JP6918502B2 - Blade drive - Google Patents

Description

The present invention relates to a blade drive device mounted on an optical device such as an image pickup device or an interchangeable lens.

In recent years, an image pickup device that converts an optical image into an electric signal and records the electric signal by digitizing it using an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-oxide Sensor) sensor has become widespread. .. Such an imaging device is generally called a digital camera. A conventional digital camera is equipped with an aperture device for adjusting the amount of light received by the image sensor. This diaphragm device includes a base member, a plurality of diaphragm blades, a rotating ring, and a drive motor for driving the plurality of diaphragm blades. The plurality of diaphragm blades are supported by the base member so as to be openable and closable, and form an opening through which light passes. The rotating ring connects a plurality of diaphragm blades. The area of the opening can be changed by driving a plurality of diaphragm blades by a drive motor via a rotating ring.

Japanese Unexamined Patent Publication No. 2010-14814

In a digital camera whose main function is still image shooting, for example, a stepping motor or a DC motor can be considered as a drive motor of the diaphragm device. A drive gear is fixed to the rotating shaft of the stepping motor, and this drive gear meshes with the gear portion of the rotating ring. When the rotary ring is rotationally driven by the drive motor, the diaphragm blades rotate in the opening and closing directions.

However, in this type of diaphragm device, there is a gap called backlash in the portion where the drive gear and the gear portion mesh with each other. Therefore, the teeth of the drive gear collide with the teeth of the gear portion, and noise is generated when the diaphragm device is driven. If noise is generated during movie shooting, it causes noise when recording sound with a microphone built in the camera, which is not preferable. Therefore, in a digital camera capable of shooting a moving image, an aperture device in which an elastic member is attached to a rotating ring is adopted (Patent Document 1).

However, since the elastic member is attached to the rotating ring, it is difficult to reduce the size of the rotating ring, and the size of the entire drawing device tends to increase accordingly.

On the other hand, the present invention provides a diaphragm device (blade drive device) that can be used for moving image shooting and can be easily miniaturized.

The blade drive device as one aspect of the present invention is
An opening forming member that forms an opening through which light passes,
A group of diaphragm blades in which a diaphragm opening is woven into the opening,
The rotating member that drives the diaphragm blade group and
A space forming member that forms a drive space for the rotating member with the opening forming member is provided.
The diaphragm blade group arranged between the opening forming member and the rotating member rotates by receiving a driving force from the rotating member, so that the blade tip side of the diaphragm blade group is knitted into the opening. At the same time, the blade surface on the opening forming member side slides into contact with the peripheral edge of the opening, and the convex protrusions provided on either one of the diaphragm blade group and the rotating member abuts on the other. The rotating member is urged toward the space forming member side ,
The driving force is transmitted by inserting a drive pin provided on one of the diaphragm blade group and the rotating member into a hole provided on the other of the diaphragm blade group and the rotating member.
The convex protrusion is provided at a position radially overlapping with the drive pin on the outer side of the opening in the radial direction .

Blade drive equipment according to the present invention, it is possible to adaptable and miniaturized video imaging.

An exploded perspective view of the blade driving device according to the first embodiment. A front view (without a cover member) showing a change in the aperture opening of the blade drive device according to the first embodiment. The perspective view of the blade drive device which concerns on Embodiment 1. FIG. FIG. 3 is a perspective view (without a cover member) of the blade driving device according to the first embodiment. FIG. 3 is a cross-sectional view of the blade driving device according to the first embodiment. FIG. 3 is a cross-sectional view (enlarged) of the blade driving device according to the first embodiment. A detailed view of the rotating member according to the first embodiment. A detailed portion of the rotating member according to the second embodiment. The perspective view of the blade drive device which concerns on Embodiment 3. FIG. 3 is a cross-sectional view of the blade driving device according to the third embodiment. An exploded perspective view of the blade drive device according to the third embodiment.

