JP2010078956A - Diaphragm device and lens barrel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diaphragm device and a lens barrel, for reducing an operating noise of aperture blades. <P>SOLUTION: The diaphragm device 4 includes: a plurality of aperture blades 30 disposed overlapping one another in a prescribed direction so as to define an aperture for transmitting incident object light; driving means 20 and 40 for openably/closably driving the plurality of aperture blades 30 so that the aperture may have a desired aperture size in accordance with the desired diaphragm value; and a separating means 50 for separating the adjacent aperture blades 30 from each other upon openably/closably driving the aperture blades 30 by the driving means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an aperture device and a lens barrel including the aperture device.

An aperture device is used in an optical apparatus such as a camera. This diaphragm device opens and closes a plurality of diaphragm blades around the optical axis to form an aperture (passage area) for incident subject light, and controls the aperture size to adjust the amount of subject light. (For example, refer to Patent Document 1).
JP 2006-337947 A

  In a lens barrel equipped with a conventional diaphragm device, operating noise is generated due to friction between diaphragm blades during driving. When a digital camera equipped with such a lens barrel is photographed in the moving image photographing mode, an operation sound due to friction between the diaphragm blades may be recorded as noise. Therefore, in the conventional diaphragm device, it has been desired to reduce the operation noise of the diaphragm blades.

  An object of the present invention is to provide a diaphragm device and a lens barrel that can reduce operating noise of diaphragm blades.

The present invention solves the above problems by the following means. In addition, in order to make an understanding easy, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this.
The invention according to claim 1 defines an aperture through which incident subject light passes, and a plurality of aperture blades (30) arranged in a predetermined direction and a desired aperture. Driving means (20, 40) for opening / closing the plurality of aperture blades according to a desired aperture value, and the adjacent apertures when opening / closing the aperture blades by the driving means so as to have an opening size The diaphragm device (4, 4A) is characterized by comprising separation means (50, 50A, 50B, 60) for separating the blades.
The invention according to claim 2 is the diaphragm device (4) according to claim 1, wherein the separating means (50, 50A, 50B) is a first protrusion provided on the diaphragm blade (30). (51) and when the apertures are opened and closed by the drive means (20, 40), the first apertures are pressed in the predetermined direction to separate adjacent aperture blades in the predetermined direction. And two protrusions (52).
The invention according to claim 3 is the diaphragm device (4) according to claim 2, wherein the second protrusion (52) has a plurality of diaphragm blades (30) having a specific diaphragm value. It has a non-projection part (52a) fitted with the 1st projection part so that the 1st projection part (30) may not be pressed in the predetermined direction in the position.
According to a fourth aspect of the present invention, there is provided the diaphragm device (4A) according to the first aspect, wherein the separating means 60) includes a piezoelectric element that is deformed by application of a predetermined voltage, and when the predetermined voltage is applied. Is characterized in that the adjacent diaphragm blades are separated from each other by elongating and deforming and pressing the diaphragm blades in the predetermined direction.
A fifth aspect of the present invention is the diaphragm device according to any one of the first to fourth aspects, wherein the separating means (50, 50A, 50B, 60) drives the diaphragm blade (30). It is provided in the vicinity of the base point (32).
According to a sixth aspect of the present invention, the diaphragm device (4, 4A) according to any one of the first to fifth aspects and the incident subject light are refracted to form a subject image on the exit side. A lens barrel (2), comprising: an optical member (3); and a cylindrical body in which the diaphragm device and the optical member are accommodated.
Note that the configuration described with reference numerals may be improved as appropriate, or at least a part thereof may be replaced with another component.

  According to the present invention, it is possible to provide a diaphragm device and a lens barrel that can reduce the operation sound of the diaphragm blades.

