JP5330107B2 - Aperture device - Google Patents

Description

  The present invention relates to an aperture device that includes a plurality of aperture blades that are disposed in an optical device and change the amount of passing light by being displaced.

  2. Description of the Related Art Conventionally, a diaphragm device disposed in an optical device such as a camera has a cam groove formed on a plurality of diaphragm blades rotatably disposed on a support shaft, and a cam follower that is engaged with the cam groove is provided. In addition to the plurality of diaphragm blades adjusting the optical path opening amount by the rotation of the rotating member, a cam groove is formed on the rotating member side, and the cam follower engaged with the cam groove is formed into the plurality of diaphragm blades. What is provided in is known.

  Such various diaphragm devices have a configuration in which a cam follower is provided on the diaphragm blade, and a pin-shaped cam follower must be caulked on the diaphragm blade. Goods may be adopted.

  For example, as in the iris diaphragm device disclosed in Patent Document 1, a plurality of diaphragm blades each having a cam groove that is a long hole that fits into a pin of the blade operation member are overlapped in a scale shape, It is well known that a plurality of aperture blades are rotated around a support shaft in accordance with the operation to change an arbitrary aperture opening amount.

  Further, for example, an optical path opening and closing device that is a diaphragm device disclosed in Patent Document 2 is provided with a plurality of fulcrum pins serving as rotation centers of a plurality of blade members on a windmill, and a rack that meshes with a pinion of a motor on the windmill. By forming the device, the size of the base plate is reduced so as not to interfere with the fulcrum pin and the rack, thereby reducing the size of the apparatus.

Japanese Utility Model Publication No. 60-78016 JP 2007-663827 A

  However, in the iris diaphragm device of Patent Document 1, even if the diaphragm is made small, the cam groove, which is a long hole formed in a plurality of diaphragm blades, does not enter the subject light beam, that is, outside the intrinsic aperture. A cam groove is formed, which hinders downsizing of the apparatus.

  On the other hand, in the optical path opening and closing device of Patent Document 2, the cam groove of the diaphragm blade enters the optical path opening as the diaphragm amount decreases, but the cam groove portion entering the optical path opening is covered with another diaphragm blade. Shielded with light.

  However, in the optical path opening / closing device of Patent Document 2, since the cam groove portion that enters the optical path opening needs to be covered with another diaphragm blade, the shape of the diaphragm blade must be increased, which hinders downsizing of the device. It is a factor. In addition, since it is necessary not to interfere with the cam followers engaged in the cam grooves of other diaphragm blades, it is difficult to reduce the size of the device if the shape of the diaphragm blades is increased.

  Therefore, the present invention has been made in view of the above circumstances, and the object of the present invention is to reduce the diameter of the optical path as the aperture diameter decreases, even if the plurality of aperture blades formed with the cam grooves are reduced. It is another object of the present invention to provide a diaphragm device that can be miniaturized by completely shielding the cam groove whose amount of entry increases.

Throttle device according to one aspect of the present invention, the diaphragm device having a plurality of diaphragm blades overlap each other, and an opening member having an opening and centered on the optical axis of the photographing optical system, provided on an outer side of the opening Together with the first support shaft, the second support shaft provided at the circumferential position around the optical axis different from the first support shaft outside the opening, and the second support shaft A third position provided at a circumferential position centering on the optical axis different from the first support shaft and the second support shaft outside the opening so as to sandwich the first support shaft. support shaft and said first drive shaft disposed on the optical axis in the direction from the first support shaft, a second disposed on the optical axis in the direction from the second support shaft a drive shaft, anda third drive shaft disposed on the optical axis in the direction from the third support shaft, said first drive shaft, said second drive shaft, and the second A drive member that reciprocally moves the drive shaft about the optical axis, a first rotary hole that is one of the diaphragm blades and is rotatably fitted to the first support shaft, and the first When the first drive shaft is inserted and the drive member is driven, the amount of rotation of the first drive shaft about the optical axis is controlled according to the amount of movement of the first drive shaft about the optical axis , and the subject A first cam groove that can enter the light beam, and the first cam groove that enters the subject light beam in accordance with the rotation around the first spindle controlled by the first cam groove. A diaphragm blade, one of the diaphragm blades different from the first diaphragm blade, a second rotation hole rotatably fitted to the second support shaft, and the second drive shaft Is inserted, and the drive member is driven to rotate the second drive shaft around the second support shaft in accordance with the amount of movement of the second drive shaft around the optical axis. To control the amount, the second possible approach in the subject light flux having a cam groove, and with the rotation of said controlled by the cam groove of the second second support shaft around the first diaphragm blade is accompanied to enter into the object light beam, and a second diaphragm blade for shielding a part in the subject light flux of the first cam groove, the first diaphragm blade, and the second It is one of the diaphragm blades different from the diaphragm blades, and a third rotation hole that is rotatably fitted to the third support shaft and the second drive shaft are fitted, and the drive member is A third cam groove capable of entering the subject luminous flux by controlling the amount of rotation about the third support shaft in accordance with the amount of movement of the third drive shaft about the optical axis by being driven. And as the first diaphragm blades enter the luminous flux of the subject, the second diaphragm blades cannot shield the light. And comprising a third diaphragm blade for shielding the remaining non-shielding balance in the subject light flux of the first cam groove, the.

