JP2018194672A - Blade driving apparatus and optical device - Google Patents

Abstract

To provide a blade driving apparatus which reduces occurrence of ghost.SOLUTION: A blade driving apparatus includes: an aperture forming member which forms a fixed aperture where light passes; a plurality of diaphragm blades which moves forward and backward with respect to the fixed aperture by a driving force from a driving source to form a diaphragm aperture; a driving ring arranged to surround a central axis of the fixed aperture and transmitting the driving force to the diaphragm blades by rotation; and a moving mechanism which moves the driving ring parallel to an aperture surface of the fixed aperture. When the driving ring is moved by the moving mechanism, the diaphragm aperture is moved parallel to the aperture surface.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a light-shielding structure of a photographing lens, and more particularly to a light-shielding structure of a photographing lens that removes a ghost image due to incidence of harmful light rays from outside the photographing angle of view.

  In a conventional camera, for example, a first lens group, a second lens group, a third lens group, and a fourth lens group are arranged in this order in a lens barrel, and between the third lens group and the fourth lens group. A diaphragm is arranged on the lens, and the light passing through each lens group and the diaphragm is imaged on an imaging surface such as a CCD. On the other hand, when extremely strong light such as the sun or illumination light enters from outside the field of view of the conventional photographic lens, the light is reflected from the aperture opening end face or the inner surface of the lens barrel and reaches the imaging surface. There is a problem that a ghost occurs. In order to prevent harmful rays that cause such ghosts from entering the imaging surface, conventional imaging lenses have a light blocking structure to reduce the aperture diameter of the aperture and lens frame, and to block harmful light. I do.

JP-A-8-234072 JP-A-8-334725

  However, if a light shielding structure is provided in the optical path as in the photographing lens disclosed in Patent Document 1, the effective area of the lens when the aperture is opened is affected. Further, as in the photographing lens disclosed in Patent Document 2, if the aperture diameter is made small, a part of the light passing area necessary for photographing is shielded widely. This unnecessarily reduces the effective aperture of the lens, that is, the F-number when the aperture is opened is unnecessarily increased.

  SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and includes an imaging lens blade driving device that prevents the occurrence of ghosts caused by harmful rays incident from outside the imaging angle of view without reducing the effective aperture diameter, and the same. It is an object to provide an optical device.

In view of the above problems, the blade driving device according to the present invention is
An opening forming member that forms a fixed opening through which light passes;
A plurality of aperture blades that form an aperture opening by moving forward and backward with respect to the fixed aperture by a driving force from a drive source;
A drive ring that is disposed so as to surround the central axis of the fixed opening, and that transmits the driving force to the plurality of diaphragm blades by a rotation operation;
A moving mechanism for moving the drive ring in parallel with the opening surface of the fixed opening,
By moving the drive ring by the moving mechanism, the aperture opening is moved in parallel with the opening surface.

  According to this configuration, in the process of changing from the full aperture to the small aperture, a part of the optical path through which harmful light that causes ghosts can be shielded to reduce ghosts.

The disassembled perspective view of the blade | wing drive device which concerns on Embodiment 1 of this invention. The other disassembled perspective view of the blade | wing drive device which concerns on Embodiment 1 of this invention. The front view and back view which show the change of the aperture opening of the blade | wing drive device which concerns on Embodiment 1 of this invention. The front view which shows the change of the aperture opening of the blade | wing drive device which concerns on Embodiment 1 of this invention (no cover, 1 blade | wing). Sectional drawing of the imaging lens of the optical instrument provided with the blade | wing drive device which concerns on Embodiment 1 of this invention. Sectional drawing of the imaging lens of the optical instrument provided with the blade | wing drive device which concerns on Embodiment 1 of this invention. Sectional drawing of the imaging lens of the optical instrument provided with the blade | wing drive device which concerns on Embodiment 1 of this invention. The disassembled perspective view of the blade | wing drive device which concerns on Embodiment 2 of this invention. The other disassembled perspective view of the blade | wing drive device which concerns on Embodiment 2 of this invention. The front view and back view which show the change of the aperture opening of the blade | wing drive device which concerns on Embodiment 2 of this invention. The front view and back view which show the change of the aperture opening of the blade | wing drive device which concerns on Embodiment 3 of this invention. The disassembled perspective view of the blade drive device which concerns on Embodiment 4 of this invention. The front view and back view which show the change of the aperture opening of the blade | wing drive device which concerns on Embodiment 4 of this invention. The disassembled perspective view of the blade | wing drive device which concerns on Embodiment 5 of this invention. The other disassembled perspective view of the blade | wing drive device which concerns on Embodiment 5 of this invention. The front view and back view which show the change of the aperture opening of the blade | wing drive device which concerns on Embodiment 5 of this invention. Schematic of the optical apparatus which concerns on Embodiment 6 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Embodiment 1>
1 and 2 are exploded perspective views of the blade driving device according to the first embodiment of the present invention. The blade driving device according to the present embodiment is provided in a lens barrel of an optical device or the like, and adjusts the amount of light incident on the image sensor of the optical device.