Embodiments of a diaphragm device and a lens barrel according to the present invention will be described below with reference to the drawings. In the drawings used for the following description, an XYZ orthogonal coordinate system is appropriately provided for easy explanation and understanding. In this coordinate system, the direction toward the left as viewed from the photographer at the camera position (hereinafter referred to as the normal position) when the photographer shoots a horizontally long image with the optical axis L1 being horizontal is defined as the X plus direction. Further, the direction toward the upper side in the normal position is defined as the Y plus direction. Further, the direction toward the subject at the normal position is taken as the Z direction. It should be noted that the shapes, lengths, thicknesses, and the like of the respective portions shown in the embodiments do not necessarily match the actual ones, and portions that are not necessary for description are appropriately omitted or simplified.
(Embodiment 1)

  FIG. 1 is a schematic diagram of a lens barrel 2 provided with a diaphragm device 4 according to the first embodiment and a camera 1 to which the lens barrel 2 is attached. The lens barrel 2 of the present embodiment includes a lens 3 as an optical member that refracts incident subject light and forms a subject image on the exit side, and a diaphragm device 4 that adjusts the aperture size of the lens 3. These are accommodated in the cylinder 7. The camera 1 also includes a camera body 5 and an imaging unit 6 that captures a subject image formed by the lens 3 and converts it into an electrical signal. The lens barrel 2 is detachably attached to the camera body 5. It has become.

  FIG. 2 is a perspective view showing a state in which the diaphragm device 4 of the present embodiment is assembled, and FIG. 3 is an exploded perspective view thereof. As shown in FIG. 3, the diaphragm device 4 includes a pressing plate 10 having a circular opening 11 at the center, a cam plate 20 having a circular opening 21 at the center, a plurality of diaphragm blades 30, And a fixed ring 40 having a circular opening 41. The pressing plate 10, the cam plate 20, the diaphragm blade 30, and the stationary ring 40 are arranged with the optical axis L1 as the center.

The cam plate 20 is a rotating member in which a plurality of cam grooves 22 that engage with the cam shaft 31 of the aperture blade 30 are formed. The cam plate 20 is provided with an arm 23, and the arm 23 is driven to rotate about the optical axis L1, whereby a plurality of diaphragm blades 30 are simultaneously driven. The arm 23 is connected to an actuator (not shown), and when reducing the aperture size of the subject light, the arm 23 rotates about the optical axis L1 in the direction A (see FIG. 3), and conversely the aperture size of the subject light. When the value is increased, it is configured to rotate in the direction B in the figure.
The mechanism including the actuator, the cam plate 20, and the fixed ring 40 functions as a driving unit that opens and closes the plurality of aperture blades 30 according to a desired aperture value so that the aperture of the lens 3 has a desired aperture size. To do.

  The diaphragm blades 30 are formed of a thin plate member such as metal or resin, and are arranged so as to overlap each other in the direction of the optical axis L1. The diaphragm blade 30 is provided with a cam shaft 31 that engages with the cam groove 22 of the cam plate 20 and a rotary shaft 32 that engages with the shaft hole 42 of the stationary ring 40. The shape of the diaphragm blade 30 and the planar positional relationship between the cam shaft 31 and the rotating shaft 32 are shown in FIG.

  The fixed ring 40 is a member fixedly disposed inside the lens barrel 2, and a shaft hole 42 into which the rotation shaft 32 of the diaphragm blade 30 is inserted, and an escape groove 43 that serves as a relief of the cam shaft 31 of the diaphragm blade 30. And are formed. The plurality of diaphragm blades 30 are accommodated between the fixed ring 40 and the cam plate 20, and the presser plate 10 is fitted from the outside of the cam plate 20 to be fitted to the outer peripheral portion of the fixed ring 40. As shown in FIG. 2, an integrated assembly part is obtained. The operation of the diaphragm blade 30 will be described later.

  FIG. 4 is a front view of the diaphragm device 4 according to the first embodiment. In FIG. 4, the presser plate 10 and the cam plate 20 are omitted for easy understanding of the internal structure. However, the position of the cam groove 22 formed in the cam plate 20 is indicated by a one-dot chain line. Moreover, although only one aperture blade 30 is drawn, in reality, seven diaphragm blades 30 are equally arranged along the circumference. 5, FIG. 7, and FIG. 9 used in the following description are also drawn in such a form.

