JP2018120032A - Blade drive device and imaging device - Google Patents

Abstract

To provide a blade driving device and an imaging device that can support moving image shooting and can be easily reduced in size. An opening forming member that forms an opening through which light passes, a diaphragm blade group that forms a diaphragm opening in the opening by braiding, a rotating member that drives the diaphragm blade group, and the opening forming member A space forming member that forms a driving space for the rotating member between the aperture forming member and the rotating member, and the diaphragm blade group disposed between the opening forming member and the rotating member receives a driving force from the rotating member. The blade tip side of the diaphragm blade group is braided into the opening, and the blade surface on the opening forming member side is in sliding contact with the peripheral edge of the opening. A protruding protrusion provided on any one of the members abuts against the other and is biased. [Selection] Figure 7

Description

The present invention relates to a blade driving device mounted on an optical device such as an imaging device or an interchangeable lens.

  In recent years, imaging apparatuses that convert an optical image into an electrical signal and digitize and record the electrical signal using an imaging element such as a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) sensor have become widespread. . Such an imaging apparatus 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. The diaphragm device includes a base member, a plurality of diaphragm blades, a rotating ring, and a drive motor that drives 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 aperture area can be changed by driving a plurality of aperture blades with a drive motor via a rotating ring.

JP 2010-14814 A

  In a digital camera having still image shooting as a main function, for example, a stepping motor or a DC motor can be considered as a drive motor for an aperture device. A driving gear is fixed to the rotating shaft of the stepping motor, and this driving 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 direction and the closing direction.

  However, in this type of aperture device, there is a gap called backlash in the portion where the drive gear and the gear portion are engaged with each other. For this reason, 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 moving image shooting, for example, it may cause noise when recording sound with a microphone built in the camera, which is not preferable. Therefore, a digital camera capable of shooting a moving image employs a diaphragm device in which an elastic member is attached to a rotating ring (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 entire diaphragm device tends to increase in size accordingly.

  On the other hand, the present invention provides an aperture device and an imaging device that can support moving image shooting and can be easily reduced in size.

A blade driving device according to one aspect of the present invention,
An opening forming member that forms an opening through which light passes;
A diaphragm blade group that forms a diaphragm opening by weaving in the opening,
A rotating member for driving the diaphragm blade group;
A space forming member that forms a drive space of the rotating member with the opening forming member,
When the diaphragm blade group disposed between the opening forming member and the rotation member is rotated by receiving a driving force from the rotation member, 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 is in sliding contact with the peripheral edge portion of the opening, and the convex protrusion provided on one of the diaphragm blade group and the rotating member is in contact with the other and biased It is characterized by being.

  The blade driving device and the imaging device according to the present invention can cope with moving image shooting and can be miniaturized.

FIG. 3 is an exploded perspective view of the blade driving device according to the first embodiment. The front view which shows the change of the aperture opening of the blade | wing drive device which concerns on Embodiment 1 (without a cover member). 1 is a perspective view of a blade driving device according to Embodiment 1. FIG. FIG. 2 is a perspective view of the blade driving device according to the first embodiment (without a cover member). FIG. 3 is a cross-sectional view of the blade driving device according to the first embodiment. Sectional drawing (enlargement) of the blade drive device which concerns on Embodiment 1. FIG. FIG. 3 is a detailed view of a rotating member according to the first embodiment. The detail part of the rotation member which concerns on Embodiment 2. FIG. FIG. 6 is a perspective view of a blade driving device according to a third embodiment. Sectional drawing of the blade drive device which concerns on Embodiment 3. FIG. FIG. 6 is an exploded perspective view of a blade driving device according to a 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, an optical axis center 100 of the blade driving device is shown. A driving unit 101 serving as a driving source for driving the blade driving device is attached to a base member 102 as an opening forming member having an opening 102a formed in the center. In this embodiment, for example, the base member 102 is formed by resin molding and includes a plurality of engagement pins 102c. Examples of the drive unit 101 include a stepping motor and a galvanometer. A pinion 103 is attached to the rotation shaft of the drive unit 101.

  A rotating member 104 (driving ring) for driving the aperture blade 105 is provided on the base member 102. For example, in the present embodiment, a circular sheet-like member formed by resin molding, A circular opening serving as a light passage path through which light passes is formed at the center.