  FIG. 1 shows a base member 202 in which a fixed opening 202a serving as a light passage opening 200a is formed at the center. The direction in which the light beam passes through the light passage opening is referred to as the optical axis direction, and the optical axis passing through the center of the lens barrel or the like in which the blade driving device is disposed is the optical axis center. The base member 202 is provided with a plurality of protruding engaging portions 202b for engaging with a drive ring 205, which will be described later, around the fixed opening 202a. Further, the base member 202 is provided with a plurality of convex portions 202c for restricting movement of a drive ring 205, which will be described later, in the optical axis direction. In the present embodiment, the convex portion 202 c is formed in a hemispherical shape, and its top portion is in sliding contact with the surface of the drive ring 205 on the base member 202 side that is orthogonal to the optical axis direction.

  The annular drive ring 205 is provided with an engagement portion 205a for engaging the plurality of engagement portions 202c of the base member 202 described above, and the movement in the radial direction is restricted. To rotate around the center of the optical axis. Further, a receiving portion 205b that is in contact with the convex portion 202c of the base member 202 described above and is restricted from moving on the base member side in the optical axis direction is provided. In addition, a surface portion 205c that comes into contact with a convex portion 206b of a cover member 206, which will be described later, is provided, and movement to the cover member 206 side in the optical axis direction is restricted. In this way, the drive ring 205 has a structure for reducing sliding friction with the base member 202 and the cover member 206, and is disposed so as to surround a central axis of a fixed opening 202a provided in the frame member 201 described later. Has been.

  Further, the drive ring 205 is provided with drive holes 205d to 205l for engaging with each of a plurality of first drive pins 204d to 204l of the diaphragm blade 204 described later to drive the diaphragm blade 204. The blades 204 are driven in conjunction with each other. The drive ring 205 is provided with a gear-shaped portion that is a driven portion 205m. A pinion 207a (driving gear), which will be described later, and gear teeth mesh with each other at the first meshing position, and when the pinion 207a rotates, a driving force is transmitted to the driven portion 205m, and the driving ring 205 rotates.

  The drive ring 205 is provided with a light shielding portion 205n, and enters and exits a light emitting / receiving portion of a PI (photo interrupter) 209 fixed to the PI fixing portion 202d of the base member 202, and detects the rotational position of the drive ring 205. It serves as a sensor. In particular, it is used to check whether the blade is open.

  The surface portion 205c of the drive ring 205 is a sliding contact surface of the diaphragm blade 204, which will be described later, while the convex portion 206b of the cover member 206 slides, and restricts the movement of the diaphragm blade 204 toward the drive ring 205 in the optical axis direction. doing. In the present embodiment, the drive ring 205 is created by resin molding. In addition, for example, it may be created by pressing a resin film (PET sheet material or the like). In the case of processing by press working, since it can be formed with higher accuracy than the shape accuracy of resin molding, it is possible to increase the drawing accuracy. As the thickness of the resin film, it is preferable to use a material having a thickness of 0.03 mm to 0.30 mm. By reducing the thickness as much as possible, the inertia during rotation can be reduced, and the diaphragm device can be operated at high speed. The drive ring 205 is supported by the base member 202 and the cover member 206 so as to be optimally movable in both the optical axis direction and the radial direction, so that deformation of the drive ring 205 can be minimized even if the thickness is reduced. Can do.