  As shown in FIG. 4, a diaphragm blade separation portion 50 that separates adjacent diaphragm blades 30 when the diaphragm blades 30 are opened and closed is provided on the inner side (back surface side) of the diaphragm blades 30. In FIG. 4, the blade separation portion 50 is drawn only at the position where the diaphragm blade 30 is drawn, but the blade separation portion 50 having the same configuration is provided at the position of each diaphragm blade 30.

  Next, the configuration of the blade separating portion 50 will be described. FIG. 5 is a partially enlarged view of FIG. As shown in FIG. 5, the blade separating portion 50 is provided in the vicinity of the rotation shaft 32 that is the driving base point of the diaphragm blade 30. The reason why the blade separating portion 50 is provided in the vicinity of the rotating shaft 32 is to efficiently reduce the operating noise generated when the diaphragm blades 30 rub against each other. That is, when the diaphragm blades 30 are driven so as to reduce the aperture size of the subject light, the contact area between the diaphragm blades 30 is large at the tip portion and small at the root portion. The operation sound generated by rubbing the diaphragm blades 30 is larger at the tip portion having a larger contact area than the root portion having a smaller contact area. For this reason, by lifting the base portion of each diaphragm blade 30 and separating the diaphragm blades 30 from each other, the contact area between the diaphragm blades 30 at the tip portion can be reduced without interfering with the rotation operation of each diaphragm blade 30. Can do. Therefore, it is possible to efficiently reduce the operation sound generated when the diaphragm blades 30 rub against each other.

  Further, since the diaphragm blade 30 is harder at the root portion than the tip portion, the operation sound generated by rubbing the diaphragm blades 30 is smaller because the root portion is less likely to vibrate than the thin soft tip portion. . That is, when the diaphragm blades 30 are lifted and separated from each other by lifting the base portions of the diaphragm blades 30, the distance between the root portions is smaller than that of the tip portion. As a result, the operating noise due to rubbing can be reduced.

  Further, the blade separating portion 50 is disposed so as to form a part of an arc centered on the rotation shaft 32. This is for the purpose of maintaining the engagement between the first protrusion 51 and the second protrusion 52 when the diaphragm blade 30 rotates about the rotation shaft 32. Further, when the diaphragm blade 30 rotates about the rotation shaft 32, the position where the diaphragm blade 30 is pressed in the Z direction of the optical axis L1 is set to be substantially the same distance from the rotation shaft 32.

  6A to 6C are schematic cross-sectional views of the blade separating portion 50 shown in FIG. As shown in FIG. 5, the blade spacing portion 50 is formed in a circular arc shape in a plan view, but is drawn linearly in FIG.

  As shown in FIG. 6A, the blade spacing portion 50 of the present embodiment includes a plurality of first protrusions 51 provided on the back surface side of the diaphragm blade 30, that is, the side facing the fixed ring 40, and a fixed ring. The plurality of second protrusions 52 provided on the surface facing the 40 diaphragm blades 30 are alternately arranged so as to have a circular arc shape in a plan view. The 1st projection part 51 is a hemispherical convex part, and is formed in one with the diaphragm blade 30 in this embodiment. The 2nd projection part 52 is a prismatic convex part, and is formed in one with the fixed ring 40 in this embodiment. However, the 1st projection part 51 and the 2nd projection part 52 which affixed what each was produced as a separate component by adhesion | attachment etc. may be sufficient.

  FIG. 6A shows a state where the aperture blade 30 is stored (see FIG. 4). In this state, since the first protrusions 51 and the second protrusions 52 are engaged with each other so as to be alternately arranged, adjacent diaphragm blades 30 are in contact with each other. From this state, when the aperture blade 30 is rotationally driven in a direction to reduce the aperture size of the aperture through which the subject light passes, the first projection 51 moves in the horizontal direction with respect to the second projection 52. The first protrusion 51 rides on the tip of the two protrusions 52, and the first protrusion 51 and the second protrusion 52 come into contact with each other. In this state, since the first protrusion 51 is pressed by the second protrusion 52 in the Z direction of the optical axis L1 (see FIG. 3), the adjacent diaphragm blades 30 are separated from each other in the Z direction of the optical axis L1. become.