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

  Here, the rotating member 104 is formed 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 that guides the operation of the rotating member 104 does not require strength compared to the case where the rotating member is formed by resin molding. For example, the rotating member 104 can be guided by a thin guide pin that guides the diaphragm blades. When press working is possible, since the shape accuracy can be formed higher than the shape accuracy of resin molding, it is possible to increase the drawing accuracy. Of course, the rotating member 104 may not be formed by a thin sheet-like 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 in 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 this 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, the driven portion of the rotating member 104 may be a cam groove or a driven pin. Reference numeral 104f denotes a light shielding portion. When the light shielding portion 104f enters and exits the slit of the photo interrupter 107, it functions as a sensor that detects the rotation position of the rotation member 104. Used to detect the initial position of the blade drive device.

  In the present embodiment, a plurality (seven) of diaphragm blades 105 are annularly arranged so as to surround an opening through which light passes. Each aperture blade 105 is formed with an engagement hole 105d and a cam groove 105c, which are driven parts. Such a diaphragm blade 105 may be formed by, for example, pressing a PET sheet material or the like, or may be formed by resin molding or the like. Further, the number of diaphragm blades may be any number as long as it is three or more. In this embodiment, seven diaphragm blades are used to increase the circularity of the diaphragm aperture. In the present embodiment, a plurality of diaphragm blades 105 form a blade group. In particular, a plurality of aperture blades 105 are knitted so as to be sandwiched between adjacent aperture blades 105, respectively.

  The cover member 106 as the other opening forming member accommodates the plurality of diaphragm blades 105 and the rotation member 104 for driving these blades between the base member 102 and the rotation member 104. A blade chamber in which the blades travel is formed. That is, the 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 106 a 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 created by resin molding or pressing a PET sheet material.

  The engagement hole 105 d of the aperture blade 105 engages with the drive pin 104 d of the rotating member 104. When the pinion 103 rotates, a force is applied to the driven part 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 engagement hole 105d of the diaphragm blade 105, and the diaphragm blade 105 is driven. At this time, the cam groove 105 c of the diaphragm blade 105 is engaged with the engaging portion 102 c of the base member 102. Therefore, the aperture blade 105 enters and exits the opening 102a of the base member 102 through the cam groove 105c. As a result, the plurality of aperture blades 105 can adjust the aperture shape (diameter of aperture aperture) in the opening 102a of the base member 102 and adjust the amount of light passing through. FIG. 2 is a front view showing a state in which the cover member 106 shown in FIG. 1 is removed. FIG. 2 (a) shows a state in which the diaphragm is fully open (maximum opening), FIG. 2 (b) shows a state in which the diaphragm is in the middle state, and FIG.

  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 various other blades such as other shutter blades or blades having optical filters may be used. It is good also as a drive device. The maximum opening of the portion through which light passes may be defined by the opening 106 a of the base member 102 or the cover member 106, or may be defined by the ends of the plurality of aperture blades 105. In the present embodiment, the maximum opening is defined by the opening 106 a of the cover member 106.

  FIG. 3 is a perspective view of the first embodiment. FIG. 4 shows a state where the cover member 106 is removed from FIG. 5 is a cross-sectional view of the first embodiment, and FIG. 6 is an enlarged view of the 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 adjacent diaphragm blades overlap each other, and the leading end side of the diaphragm blades is knitted in one direction. In the first embodiment, the knitting direction at the tip of the diaphragm blade is the direction opposite to the rotating member 104 (direction A in FIGS. 5 and 6). Since the diaphragm blade 105 is made of an elastic material, when the leading edge of the diaphragm blade is knitted in the A direction, the diaphragm blade 105 has 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. Will occur.

  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 104 g of the rotating member 104 is closer to the diaphragm blade 105 side than the bottom surface 102 d forming the blade chamber of the base member 102. It is desirable to have a convex protrusion. Since the receiving portion 104g is convex, it is possible to directly apply the reaction force due to the knitting of the aperture blade 105 to the rotating member 104. The diaphragm blade 105 can press the rotating member 104 in the vicinity of the engagement hole 105d. Here, the receiving portion 104g preferably has a semicircular rail shape or a hemispherical shape in order to reduce friction caused by pressing when the rotating member 104 rotates.