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

<Embodiment 1>
FIG. 1 shows an exploded perspective view of a diaphragm device as a blade driving device, which is an example of the blade driving device according to the first embodiment of the present invention. In FIG. 1, the optical axis center 100 of the blade driving device is shown. A drive unit 101, which is a drive source for driving the blade drive device, is attached to a base member 102 as an opening forming member having an opening 102a formed in the center. The base member 102 is formed by resin molding, for example, in the present embodiment, and has a plurality of engaging pins 102c. Examples of the drive unit 101 include a stepping motor and a galvanometer. A pinion 103 is attached to the rotating shaft of the drive unit 101.

A rotating member 104 (drive ring) for driving the diaphragm blade 105 is provided on the base member 102. For example, in the present embodiment, it is a circular sheet-shaped member formed by resin molding. A circular opening that serves as a light passage path through which light passes is formed in the central portion thereof.

The rotating member 104 is provided with a plurality of erected drive pins 104d, a driven portion 104e provided at the outer peripheral end portion to which the intermediate gear 108 is connected, and a partially protruding portion at the outer peripheral end portion. It has a light-shielding portion 104f.

Here, the rotating member 104 is created by, for example, pressing a resin film (PET sheet material or the like). When the rotating member 104 is made of a resin film, the rotating member 104 can be made thin and light. Further, when the rotating member 104 is made of a resin film, the portion for guiding the operation of the rotating member 104 does not require strength as compared with the case where the rotating member is made of resin molding. For example, it is possible to guide the rotating member 104 with a thin guide pin that guides the diaphragm blades. When press working is possible, the shape accuracy can be formed with higher accuracy than the shape accuracy of resin molding, so that the drawing accuracy can be improved. Of course, the rotating member 104 does not have to be formed of a thin sheet-shaped member, and may be formed by resin molding.

Further, the rotating member 104 has a gear portion which is a driven portion 104e. The driven portion 104e meshes with the pinion 103. The rotational force generated by the drive unit 101 is transmitted from the pinion 103 to the driven unit 104e via the intermediate gear 108, whereby the rotating member 104 rotates. For example, in the present embodiment, the rotational force of the drive unit 101 is transmitted from the pinion 103 to the intermediate gear 108 and the rotating member 104, but a drive lever may be used instead of the pinion 103. When a drive lever is used, a cam groove, a driven pin, or the like may be used as the driven portion of the rotating member 104. Further, 104f is a light-shielding portion. The light-shielding portion 104f moves in and out of the slit of the photo interrupter 107 to act as a sensor for detecting the rotational position of the rotating member 104. It is used to detect the initial position of the blade drive device.

In the present embodiment, a plurality of (7) diaphragm blades 105 are arranged in a ring shape so as to surround the opening through which light passes. Each throttle blade 105 is formed with an engaging hole 105d and a cam groove 105c, which are driven portions. Such a diaphragm blade 105 may be produced, for example, by pressing a PET sheet material or the like, or by resin molding or the like. Further, the number of diaphragm blades may be any number as long as it is 3 or more, and in the present embodiment, it is composed of 7 diaphragm blades in order to increase the circularity of the diaphragm opening. In this embodiment, a plurality of diaphragm blades 105 form a blade group. In particular, a plurality of diaphragm blades 105 are woven so as to be sandwiched between adjacent diaphragm blades 105.

The cover member 106 as the other opening forming member accommodates the plurality of diaphragm blades 105 described above and the rotating member 104 for driving the blades between the base member 102 and the rotating member 104. It forms a vane chamber in which the vanes travel. That is, a plurality of diaphragm blades 105 travel (drive) in the blade chamber (drive space) formed by the base member 102 and the cover member 106 as the rotating member 104 rotates. The cover member 106 is formed with an opening 106a that communicates with the opening of the base member 102, and is an opening forming member like the base member 102. The cover member 106 is produced by resin molding or press working of a PET sheet material or the like.