  Further, when a convex shape is formed on the drive ring 205 of the resin film, the convex portion may be attached by insert molding, or may be attached by press-fitting, adhesion or the like. The drive ring 205 may be made of a material that is surface-treated on one side or both sides. Examples of the surface treatment include sliding coating, antistatic treatment, and antireflection treatment. By sliding coating, friction with the base member 202, which is a component that slides with the drive ring, diaphragm blades 204 and a cover member 206, which will be described later, can be reduced, and power-saving operation is possible. Further, by performing the antireflection treatment, it is possible to suppress the reflection of the light that has entered the blade driving device, and to prevent the occurrence of ghost, flare, etc. when the light amount adjusting device is incorporated in the lens barrel. .

  The aperture blade 204 is an aperture blade 204 in which first drive pins 204d to 204l and second drive pins 204m to 204u are provided on the blade material 204v. The blade material referred to here is produced by, for example, pressing a resin film (PET sheet material or the like). The blade material may be a thin metal plate. The first drive pin and the second drive pin are made of a resin material by injection molding, and the blade member 204v and the drive pin are integrated by outsert molding. The drive pin may be a metal, or may be integrated by adhesion or caulking. The blade member 204v and the drive pin can be integrated with resin by injection molding.

  In the diaphragm blade 204, first drive pins 204d to 204l are respectively engaged with drive holes 205d to 205l provided in the drive ring 205, and second drive pins 204m to 204u are cam grooves 206m of a cover member 206 described later. Engaging with ~ 206u. As the driving ring 205 rotates, each diaphragm blade 204 receives driving force through the driving ring 205 and rotates around the optical axis, and each second driving pin extends along the cam groove. 2 is formed.

  The cover member 206 has an opening 206a. Engagement holes 206e and 206f provided in the cover member 206 engage with engagement shafts 202e and 202f provided in the base member 202, respectively, and a screw 209b is connected to a screw hole 202g provided in the base member 202. The base member 202 is fixed at a predetermined position by fastening together via screw through holes 206 g provided in the cover member 206. The screw 209a is similarly fixed to the base member 202.

  The drive unit 208 (drive source) uses, for example, a stepping motor, a galvano motor, or the like. A pinion 207 a is attached to the rotation shaft 208 a of the drive unit 208. The drive unit 208 is attached to the cover member 206 and fixed by screws.

  The pinion 207a and the intermediate gear 207b have a gear shape formed of resin or metal, and can transmit power. An intermediate gear 207b is engaged with the pinion 207a. The intermediate gear 207b is pivotally supported by a rotating shaft 202h provided on the base member 202, and a driving force from the drive unit 208 is transmitted to the intermediate gear 207b via the pinion 207a. The

  A frame member 201, which is an example of an opening forming member, is fixed to an optical device such as in a lens barrel. The frame member 201 is provided with a fixed opening 201 a so as to cover the diaphragm device 200. Here, the diaphragm device 200 means a device for driving the diaphragm blades 204 including the base member 202, the drive ring 205, the diaphragm blades 204, the cover member 206, the drive unit 208, and the like.

  The frame member 201 is provided with guide grooves 201h and 201i, which are respectively engaged with guide pins 206h and 206i provided on the cover member 206, so that the diaphragm device 200 can move substantially linearly with respect to the frame member 201. It has become. Further, the frame member 201 is provided with a gear portion 201b that is a rack having a linear tooth stripe and meshes with the intermediate gear 207b described above. The driving force generated from the drive unit 208 is transmitted to the gear unit 201b of the frame member 201 via the intermediate gear 207b that meshes with the pinion 207a at the second meshing position. Since the frame member 201 is fixed in the lens barrel, the diaphragm device 200 moves linearly with respect to the frame member 201 by the drive of the drive unit 208. The frame member 201 is provided with hooks 201j, 201k, and 201l for fixing in the lens barrel, and movement in the lens barrel is restricted. At this time, the center of the diaphragm opening 204 a formed by the diaphragm blades 204 of the diaphragm device 200 moves away from the center of the frame member 201. Further, the diaphragm device 200 may be driven by directly engaging the pinion 207a and the gear portion 201b of the frame member 201 without using an intermediate gear. The frame member 201 here may be integrated with an optical device or a component in the optical device.