  Further, as shown in FIG. 6A, between the adjacent second projections 52, the first projection 51 is placed in the Z direction of the optical axis L1 at a position where the diaphragm blade 30 has a specific aperture value. A non-projecting portion 52a that fits with the first projecting portion 51 is formed so as not to be pressed. This non-projection part 52a is formed as a part of the 2nd projection part 52, and is the same surface (flat part) as the surface of the stationary ring 40, as shown to Fig.6 (a). However, the height of the non-projection portion 52 a is appropriately determined within a range where it does not contact the first projection portion 51.

  In the state where the first protrusion 51 is fitted to the non-protrusion 52a, the first protrusion 51 is not pressed in the Z direction of the optical axis L1, so that the adjacent diaphragm blades 30 are not separated from each other and are in contact with each other. Become. On the other hand, in the state where the first protrusion 51 and the second protrusion 52 are in contact with each other, the first protrusion 51 is pressed in the Z direction of the optical axis L1, so that the adjacent diaphragm blades 30 are separated from each other. In a non-contact state.

  The interval in the arrangement direction of the adjacent second protrusions 52 is set to a position where a specific aperture value is obtained when the plurality of aperture blades 30 are rotationally driven. That is, when the aperture value changes from the fully open position to “2.8”, “4”, “5.6”, “8”, “11”,..., The state shown in FIG. When the first protrusion 51 moves horizontally one by one and engages with the non-protrusion 52a, the aperture size through which the subject light passes is reduced by one step from the above aperture value, and the amount of light is 1 Each time the step is reduced, the number is reduced by ½.

  According to the above configuration, only when the diaphragm blades 30 are rotationally driven, the adjacent diaphragm blades 30 are separated from each other. When the diaphragm blades 30 are stopped at a specific aperture value, the adjacent diaphragm blades 30 are separated from each other. It becomes a contact state.

  FIG. 6B is a schematic cross-sectional view showing another configuration example of the blade separating portion, and the same reference numerals are given to the same configurations as those in FIG. In the blade separation portion 50A of this configuration example, the second protrusion base 53 in which the second protrusion 52 and the non-protrusion 52a are integrally formed is attached to the surface of the stationary ring 40 by adhesion. In this configuration example, since the second protrusion base 53 including the second protrusion 52 and the non-protrusion 52a is used, the second protrusion 52 and the non-protrusion 52a are individually formed on the stationary ring 40. Compared with what was done, the arrangement | positioning and shape of the 2nd projection part 52 and the non-projection part 52a can be easily changed according to the arrangement number and shape of the 1st projection part 51. FIG. Also in this configuration example, the height of the non-projection part 52 a is appropriately determined within a range where it does not contact the first projection part 51.

  FIG. 6C is a schematic cross-sectional view showing still another configuration example of the blade separating portion, and the same reference numerals are given to the same configurations as those in FIG. In the blade separation portion 50B of this configuration example, the second protrusion base 54 in which the second protrusion 52 and the non-protrusion 52b are integrally formed is attached to the surface of the stationary ring 40 by adhesion. The non-projection part 52b of the present configuration example has a substantially V-shaped cross section instead of a concave shape. By setting it as such a cross-sectional shape, the frictional resistance when the 1st projection part 51 moves to a horizontal direction, getting over the 2nd projection part 52 can be reduced. In addition, wear of the first protrusion 51 can be reduced.

  Next, the operation of the diaphragm device 4 configured as described above will be described with reference to FIGS. FIG. 7 is a front view of the diaphragm device 4 when the diaphragm blade 30 is rotationally driven, and the same parts as those in FIG. 4 are denoted by the same reference numerals. When the cam plate 20 (not shown) is driven to rotate counterclockwise from the state of FIG. 4, the cam groove 22 formed in the cam plate 20 also rotates counterclockwise. Since the cam groove 22 is engaged with the cam shaft 31 of the diaphragm blade 30, the cam shaft 31 moves in the counterclockwise direction along the cam groove 22.