The engagement hole 105d of the diaphragm blade 105 engages with the drive pin 104d of the rotating member 104. When the pinion 103 rotates, a force is applied to the driven portion 104e of the rotating member 104 via the intermediate gear 108, and the rotating member 104 rotates. Then, a driving force is applied from the driving pin 104d of the rotating member 104 to the engaging hole 105d of the diaphragm blade 105, and the diaphragm blade 105 is driven. At this time, the cam groove 105c of the diaphragm blade 105 is engaged with the engaging portion 102c of the base member 102. Therefore, the diaphragm blade 105 moves in and out of the opening 102a of the base member 102 by the cam groove 105c. As a result, the plurality of diaphragm blades 105 can adjust the diaphragm shape (diameter of the diaphragm opening) in the opening 102a of the base member 102, and the amount of light passing through can be adjusted. FIG. 2 shows a front view of the state in which the cover member 106 shown in FIG. 1 is removed. FIG. 2A shows the state of the maximum aperture (maximum aperture), FIG. 2B shows the state of the intermediate diaphragm, and FIG. 2C shows the state of the small diaphragm.

In the present embodiment, the diaphragm blade 105 in which seven blades are knitted to form a diaphragm opening will be described as an example, but other shutter blades, blades having an optical filter, and other blades to which various applications are applied will be described. It may be a drive device. The maximum opening of the portion through which light passes may be defined by the opening 106a of the base member 102 or the cover member 106, or may be defined by the ends of a plurality of diaphragm blades 105. In the present embodiment, the maximum opening is defined by the opening 106a of the cover member 106.

FIG. 3 is a perspective view of the first embodiment. FIG. 4 shows a state in which the cover member 106 is removed from FIG. Further, FIG. 5 is a cross-sectional view of the first embodiment, and FIG. 6 is an enlarged view of a cross-sectional view of the first embodiment.

As shown in FIGS. 3 and 4, the plurality of diaphragm blades 105 are arranged in an annular shape so that the front and back surfaces of the adjacent diaphragm blades overlap each other, and the tip end side of the diaphragm blades is knitted in one direction. In the first embodiment, the knitting direction of the tip of the diaphragm blade is the direction opposite to that of the rotating member 104 (direction A in FIGS. 5 and 6). Since the diaphragm blade 105 is made of an elastic material, when the tip of the diaphragm blade is knitted in the A direction, the diaphragm blade 105 exerts a force (reaction force) to return to the original flat shape. However, as shown in FIG. 6, since the opening 106a of the cover member 106 is in sliding contact with the diaphragm blade 105, a force is applied in the B direction on the engagement hole 105d side opposite to the tip end side of the diaphragm blade. Occurs.

FIG. 7 is a detailed view of the rotating member 104. The rotating member 104 has a receiving portion 104g around the drive pin 104d. Here, as shown in FIG. 6, when the rotating member 104 is incorporated into the base member 102, the receiving portion 104g of the rotating member 104 is closer to the diaphragm blade 105 than the bottom surface 102d forming the blade chamber of the base member 102. It is desirable that the protrusions are convex. Since the receiving portion 104g is convex, it is possible to directly apply the reaction force due to the knitting of the diaphragm blade 105 to the rotating member 104. The diaphragm blade 105 can press the rotating member 104 in the vicinity of the engaging hole 105d. Here, the receiving portion 104g preferably has a semicircular rail shape or a hemispherical shape in order to reduce friction due to pressing when the rotating member 104 rotates.

Further, as shown in FIG. 6, since the rotating member 104 is urged by the diaphragm blade 105, it is pressed against the base member 102. In the first embodiment, the rotating member 104 and the base member 102 come into contact with each other at a plurality of receiving portions 102e of the base member 102. The receiving portion 102e preferably has a semicircular rail shape or a hemispherical shape in order to reduce friction due to pressing when the rotating member 104 rotates. Further, in the first embodiment, the receiving portion 102e is provided on the base member 102, but the rotating member 104 may be provided with a convex shape toward the base member 102 side, and the base member 102 side may be flat.

Here, the effect of pressing the rotating member 104 toward the base member 102 and urging it will be described. In FIG. 6, the rotating member 104 and the diaphragm blade 105 rotate in the drive space h formed by the base member 102 and the cover member 106. When the rotating member 104 can move to the base member 102 side or the cover member 106 side in the drive space h, the intermediate gear 108 and the driven portion 104e of the rotating member 104 When the gears mesh with each other, the rotating member 104 rotates while vibrating in the drive space h due to the accuracy of the gears and the inclination of the gears. As a result, the phenomenon that the rotating member 104 separates from or comes into contact with the base member 102 or the cover member 106 may cause noise.