  FIG. 3 shows the process of changing from the full aperture to the small aperture as viewed from the base member 202 side in the order of (A) → (B) → (C), and from the full aperture to the small aperture as viewed from the frame member 201 side. This process is shown in the order of (D) → (E) → (F). 3A and 3D are in an open state, and the light passage opening 200 a is a fixed opening 202 a of the base member 202. 3B and 3E show an intermediate stop state, and the light passage opening 200a becomes the stop opening 204a created by the stop blade 204. FIG. 3C and 3F show a small stop state, and the light passage opening 200a becomes the stop opening 204a created by the stop blade 204. FIG. From the open state (A) to the small stop state (C), the center of the stop opening 204a moves linearly. The light passage opening 200a in the open state may be formed by the diaphragm opening 204a created by the diaphragm blades 204. That is, when the aperture opening 204a is the light passage aperture 200a in the open state, the center of the aperture opening 204a and the center of the fixed aperture 202a are at the same position, and the annular engagement portion 205a of the drive ring 205 is located. The center is also at the same position as the center of the fixed opening 202a. In the process of squeezing the aperture blade 204 from that position, the aperture ring 204a formed by the aperture blade 204 moves as the drive ring 205 moves parallel to the aperture, that is, moves the drive ring 205. The center of the aperture opening 204a moves away from the center of the fixed opening 202a.

  4 (A), 4 (B), and 4 (C) show the process of removing the base member 202 when viewed from the base member 202 side and changing from the full aperture to the small aperture as shown in (A) → (B) → (C). 4D, 4E, and 4F, a process in which the base member 202 is removed and one of the diaphragm blades 204 changes from open to small is shown in (D) → (E) → ( F).

  Thus, the pinion gear 207a that transmits the driving force for driving the drive ring 205 meshes with the gear portion 201b provided on the frame member 201 and moves relative to the frame member 201, whereby the entire diaphragm device 200 is moved. It moves relative to the frame member 201. In other words, the drive ring 205 and the diaphragm blade 204 included in the diaphragm device 200 move in parallel with the opening surface of the fixed opening 201a.

  FIG. 5 shows light that causes ghost in the first lens group 1 in the optical apparatus in which the blade driving device according to the present embodiment is arranged. For example, sunlight is reflected by the inner surface of the lens barrel or the like. 5 is directed toward the image sensor 107 along the locus of the arrow in FIG. Such reflection on the inner surface of the lens barrel causes ghost. However, in the optical apparatus according to this embodiment, the lower side of the optical path where harmful light is concentrated can be blocked by the diaphragm blade 204. Can be reduced.

  FIG. 6 shows light that causes a ghost in the first lens group 1. For example, sunlight rays are totally reflected on the lens surface and travel toward the image sensor 107 along the locus shown. Such multiple reflections have caused ghosts. However, in the optical apparatus of this embodiment, only the lower side of the optical path where harmful light is concentrated can be blocked by the diaphragm blades 204, thereby preventing ghosts. It is possible.

  At this time, since it is not necessary to shield the upper side of the optical path, it is possible to prevent the occurrence of a ghost with the minimum necessary light shielding. Furthermore, in the first embodiment, in a shooting environment with strong light (when the aperture opening 204a is made small), the state can be controlled to the states shown in FIGS. 3B, 3C, 3E, and 3F. Since it is a possible structure, it can be used in an ordinary shooting environment without affecting the effective area of the lens when the aperture is open.

  FIG. 7 is a cross-sectional view of the taking lens when the diaphragm device is in the state of FIG. The light shown in FIG. 7 indicates light reflected from the surface of the image sensor 107. Unlike the lens, it is difficult to apply an anti-reflection coating on the imaging element surface. Reflection of light on the image pickup element surface is a factor of multiple reflection in the photographing lens, and is a factor of generating ghost. In the optical apparatus of the present embodiment, as shown in FIG. 7, when the aperture opening 204a is small, the aperture aperture 204a is formed only in one direction with respect to the center O of the lens. The light incident on the aperture opening 204a is reflected by the imaging element surface, and the reflected light returns to the opposite side with respect to the lens center O. At this time, since the reflected light reaches the light shielding portion of the diaphragm blade 204, the reflected light is blocked. In an optical apparatus in which the center of the lens and the center of the aperture opening are substantially the same axis, the reflected light cannot be blocked by the aperture blade because of its symmetry. In the optical apparatus of the present embodiment, multiple reflections (particularly, reflection of light reaching the imaging element surface) within the lens can be prevented, and ghosting can be prevented.