  In addition, as shown in FIG. 6, the rotating member 104 is pressed by the base member 102 because it is urged by the diaphragm blade 105. In the first embodiment, the rotating member 104 and the base member 102 are in contact with each other at a plurality of receiving portions 102 e of the base member 102. The receiving portion 102e is preferably a semicircular rail shape or a hemispherical shape in order to reduce friction caused by pressing when the rotating member 104 rotates. In Embodiment 1, the receiving portion 102e is provided on the base member 102. However, the rotating member 104 may be provided with a convex shape toward the base member 102, and the base member 102 side may be flat.

  Here, the effect of pressing and urging the rotating member 104 toward the base member 102 will be described. In FIG. 6, the rotating member 104 and the diaphragm blade 105 rotate in a driving space h formed by the base member 102 and the cover member 106. If the rotating member 104 can move to the base member 102 side or the cover member 106 side in the driving space h, the intermediate gear 108 and the driven portion 104e of the rotating member 104 can be moved. When the gears mesh with each other, the rotating member 104 rotates while vibrating in the driving space h due to the accuracy of the gear and the inclination of the gear. As a result, the phenomenon that the rotating member 104 is separated 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 biased toward the base member 102, the rotating member 104 moves toward the base member 102 within the driving space h or moves toward the cover member 106. 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 the noise at low cost without adding any parts. In addition, since it is not necessary to add parts, it is possible to reduce the 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 blade is driven to a predetermined diaphragm area at a high speed, the rotation member 104 stops, and a certain time is required until the diaphragm area is stabilized. In the blade driving device of the first embodiment, since the rotation member 104 is urged by the diaphragm blade 105, vibration of the rotation member that occurs when driven at high speed can be suppressed.

  Since the rotating member stops without vibration after high-speed driving, a predetermined aperture opening area can be stably formed. In the conventional blade driving device, the vibration of the rotating member is settled, and the aperture area is not stable until it stops. However, in the photographing apparatus equipped with the blade driving device of Embodiment 1, the rotating member 104 is not vibrated. Therefore, it is possible to shorten the time from when the blade driving device is driven to when shooting is performed.

  Further, the blade driving device according to the first embodiment is also effective in changing the performance of the blade driving device due to a difference in posture. In the conventional blade driving device, the positions of the rotating member 104 and the diaphragm blade 105 are changed in the driving space h depending on whether the base member 102 side is down or up. For this reason, there is a problem that the area of the aperture opening formed by a plurality of aperture blades changes due to the attitude difference, or abnormal noise occurs when the attitude is changed. In the blade driving device of the first embodiment, since the rotation member 104 is biased, the positions of the rotation member 104 and the aperture blade 105 do not change even if the posture is changed, and thus the area of the aperture 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 necessarily 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 102 a or may be formed by the aperture blade 105.

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

<Embodiment 2>
Next, a blade driving device according to Embodiment 2 of the present invention will be described with reference to the drawings. Only parts 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 this embodiment may be provided not on the entire periphery of the drive pin 104d but on a part of the periphery of the drive pin 104d. In particular, when the aperture blade 105 rotates to form an aperture opening, it is preferably always provided for a portion adjacent to one aperture blade 105, and FIG. It is only necessary to be provided in a bowl shape as shown in FIG. Further, the receiving portion 104g does not have to be provided for all the driving pins 104d. When the driving pin 104d provided with the receiving portion 104g is connected by a virtual line segment, the center O of the rotating member 104 is set. It is preferable to be disposed across. 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 in the line segment connecting the three. included. That is, the drive pin 104 d provided with the receiving portion 104 g is provided across 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, similarly, at a position adjacent to the cam groove 105c (or the engagement hole 105d) corresponding to the drive pin 104d. Therefore, it is preferable that the diaphragm blade 105 is always provided at a position adjacent to the drive pin 104d when the diaphragm aperture is rotated from the maximum aperture to the minimum aperture. In particular, by being provided at a position closer to the opening center O than the cam groove 105c (or the engagement hole 105d) and the drive pin 104d, the load received by the knitting of the aperture blade 105 is far from the opening center O. It becomes larger than the case where it provides in, and the effect by the press with respect to the rotation member 104 can be improved.