In the first embodiment, since the rotating member 104 is urged to the base member 102 side, the rotating member 104 may move to the base member 102 side or to the cover member 106 side in the drive space h. Can be prevented. That is, the cause of noise can be eliminated. In the first embodiment, the rotating member 104 can be urged by the diaphragm blade 105. It is possible to reduce noise at low cost without adding parts. In addition, since it is not necessary to add parts, it is possible to reduce noise while maintaining a small unit size.

Further, the blade driving device of the first embodiment is also effective for stable driving. In the conventional blade driving device, when the diaphragm blades are driven to a predetermined diaphragm area at high speed, the rotating member 104 stops and it takes a certain time for the diaphragm area to stabilize. In the blade driving device of the first embodiment, since the rotating member 104 is urged by the diaphragm blade 105, it is possible to suppress the vibration of the rotating member that occurs when the rotating member 104 is driven at high speed.

Since the rotating member stops without vibrating after high-speed driving, it is possible to stably form a predetermined throttle opening area. In the conventional blade driving device, the vibration of the rotating member has subsided, and the aperture opening area is not stable until it stops. However, in the photographing device equipped with the blade driving device of the first embodiment, the rotating member 104 is not vibrated. Since it can be stopped at, it is possible to shorten the time from driving the blade drive device to taking a picture.

Further, the blade driving device of the first embodiment is also effective in changing the performance of the blade driving device due to the difference in posture. In the conventional blade drive device, the positions of the rotating member 104 and the diaphragm blade 105 change in the drive space h when the base member 102 side is turned down and when the base member 102 side is turned up. Therefore, there is a problem that the area of the diaphragm opening formed by the plurality of diaphragm blades changes due to the posture difference, or abnormal noise is generated when the posture is changed. In the blade drive device of the first embodiment, since the rotating member 104 is urged, the positions of the rotating member 104 and the diaphragm blade 105 do not change even if the posture is changed, so that the area of the diaphragm opening does not change. .. Further, since the rotating member 104 and the diaphragm blade 105 do not move when the posture is changed, it is possible to prevent the generation of abnormal noise.

In the present embodiment, the maximum opening is formed by the opening 106a of the cover member 106, but this is not always the case, and as described in the first embodiment, the maximum opening is the opening of the base member 102. It may be formed by the portion 102a, or may be formed by the diaphragm blade 105.

Further, as shown in FIG. 6, the distance L from the receiving portion 104g to the end portion of the opening 106a is located in the center of the opening side of the drive pin 104d, receiving portion 10 4 g and the side in contact with the rotating member 104 Between the surface of the diaphragm blade and the inner surface of the cover member 106 including the opening 106a (height of the traveling space of the diaphragm blade 105) d and the knitting angle θ of the diaphragm blade 105, the diaphragm blade 105 is set from the maximum opening to the minimum. When the aperture is stopped down to the aperture, when Ltan θ> d, the aperture blade 105 comes into contact with the opening 106a, and the rotating member 104 can be pressed in the direction of arrow B. In the present embodiment, when the aperture blade 105 is stopped down to the minimum aperture, each dimension is set so that Ltan θ> 1.5d, so that the aperture opening other than the minimum aperture can be formed. The moving member 104 can be pressed.

<Embodiment 2>
Next, the blade driving device according to the second embodiment of the present invention will be described with reference to the drawings. Only the part different from the first embodiment will be described, and the other configurations are the same as those of the first embodiment.

As shown in FIG. 8, the receiving portion 104g of the rotating member 104 in the present embodiment may be provided not in the entire periphery of the drive pin 104d but in a part around the drive pin 104d. In particular, when the diaphragm blade 105 rotates to form a diaphragm opening, it is preferable that the diaphragm blade 105 is always provided with respect to a portion adjacent to one diaphragm blade 105, and FIG. 8 (a) shows that portion. It may be provided in the shape of a ridge shown in FIG. 8 or in the shape of a dot shown in FIG. 8 (b). Further, the receiving portion 104g does not have to be provided for all the driving pins 104d, and when the driving pins 104d provided with the receiving portion 104g are connected by a virtual line segment, the center O of the rotating member 104 is connected. It is preferable that they are arranged straddling. FIG. 8C shows a state in which the receiving portion 104g is provided for the three drive pins 104d. In this case, the center O of the rotating member 104 is included in the line segment connecting the three. included. That is, the drive pin 104d provided with the receiving portion 104g is provided so as to straddle the center O of the rotating member 104.