  As described above, the optical apparatus of the present embodiment can prevent ghosts that occur in an environment with strong light. As described in the above embodiment, the lower side of the aperture opening 204a is shielded from light, so that it is possible to effectively generate a ghost for light that is particularly easily incident on an optical device from the upper side such as sunlight or illumination light. It is possible to prevent such a problem and exerts a great effect in fields such as surveillance cameras and vehicle-mounted cameras used outdoors. When the direction of light incident on the optical apparatus according to the present embodiment is a specific direction other than upward, the center of the aperture opening 204a moves to the side on which light enters in the aperture opening 204a. By configuring or arranging the aperture device 200 as described above, it is possible to effectively reduce the occurrence of ghosts.

<Embodiment 2>
8 and 9 are exploded perspective views of the blade driving device according to the second embodiment of the present invention.

  As in the first embodiment, the diaphragm device 200 according to the second embodiment includes a base member 202, a drive ring 205, a diaphragm blade 204, a cover member 206, a pinion 207a, an intermediate gear 207b, and a drive unit 208. The function of forming the diaphragm opening 204a in which the diaphragm blade 204 becomes the light passage opening 200a by the driving of the driving unit 208 is the same as that of the first embodiment.

  The frame member 201 is a frame member 201 provided with a fixed opening 201a. The frame member 201 is provided with a rotation support hole 201 x and is engaged with a rotation support pin 206 x (rotation shaft) provided in the cover member 206. As shown in FIG. 10A described later, the frame member 201 is provided with a gear portion 201w (movement mechanism) of an internal gear having an appropriate R-arc pitch centering on a rotation support hole 201x. The gear part 201w meshes with an intermediate gear 207b configured in the diaphragm device 200. The rotation support pins 206x and the gear portion 201w are provided at positions where the drive ring 205 can rotate with respect to the frame member 201.

  The driving force generated from the drive unit 208 is transmitted to the gear unit 201w of the frame member 201 via the pinion 207a and the intermediate gear 207b. The aperture device 200 rotates around the rotation support hole 201x of the frame member 201 fixed to the lens barrel or the like, and the center of the aperture opening 204a formed by the aperture blade 204 is relative to the center of the fixed opening 201a of the frame member 201. Moving.

  FIG. 10 shows the process of changing from the full aperture to the small aperture as seen from the base member 202 side in the order of FIGS. 10A to 10C, and from the full aperture to the small aperture as seen from the frame member 201 side. The process of changing to is shown in the order of FIG. 10 (D) → (E) → (F). 10A and 10D show an open state, and the light passage opening 200 a is a fixed opening 202 a of the base member 202. 10B and 10E show the intermediate stop state, and the light passage opening 200a becomes the stop opening 204a created by the stop blade 204. FIG. 10C and 10F show a small stop state, and the light passage opening 200a becomes the stop opening 204a created by the stop blade 204. FIG. From the open state (A) to the small stop state (C), the stop opening 204 a rotates around the rotation support pin 206 x of the cover member 206. The light passage opening 200a in the open state may be formed by the diaphragm opening 204a created by the diaphragm blades 204.

<Embodiment 3>
FIG. 11 shows a blade driving device according to the third embodiment of the present invention. In the diaphragm device 200 according to the first embodiment, the driving force of the driving unit 208 is transmitted to the frame member 201 via the intermediate gear 207b. A blade drive device is shown in which the movement of the diaphragm device 200 is made independent of the driving force generated by the drive unit 208, rather than the diaphragm device 200 being moved.

  In other words, the cover member 206 is provided with a lever 206w that extends to the outside of the frame member 201. The lever 206w can be manually operated by the user, for example, and as shown in FIGS. 11A, 11B, and 11C, the lever 206w is moved with respect to an arbitrary aperture opening 204a. The position of the aperture opening 204 a is moved with respect to the center of the member 201.

  FIGS. 11D, 11E, and 11F are rear views of FIGS. 11A, 11B, and 11C. As in the first embodiment, guide pins 206h and 206i of the cover member 206 are illustrated. Are engaged with the guide grooves 201h and 201i of the frame member 201, respectively, and linear movement is possible.