  As a result, as shown in FIG. 7, the diaphragm blade 30 rotates counterclockwise around the rotation shaft 32. Since the cam plate 20 (not shown) is engaged with the cam shafts 31 of all the diaphragm blades 30, when the cam plate 20 (not shown) is rotated counterclockwise as described above, all the diaphragm blades 30 are It rotates counterclockwise around the rotation shaft 32. Therefore, the aperture through which the subject light passes is closed, and the aperture size is reduced. When the cam plate 20 (not shown) is driven to rotate clockwise, the operation is opposite to that described above, and all the aperture blades 30 rotate clockwise about the rotation shaft 32. Therefore, as shown in FIG. 4, the opening through which the subject light passes is opened, and the opening size is increased.

  Next, the operation of the blade separating portion 50 when the diaphragm blade 30 is rotationally driven as described above will be described. 8A and 8B are side views showing the blade separating portion 50 when the diaphragm blade 30 is rotationally driven. As shown in FIG. 8A, at the position where the diaphragm blades 30 are housed (see FIG. 4), the first protrusions 51 and the second protrusions 52 are engaged so as to be alternately arranged. In other words, since the first protrusion 51 is engaged with the non-protrusion 52a, the first protrusion 51 is not pressed in the Z direction of the optical axis L1 by the second protrusion 52, and the adjacent diaphragm The blades 30 are in contact with each other.

  On the other hand, when the diaphragm blade 30 is rotationally driven in a direction to reduce the aperture size of the aperture through which the subject light passes, the first projection 51 moves in the horizontal direction with respect to the second projection 52, and therefore FIG. As shown in b), the first protrusion 51 rides on the tip of the second protrusion 52, and the first protrusion 51 and the second protrusion 52 are in contact with each other. In this state, since the second protrusion 52 presses the first protrusion 51 in the Z direction, the adjacent diaphragm blades 30 are separated from each other in the Z direction of the optical axis L1. Therefore, a gap G is formed between adjacent aperture blades 30. Thereafter, when the aperture blade 30 reaches a position where the aperture value reaches a specific aperture value, the first projection 51 is fitted with a non-projection 52a (not shown), so that the second projection 52 is shown in FIG. Does not press the first protrusion 51 in the Z direction of the optical axis L1, and the adjacent diaphragm blades 30 come into contact with each other.

According to the said Embodiment 1, there exist the following effects.
(1) When the diaphragm blades 30 are opened and closed, the adjacent blades 30 are separated from each other by the blade separating portion 50 to form a gap, so that the operation noise due to friction between the diaphragm blades can be reduced. Therefore, even when the diaphragm device 4 operates in the moving image shooting mode, the operation sound due to the friction between the diaphragm blades is not recorded as noise, and the deterioration of the recorded image quality can be prevented. In addition, since the operation sound due to friction between the diaphragm blades is generated not only when the diaphragm blades 30 are closed to a desired opening size but also when the closed diaphragm blades 30 are opened, the operation noise is continuously generated as in the operation shooting mode. This is effective when the diaphragm blade 30 is rotationally driven.
(2) Since the blade separation portion 50 includes the first protrusion 51 provided on the diaphragm blade 30 and the second protrusion 52 provided on the stationary ring 40, electrical control is not required for driving. In addition, the structure can be simplified. Therefore, it can be manufactured at low cost.
(3) As shown in FIG. 6A, when the first protrusion 51 is formed integrally with the diaphragm blade 30 and the second protrusion 52 is formed integrally with the stationary ring 40, each is separated. The number of parts can be reduced as compared with the case where a part manufactured as a part is attached by bonding or the like, and the man-hours for manufacturing can be reduced.
(4) As shown in FIG. 6B, when the second protrusion base 53 having the second protrusions 52 and the non-protrusions 52a is used, the number and shape of the first protrusions 51 are adjusted. The arrangement and shape of the second protrusion 52 and the non-protrusion 52a can be easily changed.
(5) As shown in FIG. 6C, when the cross-sectional shape of the non-projecting portion 52b is substantially V-shaped, the first projecting portion 51 moves in the horizontal direction while getting over the second projecting portion 52. Since the frictional resistance can be reduced, it is possible to reduce the operating noise generated in the blade separating portion 50B. Moreover, since the wear of the first protrusion 51 is reduced, the operation can be stabilized over a long period of time, and the durability can be improved.
(6) A non-projection portion 52a that fits the first projection portion 51 is provided so that the first projection portion 51 is not pressed in the Z direction of the optical axis L1 at a position where the diaphragm blade 30 has a specific aperture value. Therefore, when the diaphragm blades 30 are stopped at the position of the desired diaphragm value, adjacent diaphragm blades 30 are in contact with each other, and light can be prevented from leaking from the gap between the diaphragm blades 30. Thereby, it is possible to prevent the image quality of the captured image from being deteriorated.
(7) Since the blade separation portion 50 is provided in the vicinity of the rotation shaft 32 that is the driving base point of the diaphragm blade 30, the contact area between the diaphragm blades 30 at the tip portion is prevented without hindering the rotation operation of the diaphragm blade 30. Can be small. Therefore, it is possible to efficiently reduce the operation sound generated when the diaphragm blades 30 rub against each other. Further, according to the above configuration, the driving load of the actuator can be reduced, so that power saving can be achieved.