Further, the receiving portion 104g may be provided as the receiving portion 105g on the diaphragm blade 105 side, and in that case as well, at a position adjacent to the cam groove 105c (or engaging hole 105d) corresponding to the drive pin 104d. Therefore, when the diaphragm blade 105 rotates to narrow the diaphragm opening from the maximum aperture to the minimum diaphragm, it is preferable to always provide the diaphragm blade 105 at a position adjacent to the drive pin 104d. In particular, by being provided at a position closer to the opening center O than the cam groove 105c (or engaging hole 105d) and the drive pin 104d, the load received by the braided diaphragm blade 105 is farther from the opening center O. It becomes larger than the case where it is provided in the above, and the effect of pressing the rotating member 104 can be enhanced.

<Embodiment 3>
Next, the blade driving device according to the third embodiment of the present invention will be described with reference to the drawings. Only the part different from the first embodiment will be described, and the other configurations are the same as those of the first embodiment.

In the first embodiment, the receiving portion 104g is provided so as to abut around the engaging hole 105d of the diaphragm blade 105, but in the present embodiment, as shown in FIG. 9, the drive pin is provided instead of the engaging hole 105d. May be provided so as to engage with the cam groove or the engaging hole provided in the rotating member 104. FIG. 9A shows a perspective view of a state in which the tip end side of the diaphragm blade 105 is knitted when the diaphragm blade 105 is stopped down to the state of the minimum diaphragm in this form of the light amount adjusting device. FIG. 9B shows a state in which the cover member 106 is removed from FIG. 9A, and shows how the root side (drive pin side) of the braided diaphragm blade 105 holds down the rotating member 104. There is. FIG. 9C shows a state in which the diaphragm blade 105 is viewed from the side opposite to the knitted side, and shows a receiving portion 105 g provided near the drive pin. When the diaphragm blade 105 is knitted, the receiving portion 105g presses the rotating member 104, so that the rotating member 104 is suppressed from fluttering and vibrating.

In this case, the drive pin of the diaphragm blade 105 is brought into contact with the bottom surface of the diaphragm blade 105 without penetrating the cam groove or the engagement hole of the rotary member 104, and the drive pin causes the rotary member 104 in the diaphragm blade. The blade surface on the side may be configured so as not to be in sliding contact with the rotating member 104. According to this configuration, due to the rigidity of the drive pin, the operation is similar to that of the receiving portion 104g (or receiving portion 105g) of the first embodiment, that is, the rotating member 104 is urged toward the base member 102 and vibrates during rotation. Can be reduced.

FIG. 10 shows a cross-sectional view of the blade driving device according to the present embodiment and an enlarged view thereof. As shown in FIG. 10A, when the rotating member 104 rotates to form the minimum diaphragm, the tip end side of the diaphragm blade 105 rotates so as to be knitted by receiving a force in the direction of arrow A. At that time, as shown in FIG. 10B, the drive pin 104d side of the braided diaphragm blade 105 is in sliding contact with the end of the opening 106a as the diaphragm blade 105 rotates, and the load in the direction of arrow B is applied. Receive. When the receiving portion 105g presses the rotating member 104 in the arrow B direction, the rotating member 104 is reduced in vibration in the optical axis direction (arrow A or B direction).

The receiving portion 105g may be provided at a position where the diaphragm blade 105 always overlaps the rotating member 104 in the optical axis direction when the diaphragm blade 105 opens and closes the diaphragm opening from the maximum opening to the minimum diaphragm. It is a dot shape as shown in FIG. 9 (c).

At this time, the second receiving portion 102e provided on the base member 102 is in sliding contact with the rotating member 104 so as to abut on the surface of the rotating member 104 on the base member 102 side, so that the second receiving portion 102e is in sliding contact with the rotating member 104 in the optical axis direction. The sliding friction between the urged rotating member 104 and the base member 102 can be reduced, and the rotating member 104 can rotate without interfering with the operation of the rotating member 104.