  According to the present invention, even if the plurality of diaphragm blades in which the cam grooves are formed are reduced, the cam grooves that increase the amount of entry into the optical path opening can be completely shielded as the diaphragm diameter is reduced. An aperture device that can be miniaturized can be provided.

The perspective view which shows the structure of the aperture_diaphragm | restriction apparatus of one embodiment of this invention. 1 is an exploded perspective view of the diaphragm device of FIG. A plan view showing the configuration of the diaphragm blade The top view for demonstrating rotation of an aperture blade same as the above The top view which shows the aperture blade with the open aperture fully opened FIG. 5 is a plan view showing the diaphragm blades in a state in which the first intermediate diaphragm is defined by turning from FIG. 5 in a closing direction by a predetermined angle. FIG. 6 is a plan view showing the diaphragm blades in a state in which the second intermediate diaphragm is defined by turning from FIG. 6 in a closing direction by a predetermined angle. FIG. 7 is a plan view showing the diaphragm blades in a state where the third intermediate diaphragm is defined by turning from FIG. 7 in a closing direction by a predetermined angle. FIG. 8 is a plan view showing the diaphragm blades in a state in which the fourth intermediate diaphragm is defined by turning from FIG. 8 in a closing direction by a predetermined angle. The top view showing the diaphragm blade in the minimum diaphragm state The top view which shows three aperture blades of the state rotated to the direction which closes at a predetermined angle similarly Same as above, enlarged view of circle XII in FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 is a perspective view showing the configuration of the diaphragm device, FIG. 2 is an exploded perspective view of the diaphragm device of FIG. 1, FIG. 3 is a plan view showing the configuration of the diaphragm blades, and FIG. 4 is for explaining the rotation of the diaphragm blades. FIG. 5 is a plan view showing the diaphragm blades in the maximum open state, and FIG. 6 is a plan view showing the diaphragm blades in a state in which the first intermediate diaphragm is defined by turning from FIG. FIGS. 7 and 7 are plan views showing the diaphragm blades in a state in which the second intermediate diaphragm is defined by turning from FIG. 6 in the direction of closing by a predetermined angle, and FIG. 8 is turning in the direction of closing by a predetermined angle from FIG. FIG. 9 is a plan view showing the diaphragm blade in a state in which the third intermediate diaphragm is defined. FIG. 9 is a diagram showing a state in which the diaphragm blade in a state in which the fourth intermediate diaphragm is defined by turning from FIG. FIG. 10 is a plan view showing the diaphragm blade in the minimum diaphragm state, and FIG. 11 is closed at a predetermined angle. Plan view showing a three-blade throttle state of being rotated in the direction, FIG. 12 is an enlarged view of a circle XII part in Fig. 11.

  In the following description, the optical axis of the photographing lens that is the photographing optical system of the camera of the present embodiment is O, the subject side is the front side, and the imaging side is the rear side (back side). The rotation direction will be described as a clockwise direction or a counterclockwise direction as viewed from the subject side.

The diaphragm device 1 of the present embodiment shown in FIGS. 1 and 2 is provided in a camera lens barrel (not shown), a camera body, or the like in order to adjust the amount of light passing through the optical system.
As shown in FIG. 1, the diaphragm device 1 includes a blade holder 2 positioned at the front, a diaphragm frame 3 fitted to the back side of the blade holder 2 and fixed by a fixing screw 8, and the diaphragm frame 3. And a disposed motor 4.

  In addition, as shown in FIG. 2, the diaphragm device 1 includes a plurality of, in this case, seven diaphragm blades 6 that overlap each other in order from the front between the blade presser 2 and the diaphragm frame 3. The diaphragm blade group 5 and the diaphragm plate 7 that is rotatably engaged with the diaphragm frame 3 are sandwiched.

  The blade retainer 2 is a plate formed by injection molding with a resin such as a metal or a plastic colored so as to have a light-shielding property, with a round optical path opening 11 defining the fully open state of the aperture stop formed at the center. The opening member of a shape is comprised. The periphery of the optical path opening 11 in the thick part of the blade retainer 2 has a tapered shape that squeezes from the front to the rear. In addition, although the aperture stop device 1 of this Embodiment is prescribed | regulated as an open aperture | diaphragm | restriction by the optical path opening part 11 of the blade | wing holding | suppressing 2, it does not limit to this but the aperture stop mentioned later in each aperture blade 6 of the aperture blade group 5 It is good also as a structure which prescribe | regulates an open aperture_diaphragm | restriction with the formation edge 26 (refer FIG. 3).

  Further, the blade presser 2 is formed with a screw hole portion 12 through which the fixing screw 8 is inserted in two upper and lower portions and two defining hole portions 13 that define a fitting position with the diaphragm frame 3. Further, the blade presser 2 is provided with seven pin fitting holes 14 at different positions in the circumferential direction centered on the photographing optical axis O directed outward of the optical path opening 11. Yes. In addition, from a part on the upper side of the blade presser 2, when the diaphragm frame 3 is fitted, a locking claw portion 15 for hooking and locking a part of the rear surface of the diaphragm frame 3 extends backward. Has been.