Further, since the diaphragm blade 30 is harder at the root portion than the tip portion, the operation sound generated by rubbing the diaphragm blades 30 is smaller at the root portion than at the thin soft tip portion. For this reason, when the diaphragm blades 30 are lifted at their root parts and the diaphragm blades 30 are separated from each other, the distance between the root parts is smaller than that of the tip part, but since this part originally has less operating noise due to rubbing, As a whole, the operation noise due to rubbing can be reduced.
(8) Since the blade separating portion 50 is disposed so as to form a part of an arc centered on the rotation shaft 32, the first protrusion portion is formed when the diaphragm blade 30 rotates around the rotation shaft 32. The engagement between the first protrusion 51 and the second protrusion 52 can be maintained. Further, with such an arrangement, when the diaphragm blade 30 rotates about the rotation shaft 32, a position where the diaphragm blade 30 is pressed in the Z direction of the optical axis L1, that is, a position where the diaphragm blade 30 is lifted is set. The distance can be substantially the same from the rotation shaft 32. According to this, when the diaphragm blades 30 rotate around the rotation shaft 32, the distances between the adjacent diaphragm blades 30 can be made substantially equal regardless of the rotational position.
(Embodiment 2)

  FIG. 9 is a front view of the diaphragm device 4A according to the second embodiment. As described above, FIG. 9 is also illustrated by omitting the pressing plate 10 and the cam plate 20 as in FIG. In the present embodiment, the stationary ring 40 is provided with a blade separation portion 60 made of a piezoelectric element that is deformed by applying a predetermined voltage. The blade separating portion 60 expands and deforms when a predetermined voltage is applied, and presses the diaphragm blade 30 in the Z direction of the optical axis L1 (see FIG. 3) to separate adjacent diaphragm blades 30 from each other. Is.

  In the present embodiment, the planar shape of the blade separating portion 60 is a shape that forms a part of an arc centered on the rotation shaft 32. This is to make the position where the diaphragm blade 30 is pressed in the Z direction of the optical axis L1 at substantially the same distance from the rotation shaft 32 when the diaphragm blade 30 rotates about the rotation shaft 32. However, since the blade spacing portion 60 of the present embodiment is not configured to engage the protrusions arranged vertically as in the first embodiment, the blade spacing portion 60 may have a shape that is straight on a plane. . Further, in FIG. 9, the blade separation portion 60 is drawn only at the position where the diaphragm blade 30 is drawn, but the blade separation portion 60 having the same configuration is provided at the position of each diaphragm blade 30 on the stationary ring 40. .