  The lever 206w as the moving means is not limited to manual operation, and a drive unit such as a motor or a galvanometer may be provided to perform control independent of the drive unit 208 of the diaphragm device 200. In this case, for example, on the display screen of the optical device equipped with the blade driving device according to the present embodiment, the option of whether to enable the ghost reduction function is displayed, and the user selects to enable The lever 206w is moved so that the center of the aperture opening 204a moves, or a light amount detection means is provided at any position of the optical device or blade driving device, and the lever 206w is automatically detected when a light amount of a predetermined amount or more is detected. Or the like can be controlled.

  Further, as in the second embodiment, the diaphragm device 200 may be rotated with respect to the frame member 201. By adopting such a configuration, it is possible to appropriately select the movement of the center of the aperture opening 204a such that the aperture device 200 is not moved when no light enters from the upper side of the optical path.

<Embodiment 4>
In FIG. 12, the disassembled perspective view of the blade drive device which concerns on Embodiment 4 of this invention is shown.

  In the fourth embodiment, the diaphragm device 200 includes a base member 202, a drive ring 205, a diaphragm blade 204, a cover member 206, a pinion 207a, and a drive unit 208, as in the first embodiment. The function of forming the aperture opening 204a in which the aperture blade 204 becomes the light passage aperture 200a when the driving unit 208 is driven is the same as that of the first embodiment.

  The frame member 201 is a frame member 201 provided with a fixed opening 201a. The frame member 201 is provided with positioning holes 201y and 201z, which are respectively engaged with the positioning shafts 206y and 206z provided in the cover member 206, and the center of the fixed opening 201a of the frame member 201 and the aperture opening of the aperture device 200. Although 204a is on the same axis, it is fixed so as to be positioned on the upper side with respect to the optical axis center in the lens barrel to which the frame member 201 is fixed.

  FIG. 13 shows the process of changing from the full aperture to the small aperture as seen from the base member 202 side, in the order of FIGS. 13 (A) → (B) → (C). The changing process is shown in the order of FIG. 13 (D) → (E) → (F).

  13A and 13D are in an open state, and the light passage opening 200 a is a fixed opening 202 a of the base member 202. 13B and 13E show the intermediate stop state, and the light passage opening 200a becomes the stop opening 204a created by the stop blade 204. FIG. FIGS. 13C and 13F show a small stop state, and the light passage opening 200 a becomes the stop opening 204 a created by the stop blade 204.

  In the present embodiment, the diaphragm member 200 is fixed to the frame member 201 by fixing the frame member 201 and the cover member 206 so as not to change the relative positions, and the opening center and the optical axis center are at different positions. Therefore, the aperture of the aperture 204a changes from the open state (A) to the small aperture state (C) so that the lower side is always shielded from the center of the optical axis. At this time, the center of the aperture opening 204a is shifted in any one of the radial directions of the lens barrel with respect to the central axis of the lens barrel in which the blade driving device is disposed.

  That is, the center of the aperture opening 204a is on the upper side with respect to the optical axis center, and light always passes above the optical axis center. In the present embodiment, as described with reference to FIGS. 5, 6, and 7 shown in the first embodiment, an effect is exhibited against a ghost caused by the optical path from the upper side. For example, when sunlight always enters from the upper side of the lens in an environment where midnight sun continues, or when using a blade drive device in an environment where the sunlight is used only in a relatively high position, ghosting may occur. It is effective for reduction.

  The light passage opening 200a in the open state may be formed by the diaphragm opening 204a created by the diaphragm blades 204. Further, the cover member 206 may be fixed to the lens barrel without providing the frame member 201.

  In this embodiment, it is easy to freely change the attachment position of the diaphragm device 200 with respect to the frame member 201 by adjusting the positions where the positioning holes 201y and 201z are provided, that is, a mirror to which the blade driving device is attached. The position of the light passage opening 200a in the cylinder or the like can be easily adjusted with respect to the optical axis center. For example, by adjusting the positioning holes 201y and 201z provided in the frame member 201 when the blade driving device according to the present embodiment is used in an environment with little incident light itself or an environment with little light that causes ghosting. Further, it is possible to easily change so that the center axis of the light passage opening 200a formed by the aperture opening 204a is aligned with the center of the optical axis.