FIG. 11 shows an exploded perspective view of the present embodiment. The rotating member 104 is pressed toward the base member 102 by receiving the urging force of the braided diaphragm blade 105 in the minimum throttle state shown in FIG. 11A. Regarding positioning in the radial direction orthogonal to the optical axis direction, the positioning portion 104i provided on the rotating member 104 is arranged so as to be in sliding contact with the inner diameter (inner wall) of the opening 102a of the base member 102. It can be decided. The positioning portion 104i has a convex portion extending in the radial direction in order to reduce sliding friction of the base member 102 with the opening 102a. A plurality of positioning portions 104i are provided at predetermined intervals along the circumferential direction of the rotating member 104, but they may be continuously and integrally formed in a rail shape.

FIG. 11B shows a surface opposite to that of FIG. 11A. In the present embodiment, nothing is provided on the engaging pin side of the surface of the diaphragm blade 105 on the braided side, but a second receiving portion may be provided at a position where it comes into contact with the base member 102. The second receiving portion may be provided on the corresponding base member 102 side.

As described above, the present invention adjusts, for example, the height of the convex protrusion, the contact area, etc., even if the shape of the rotating member, the drive space dimension of the rotating member, the material of the diaphragm blades, etc. are appropriately changed. As a result, the degree to which the weaving reaction force of the diaphragm blade group is transmitted to the rotating member is adjusted, the fluttering of the rotating member is suppressed, and the silent drive is realized.

In the embodiment described above, the base member 102 and the cover member 106 form a vane chamber (space). That is, one is an opening forming member and the other is a space forming member.

101 Aperture drive 102 Base member (base plate)
103 Pinion gear 104 Rotating member 105 Aperture blade 105g Receiving part (convex protrusion)
106 Cover member 107 Photo interrupter 108 Intermediate gear

Claims (4)

An opening forming member that forms an opening through which light passes,
A group of diaphragm blades in which a diaphragm opening is woven into the opening,
The rotating member that drives the diaphragm blade group and
A space forming member that forms a drive space for the rotating member with the opening forming member is provided.
The diaphragm blade group arranged between the opening forming member and the rotating member rotates by receiving a driving force from the rotating member, so that the blade tip side of the diaphragm blade group is knitted into the opening. At the same time, the blade surface on the opening forming member side slides into contact with the peripheral edge of the opening, and the convex protrusions provided on either one of the diaphragm blade group and the rotating member abuts on the other. The rotating member is urged toward the space forming member side ,
The driving force is transmitted by inserting a drive pin provided on one of the diaphragm blade group and the rotating member into a hole provided on the other of the diaphragm blade group and the rotating member.
The blade driving device is characterized in that the convex protrusion is provided at a position where the convex protrusion is radially outside the opening and overlaps with the drive pin. The blade driving device according to claim 1 , wherein the convex protrusion is provided at a position in the rotating member that always comes into contact with one of the diaphragm blades in the rotational operation of the diaphragm blade group. .. The blade driving device according to claim 1 or 2 , wherein the convex protrusion is provided on the entire periphery of the driving pin. An opening forming member that forms an opening through which light passes,
A group of diaphragm blades in which a diaphragm opening is woven into the opening,
The rotating member that drives the diaphragm blade group and
With the space forming member forming the drive space of the rotating member with the opening forming member
With
The diaphragm blade group arranged between the opening forming member and the rotating member rotates by receiving a driving force from the rotating member, so that the blade tip side of the diaphragm blade group is knitted into the opening. At the same time, the blade surface on the opening forming member side slides into contact with the peripheral edge of the opening, and the convex protrusions provided on either one of the diaphragm blade group and the rotating member abuts on the other. The rotating member is urged toward the space forming member side,
The convex protrusion is provided on the rotating member, and on the space forming member, on the center side of the opening rather than the inner diameter of the rotating member, than on the surface forming the blade chamber in which the diaphragm blade group is driven. , the blades drive you characterized in that protrudes to the opening forming member side.

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