  In addition, voltage supply lines 61 and 62 for applying positive and negative voltages are connected to the piezoelectric elements constituting the blade separating portion 60. These wirings penetrate the back side of the stationary ring 40 and are connected to voltage supply annular lines 71 and 72 that are also wired along the outer periphery of the stationary ring 40. The voltage supply annular lines 71 and 72 are connected to a voltage supply unit 73 disposed on the back surface of the fixed ring 40. The voltage supply unit 73 applies a predetermined voltage in synchronization with the rotation of the plurality of diaphragm blades 30 and performs control to stop the application of the voltage at a position where the specific aperture value is obtained. . A piezoelectric element is a member having a characteristic that it expands and deforms by application of a predetermined voltage and returns to its original length when the application of voltage is stopped.

  Also in this embodiment, the adjacent diaphragm blades 30 are separated only when the diaphragm blades 30 are rotationally driven, and when the diaphragm blades 30 are stopped at a specific aperture value, the adjacent diaphragm blades 30 are separated from each other. It becomes a contact state.

  Next, the operation of the diaphragm device 4A configured as described above will be described with reference to FIGS. Note that the cam mechanism for rotationally driving the aperture blade 30 is the same as that of the first embodiment, and thus the description thereof is omitted.

  10A and 10B are side views showing the blade separating portion 60 when the diaphragm blade 30 is rotationally driven. Among these, in FIG. 10A, the connection between the voltage supply lines 61 and 62 and the voltage supply annular lines 71 and 72 is schematically shown.

  As shown in FIG. 10A, at the position where the diaphragm blade 30 is accommodated (see FIG. 9), the piezoelectric element of the blade separation portion 60 has a length before expansion and deformation. The diaphragm blades 30 adjacent to each other are in contact with each other without being pressed in the Z direction of L1.

  On the other hand, when the diaphragm blade 30 is rotationally driven in a direction to reduce the aperture size of the aperture through which the subject light passes, a predetermined voltage is applied from the voltage supply unit 73 (see FIG. 9) to the piezoelectric elements constituting the blade separation unit 60. Is done. As a result, the piezoelectric element expands and deforms and presses the diaphragm blades 30 in the Z direction of the optical axis L1, so that the adjacent diaphragm blades 30 are separated from each other in the Z direction of the optical axis L1, as shown in FIG. Will do. Therefore, a gap G is formed between adjacent aperture blades 30. Thereafter, when the aperture blade 30 reaches a position where the aperture value reaches a specific aperture value, the application of the voltage from the voltage supply unit 73 stops, and as shown in FIG. Stops pressing the diaphragm blades 30 in the Z direction of the optical axis L1, and the adjacent diaphragm blades 30 come into contact with each other.

According to the second embodiment, the following effects are obtained.
(1) When the aperture blades 30 are opened and closed, the adjacent blades 30 are separated from each other by the blade separating portion 60 and a gap is formed, so that it is possible to reduce operating noise due to friction between the aperture blades 30. Therefore, even when the diaphragm device 4 is operated in the moving image shooting mode, the operation sound due to the friction between the diaphragm blades 30 is not recorded as noise, and deterioration of the recorded image quality can be prevented.
(2) Since the blade spacing portion 60 is configured by a piezoelectric element, mechanical wear can be reduced as compared with the configuration of the first embodiment. Therefore, the operation can be stabilized over a long period of time and the durability can be improved. Moreover, the operation sound itself generated at the blade separating portion 60 can be reduced.
(3) Since the operation position of the blade separating portion 60 can be electrically controlled, when the diaphragm blade 30 is rotationally driven, a position for pressing the diaphragm blade 30 in the Z direction of the optical axis L1 is arbitrarily set. be able to.
(Deformation)