<Embodiment 3>
Next, a blade driving device according to Embodiment 3 of the present invention will be described with reference to the drawings. Only parts 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 contact the periphery of the engagement hole 105d of the aperture blade 105. However, in the present embodiment, as shown in FIG. 9, a drive pin is used instead of the engagement hole 105d. It is good also as a structure engaged with the cam groove or engagement hole provided in the rotation member 104. FIG. 9A is a perspective view showing a state in which the leading end side of the diaphragm blade 105 is knitted when the diaphragm blade 105 is squeezed to the minimum diaphragm state in the light quantity adjusting device of this embodiment. FIG. 9B shows a state where the cover member 106 is removed from FIG. 9A, and shows a state in which the base side (drive pin side) of the knitted diaphragm blade 105 holds the rotating member 104. Yes. 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 105g provided near the drive pin. When the diaphragm blade 105 is knitted, the receiving portion 105g presses the rotating member 104, whereby the rotating member 104 is prevented from fluttering and vibrating.

  In this case, the cam pin or the engagement hole of the rotation member 104 is not penetrated, and the drive pin of the diaphragm blade 105 is in contact with the bottom surface thereof, and the rotation member 104 in the diaphragm blade is driven by the drive pin. The blade surface on the side may be configured not to be in sliding contact with the rotating member 104. According to this configuration, the rigidity of the drive pin causes the same operation as that of the receiving portion 104g (or the receiving portion 105g) of the first embodiment, that is, the rotating member 104 is urged toward the base member 102 to vibrate during rotation. Can be reduced.

  FIG. 10 shows a cross-sectional view and an enlarged view of the blade driving device according to the present embodiment. As shown in FIG. 10 (a), when the rotating member 104 rotates to form the minimum diaphragm, the leading end side of the diaphragm blade 105 rotates so as to be knitted by receiving the force in the direction of arrow A. At this time, as shown in FIG. 10B, the drive pin 104d side of the knitted 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 arrow B direction is reached. 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 only needs to be provided at a position that always overlaps the rotation member 104 in the optical axis direction when the aperture blade 105 opens and closes the aperture opening from the maximum aperture to the minimum aperture. The dot shape is as shown in FIG.

  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 come into contact with the surface of the rotating member 104 on the base member 102 side. The sliding friction between the biased rotation member 104 and the base member 102 can be reduced, and the rotation can be performed without hindering the operation of the rotation member 104.

  FIG. 11 shows an exploded perspective view of the present embodiment. In the minimum throttle state shown in FIG. 11A, the rotating member 104 receives a biasing force from the knitted diaphragm blade 105 and is pressed to the base member 102 side. With respect to 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 is decided. The positioning portion 104i has a convex portion extending in the radial direction in order to reduce sliding friction with the opening portion 102a of the base member 102. A plurality of positioning portions 104i are provided at a predetermined interval along the circumferential direction of the rotating member 104, but may be formed continuously in a rail shape.

  FIG. 11B shows a surface on the opposite side to FIG. In the present embodiment, nothing is provided on the engagement pin side on the surface of the diaphragm blade 105 on the knitting 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 and contact area of the convex protrusion even if the shape of the rotating member, the drive space size of the rotating member, the material of the diaphragm blades, etc. are appropriately changed. Thus, the degree of transmitting the weaving reaction force of the aperture blade group to the rotating member is adjusted, and the fluttering of the rotating member is suppressed to realize silent driving.

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

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

Claims (5)

An opening forming member that forms an opening through which light passes;
A diaphragm blade group that forms a diaphragm opening by weaving in the opening,
A rotating member for driving the diaphragm blade group;
A space forming member that forms a drive space of the rotating member with the opening forming member,
When the diaphragm blade group disposed between the opening forming member and the rotation member is rotated by receiving a driving force from the rotation member, 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 is in sliding contact with the peripheral edge portion of the opening, and the convex protrusion provided on one of the diaphragm blade group and the rotating member is in contact with the other and biased The blade drive device characterized by being made.   2. The blade driving device according to claim 1, wherein the convex protrusion is provided in the vicinity of an engaging portion between the plurality of diaphragm blades and the rotating member in the rotating member.   3. The blade driving device according to claim 2, wherein the convex protrusion is provided at a position always in contact with one of the diaphragm blades in the rotation operation of the diaphragm blade group.   4. The blade driving device according to claim 2, wherein the convex protrusion is provided closer to the center of the opening than the engaging portion. 5. An optical apparatus comprising the blade driving device according to any one of claims 1 to 4.

Images