<Embodiment 5>
14 and 15 are exploded perspective views showing a blade driving device as an example of the blade driving device according to the fifth embodiment of the present invention.

  The diaphragm device 200 in the fifth embodiment has a configuration in which the cover member 206 and the frame member 201 in the first embodiment are integrated. Therefore, the diaphragm device 200 includes a base member 202, a drive ring 205, a diaphragm blade 204, a pinion 207a, an intermediate gear 207b, a drive unit 208, and a frame member 201. The function of forming the aperture opening 204a in which the aperture blade 204 becomes the light passage aperture 200a when the driving unit 208 is driven is the same as that of the first embodiment.

  The frame member 201 having the fixed opening 201a is provided with engagement long holes 201y and 201z, which are engaged with the engagement pins 202y and 202z provided on the base member 202, respectively. The frame member 201 is provided with a gear-shaped rack 201 b (moving mechanism) and meshes with an intermediate gear 207 b that is configured in the diaphragm device 200.

  The driving force generated from the drive unit 208 is transmitted to the pinion 207a connected to the drive unit 208, and is transmitted to the gear unit 201b of the frame member 201 through the intermediate gear 207b. The aperture device 200 moves in the longitudinal direction of the long support holes 201y and 201z of the frame member 201 fixed to a lens barrel or the like. Further, the frame member 201 at this time may be a part of the lens barrel part.

  The pinion gear 207a meshes with a driven portion 205m provided on the driving ring 205, and the driving force generated by the driving portion 208 is transmitted to the driving ring 205 via the pinion 207a to drive the driving ring 205. Do.

  The drive ring 205 is provided with an annular engagement portion 205a, and the drive ring 205 is engaged with an engagement portion 202b formed by a protrusion shape arranged annularly around the center of the optical axis of the base member 202. It is structured to be attached to the base member 202 so as to be able to rotate.

  Further, the drive ring 205 is provided with a plurality of cam groove portions 205p that are annularly arranged around the center of the optical axis and is engaged with the first engagement pins 204p of the diaphragm blades 204. The diaphragm blade 204 is provided with a second engagement pin 204q different from the first engagement pin 204p, and is engaged with an engagement hole 202q provided in the base member 202.

  Along with the rotation operation of the drive ring 205 described above, the diaphragm blades 204 rotate around the engaging pins 204q, and the plurality of diaphragm blades 204 form the diaphragm openings 204a. As the driving unit 208 is driven, the diaphragm device 200 can move in the longitudinal direction of the engagement long holes 201y and 201z of the frame member 201 with respect to the frame member 201, and therefore, the center of the diaphragm opening 204a formed by the diaphragm blades 204 Moves relative to the center of the fixed opening 201a of the frame member 201.

  FIG. 16 shows the process of changing from the full aperture to the small aperture as viewed from the aperture device 200 side in the order of FIGS. 16A to 16C. The process of changing to an aperture is shown in the order of FIG. 16D → (E) → (F).

  16A and 16D are in an open state, and the light passage opening 200 a is a fixed opening 202 a of the base member 202. FIGS. 16B and 16E show the intermediate stop state, and the light passage opening 200a becomes the stop opening 204a created by the stop blade 204. FIG. 16C and 16F show a small stop state, and the light passage opening 200a becomes the stop opening 204a created by the stop blades 204. FIG.

  From the open state (A) to the small stop state (C), the stop opening 204a moves in the longitudinal direction of the engagement long holes 201y and 201z of the frame member 201. The light passage opening 200a in the open state may be formed by the diaphragm opening 204a created by the diaphragm blades 204.

  In this embodiment, since the cover member 206 and the frame member 201 are integrated with each other as compared with the other embodiments, the number of components and the space in the optical axis direction can be reduced.

<Embodiment 6>
FIG. 17 shows a schematic configuration of a camera (imaging device) as an optical apparatus equipped with the blade driving device described in the first to fifth embodiments.

  In the lens barrel portion 21 of the video camera, an imaging optical system including the variable magnification lens 32, the blade driving device described in the first to fifth embodiments, and the focus lens 29 is accommodated.