As described above, the present invention is not limited to the embodiment described above, and various modifications and changes as shown below are possible, and these are also within the scope of the present invention.
(1) Although the configuration in which the cam plate 20 is rotated by the arm 23 has been described in the first embodiment, the cam plate 20 may be driven by a motor. For example, a segment gear may be provided on the outer edge portion of the cam plate 20, meshed with a pinion gear connected to the stepping motor, and the cam plate 20 rotated by the rotational force of the stepping motor.
(2) In the first embodiment, the first protrusion 51 may be provided on the stationary ring 40 and the second protrusion 52 may be provided on the diaphragm blade 30.
(3) In Embodiment 2, it is good also as a structure which provided the same 1st projection part 51 as Embodiment 1 in the back surface of the aperture blade 30. FIG. In addition, the blade separating portion 60 may be configured by arranging a plurality of piezoelectric elements in an arc shape centering on the rotation shaft 32. Further, the blade separating portion 60 may be configured by a piezoelectric blower instead of the piezoelectric element.
(4) In each of the embodiments described above, an example in which seven diaphragm blades 30 are provided has been described. However, the number of diaphragm blades 30 is not limited to seven, and may be more than that. It may be less than that.
(5) In each of the above embodiments, the example in which the aperture device and the lens barrel according to the present invention are applied to a digital camera in which the lens barrel is detachably attached to the camera body has been described. However, the present invention is not limited to this. For example, the present invention can also be applied to a lens-integrated camera, a diaphragm device provided in a video camera, and a lens barrel.

  In addition, although the said embodiment and modification can be used in combination as appropriate, since the structure of each embodiment is clear by illustration, detailed description is abbreviate | omitted. Further, the present invention is not limited to the embodiment described above.

FIG. 2 is a schematic diagram of a lens barrel including the aperture device of Embodiment 1 and a camera equipped with the lens barrel. It is a perspective view which shows the state which assembled the aperture_diaphragm | restriction apparatus of Embodiment 1. FIG. FIG. 3 is an exploded perspective view of FIG. 2. It is a front view of the diaphragm | throttle device in Embodiment 1. FIG. It is the elements on larger scale of FIG. (A)-(c) is a schematic sectional drawing of the blade | wing separation | spacing part shown in FIG. It is a front view of a diaphragm | throttle device when rotating a diaphragm blade. (A), (b) is a side view which shows the blade | wing separation part of Embodiment 1 when an aperture blade is rotationally driven. 6 is a front view of a diaphragm device according to Embodiment 2. FIG. (A), (b) is a side view which shows the blade separation part of Embodiment 2 when a diaphragm blade is rotationally driven.

Explanation of symbols

  1: camera, 2: lens barrel, 3: lens, 4, 4A: aperture device, 20: cam plate, 30: aperture blade, 31: cam shaft, 32: rotating shaft, 40: fixed ring, 22, 43: Relief groove, 42: shaft hole, 50, 50A, 50B, 60: blade separating portion, 51: first protrusion, 52: second protrusion, 52a: non-protrusion, 53, 54: second protrusion base, 61 62: Voltage supply line 71, 72: Voltage supply ring line 73: Voltage supply unit

Claims (6)

A plurality of aperture blades that define an aperture through which incident subject light passes, and are arranged so as to overlap each other in a predetermined direction,
Driving means for opening and closing the plurality of diaphragm blades according to a desired aperture value so that the aperture has a desired aperture size;
Separating means for separating adjacent diaphragm blades when the diaphragm blades are opened and closed by the driving means; and
A diaphragm device comprising: The aperture device according to claim 1,
The spacing means is
A first protrusion provided on the diaphragm blade;
A second protrusion that separates adjacent diaphragm blades in the predetermined direction by pressing the first protrusion in the predetermined direction during the opening / closing drive of the diaphragm blades by the driving means;
A diaphragm device comprising: The diaphragm device according to claim 2, wherein
The second protrusion is
Having a non-projecting portion that fits with the first projecting portion so as not to press the first projecting portion in the predetermined direction at a position where the plurality of diaphragm blades have a specific aperture value;
A diaphragm device characterized by. The aperture device according to claim 1,
The spacing means is
It consists of a piezoelectric element that deforms when a predetermined voltage is applied, and when the predetermined voltage is applied, the adjacent diaphragm blades are separated from each other by expanding and deforming and pressing the diaphragm blades in the predetermined direction.
A diaphragm device characterized by. The diaphragm device according to any one of claims 1 to 4,
The diaphragm device according to claim 1, wherein the separating means is provided in the vicinity of a drive base point of the diaphragm blade. A diaphragm device according to any one of claims 1 to 5,
An optical member that refracts incident subject light to form a subject image on the exit side;
A cylinder in which the diaphragm device and the optical member are housed;
A lens barrel comprising:

Images