4 arranged around the support area can be enlarged, and a larger amount of light can be reduced. In blade driving for light quantity adjustment, since it is desired to rotate the drive ring 3 at a high speed, a structure that stably supports the drive ring 3 with a small contact area or sliding property is required. Become. Therefore, for example, in this embodiment, the drive ring thrust retainers 2b, 2c, and 2d are provided at substantially equal intervals around the optical axis, and a three-point support structure is employed. This makes it possible to stably support the disk-shaped drive ring 3 with a small contact area. Here, the structure in which the drive ring is supported by three-point support has been described. However, if three or more support portions are provided, the posture of the drive ring 3 is further stabilized.

  On the other hand, in this embodiment, in order to open and close the light passage opening using the six diaphragm blades 4, a structure in which the drive ring 3 is reciprocated within a certain range, specifically, from the drive ring 3 to the drive ring 3 is provided. A rotation limiting structure in which the rotation stopper pin 3c is inserted into the cam groove 1e of the main plate 1 is adopted.

  Therefore, the drive ring 3 is supported at three points by the drive ring thrust press 2b and the like when viewed from the cover plate 2, and the rotation is restricted by the cam groove 1e when viewed from the main plate 1. That is, the drive ring 3 has a physical engagement relationship between the main plate 1 and the cover plate 2. For this reason, in this embodiment, in order to ensure the stable drive of the drive ring 3, the engagement structure (holding structure) of the ground plane 1 and the cover board 2 was devised.

  Specifically, as shown in FIG. 2, the portion where the drive ring 3 is restricted in rotation by the cam groove (rotation limiting portion) 1e, that is, the region where the rotation stopper pin 3c is surrounded by the drive ring thrust retainers 2b, 2c and 2d. (Virtual range) Since it is arranged inside 8, for example, even if the rotation stopper pin 3c is physically pressed in a state where the rotation stopper pin 3c is in contact with the cam groove 1e, the drive ring 3 The movement in the thrust direction is substantially restricted within the travel space of the aperture drive ring 3 defined by the recess 1b of the base plate 1 and the drive ring thrust retainers 2b, 2c, 2d of the cover plate 2.

  Therefore, according to the holding structure of the drive ring 3 of the present embodiment, the holding portion (here, the cover plate 2) that supports the drive ring 3 substantially includes the support portion (here, the drive ring thrust pressers 2b, 2c, and 2d). Since the rotation limitation of the drive ring 3 is performed within the range 8 surrounded by, the drive ring 3 can be stably operated, and a plurality of blades can be stably driven.

  Further, in the present embodiment, as described above, the drive ring 3 can be driven while being stably held. Therefore, for example, in the configuration of limiting the rotation of the drive ring 3, the rotation stopper pin 3c is minimized. It is also possible to make the base plate 1 thinner by shortening it to a minimum, which is extremely advantageous for downsizing the entire apparatus in the optical axis direction.

<Embodiment 2>
3 and 4 are schematic plan views of a light amount adjusting device equipped with the blade driving device according to the second embodiment of the present invention. FIG. 3 shows the state of the maximum aperture opening (fully opened state), and FIG. 4 shows the essential parts of FIG.

  In the first embodiment described above, the structure in which the drive ring 3 is supported at three points by the drive ring thrust retainers 2b, 2c, and 2d is described as an example. However, in this embodiment, the drive thrust retainer 2e is increased by one and the drive ring is increased. 3 stable support was realized.

  As a result, as shown in FIG. 4, it is possible to expand the arrangement range of the portion where the rotation of the drive ring 3 is restricted by the cam groove (rotation limiting portion) 1 e. That is, in the present embodiment, the rotation stopper pin 3c can be disposed inside the region (virtual range) 8 surrounded by the drive ring thrust retainers 2b, 2c, 2d, and 2e. Similar effects can be obtained.

<Other embodiments>
As mentioned above, although this invention was demonstrated in detail based on Embodiment 1 and 2, this invention is not limited to Embodiment 1 and 2 mentioned above. For example, in the first and second embodiments described above, the structure in which the rotation of the drive ring 3 is limited by the base plate 1 and the drive ring 3 is supported by the cover plate 2 is exemplified. A structure in which the rotation of the drive ring 3 is limited by the cover plate 2 and the drive ring 3 is supported by the ground plate 1 may be employed.

  In Embodiments 1 and 2 described above, the drive ring 3 is held by a plurality of drive ring thrust retainers 2b or the like. For example, the drive ring 3 is provided by continuously providing a drive ring thrust retainer around the optical axis. You may support it cyclically | annularly. Even in this case, the rotation of the drive ring may be limited within a range in which the drive ring 3 is annularly supported.

  Moreover, in Embodiment 1 and 2 mentioned above, although the structure which provided the rotation stopper pin 3c in the drive ring 3 was illustrated, this invention is not limited to this of course, For example, a rotation stopper pin protrudes from a ground plane, A structure of inserting into the cam groove of the drive ring may be adopted. Thereby, for example, it is possible to realize a further high-speed drive by reducing the thickness of the drive ring.

Claims (7)

A drive ring that rotates around a light passage path and moves a plurality of blades in the light passage path;
A holding substrate that rotatably holds the drive ring from both sides in the optical axis direction,
The holding substrate includes a support portion that supports an outer peripheral edge portion in one optical axis direction of the drive ring in the optical axis direction, and engages with the drive ring on the other optical axis direction side of the drive ring. A rotation limiting portion for limiting the rotation direction of the drive ring is provided,
The blade drive device according to claim 1, wherein a portion of the drive ring whose rotation is restricted by the rotation restriction portion is provided within a range substantially surrounded by the support portion. The support portion is provided at three or more locations in the rotation direction of the drive ring,
The blade drive device according to claim 1, wherein a portion of the drive ring whose rotation is restricted by the rotation restriction portion is provided within a range surrounded by linearly connecting the support portions.   3. The blade driving device according to claim 1, wherein the support portion is provided at three or more locations at equal intervals in the rotation direction of the drive ring. The holding member includes a first substrate having an opening that forms a part of a light passage path, and a second substrate that is engaged with the first substrate and provided with the support portion.
The drive ring is provided with an engagement pin protruding from the first substrate side,
4. The blade driving device according to claim 1, wherein the engagement pin is engaged with a cam groove provided by penetrating the first substrate as the rotation restricting portion. 5. .   5. The blade according to claim 1, wherein the support portion defines a space in which the plurality of blades travel between the drive ring and the holding member in an optical axis direction. Drive device.   A blade drive device according to any one of claims 1 to 5, wherein the amount of light is adjusted in a light passage path by a plurality of blades attached to the drive ring in the blade drive device. Light quantity adjustment device to do.   An imaging apparatus comprising the blade driving device according to claim 6 as a light amount adjusting device.

Images