  The imaging element 25 is configured by a photoelectric conversion element such as a CCD sensor or a CMOS sensor. The image sensor 25 photoelectrically converts a subject image formed by the photographing optical system and outputs an electrical signal. The brightness of the subject image formed on the image sensor 25 (that is, the amount of light reaching the image sensor 25) is appropriately set by changing the aperture of the aperture device 200 or moving the ND filter back and forth. Can do.

  The electrical signal output from the image sensor 25 is subjected to various image processing by the image processing circuit 26. Thereby, a video signal (video output) is generated.

  The controller 22 controls the zoom motor 31 in response to a zoom switch (not shown) being operated by the user, and moves the zoom lens 32 to perform zooming. The controller 22 detects the contrast of the video signal, controls the focus motor 28 according to the contrast, and moves the focus lens 29 to perform autofocus.

  Further, the controller 22 controls the drive unit 208 (and the ND drive unit) of the aperture stop device 200 based on the luminance information in the video signal to adjust the light amount. Thereby, blur and ghost at the time of shooting can be made into a natural shape, and a high-quality video can be recorded. In addition, since the aperture device 200 built in the lens barrel is small, the lens barrel and the entire camera can be miniaturized.

  In each of the above embodiments, the frame member 201 is described as an example of the opening forming member. However, the opening forming member that forms the fixed opening is not limited to this, and other members may be used. Even when the diameter of the fixed opening 201a provided in the frame member 201 is set to be relatively large and the fixed opening 201a that does not substantially form the light passage opening 200a is formed, the diaphragm blades 204 are formed in the fixed opening 201a. As long as it moves forward and backward, the effects of the present invention can be achieved. In that case, the light passage opening 200a may be the stop opening 204a formed by the stop blade 204 at all times.

  Each embodiment described above is only a representative example, and various modifications and changes can be made to each embodiment in carrying out the present invention.

200 Drawing device 201 Frame member (opening forming member)
201a fixed opening 202 base member 202a fixed opening 204 diaphragm blade 205 drive ring 206 cover member 207a pinion 207b intermediate gear 208 drive unit 209 screw

Claims (8)

An opening forming member that forms a fixed opening through which light passes;
A plurality of aperture blades that form an aperture opening by moving forward and backward with respect to the fixed aperture by a driving force from a drive source;
A drive ring that is disposed so as to surround the central axis of the fixed opening, and that transmits the driving force to the plurality of diaphragm blades by a rotation operation;
A moving mechanism for moving the drive ring in parallel with the opening surface of the fixed opening,
The blade driving device according to claim 1, wherein the aperture is moved in parallel with the opening surface by moving the drive ring by the moving mechanism. The moving mechanism moves the driving ring in parallel with the opening surface of the fixed opening by a driving force generated by the driving source,
2. The blade driving device according to claim 1, wherein the center of the aperture opening moves away from the center of the fixed opening as the driving source exerts a driving force to rotate the driving ring. A drive gear for transmitting a drive force from the drive source to the drive ring;
3. The blade driving device according to claim 1, wherein the moving mechanism is a gear tooth that is provided on the opening forming member and transmits a driving force from the driving gear. 4.   4. The blade driving device according to claim 3, wherein the gear teeth are provided in a straight line, and the diaphragm opening moves linearly with respect to a center of the fixed opening. The drive ring has a rotation shaft provided so as to be rotatable with respect to the opening forming member;
4. The blade drive according to claim 3, wherein the gear tooth is provided along an arbitrary circle having the rotation axis as a center, and the diaphragm opening rotates with respect to a center of the fixed opening. apparatus.   A second meshing position for transmitting a driving force to the gear teeth is provided on the opposite side of the first meshing position where the drive gear meshes with the drive ring with respect to the drive gear. Item 6. The blade driving device according to any one of Items 3 to 5.   An optical apparatus comprising the blade driving device according to any one of claims 1 to 6. An opening forming member that forms a fixed opening through which light passes;
A plurality of aperture blades that form an aperture opening by moving forward and backward with respect to the fixed aperture by a driving force from a drive source;
A blade driving device that is disposed so as to surround the fixed opening and has a drive ring that transmits the driving force to the plurality of diaphragm blades by a rotation operation;
A lens barrel that houses the blade driving device so that the light can pass through,
An optical apparatus, wherein the drive ring is attached to the opening forming member so that the center of the aperture opening is located in any radial direction with respect to the central axis of the lens barrel.

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