  The diaphragm frame 3 has a hole 43 formed in a perfect circle shape with a larger opening diameter than the optical path opening 11 of the blade presser 2 at the center, and is made of metal or plastic colored so as to have a light shielding property. A frame main body 41 is formed by injection injection. A screw hole 42 into which the fixing screw 8 is screwed is formed at two positions on the front surface of the frame body 41. Further, the frame body 41 is fitted into the two defining holes 13 of the blade retainer 2 so that position defining pins 45 for defining the fitting position with the blade retainer 2 are directed forward at two upper and lower positions. Projected.

  The frame main body 41 is formed with an inward flange-like rib 44 on the inner peripheral surface forming the hole 43 so that a predetermined step is formed from the front side to the rear side. Further, the rib 44 has a C-shaped front surface when viewed from the front, and the rib 44 has an inward projection amount in the direction of the photographing optical axis O that does not exceed the optical path opening 11 of the blade retainer 2. Have. The rib 44 has two end surface portions 44 a and 44 b that are orthogonal to the opening surface of the hole portion 43 and are separated by a predetermined distance.

  The frame body 41 is planted or integrally formed so as to protrude forward at different circumferentially spaced positions around the photographing optical axis O toward the outer side of the hole 43. A support pin 46 constituting seven support shafts is provided. The seven spindle pins 46 are inserted into the seven pin fitting holes 14 formed in the blade holder 2 when the blade holder 2 and the diaphragm frame 3 are fitted together.

  The motor 4 disposed in the diaphragm frame 3 is fixed to the rear lower side of the frame body 41. The motor 4 is provided with a spur-like small outer diameter gear 51 and has a terminal connector portion 52 that constitutes an electrical contact with the outside on a side portion. The gear 51 constitutes a pinion that meshes with a rack 33 of the diaphragm plate 7 described later.

  The aperture plate 7 is made of a metal or a resin such as a plastic colored so as to have a light-shielding property. The aperture plate 7 is a disc-shaped rotary ring 31 having a hole 34 formed in the center thereof. A rack plate 32 that is substantially T-shaped when viewed from the front and extends downward from the lower rear portion of the ring 31. The hole 34 of the rotating ring 31 is a perfect circular hole having a hole diameter equal to or larger than the opening diameter of the optical path opening 11 of the blade retainer 2.

  On the front surface of the rotating ring 31, a drive that is planted or integrally formed so as to protrude forward at different circumferentially spaced positions around the photographing optical axis O toward the outer side of the hole 34. Here, there are seven drive pins 35 constituting the shaft.

  The rack plate body 32 has a neck portion 32 a extending downward from the back surface of the rotating ring 31, and the rack 33 is disposed on the outer peripheral edge of the plate body extending from the neck portion 32 a in the left-right direction concentrically with the rotating ring 31. Is formed.

  The diaphragm plate 7 configured as described above is rotatably fitted to the diaphragm frame 3. More specifically, the rotation ring 31 has a perfect circle shape in which the outer diameter is substantially the same as the diameter of the hole 43 formed in the frame body 41 of the diaphragm frame 3, and the plate thickness is the frame body. A thickness dimension substantially the same as a predetermined step from the front surface of 41 to the front surface of the rib 44 is set.

  That is, in a state where the rotating ring 31 is accommodated in the hole 43 of the frame main body 41, the outer peripheral surface of the rotating ring 31 is held by the inner peripheral surface forming the hole 43 of the frame main body 41. Is held by the front surface of the rib 44. The rotation ring 31 is rotatably accommodated in the diaphragm frame 3 so that the front surface is positioned substantially in the same plane as the front surface of the frame body 41. Each drive pin 35 is located on the inner side of the support shaft pin 46 provided on the frame main body 41 toward the photographing optical axis O in a state where the diaphragm plate 7 is accommodated in the diaphragm frame 3.

  Further, the rotation ring 31 is slidably held on the front side by the blade press 2 via the diaphragm blade group 5. Therefore, the rotation ring 31 is prevented from dropping from the hole 43 of the frame main body 41.

  The rack plate 32 is arranged so that a part thereof is in contact with the back side of the frame body 41 of the aperture plate 7, and the rack 33 is engaged with the gear 51 of the motor 4. That is, the gear 51 of the motor 4 and the rack 33 of the aperture plate 7 constitute a rack and pinion, and the rotating ring 31 reciprocally rotates around the optical axis O in the hole 43 by the driving force of the motor 4. Driven.

  The base portion of the neck portion 32 a of the rack plate body 32 of the diaphragm plate 7 is disposed between the end surface portions 44 a and 44 b of the rib 44 of the frame body 41. Thus, one side surface of the base portion of the neck portion 32 a abuts on the end surface portion 44 a of the rib 44 and the other side surface abuts on the end surface portion 44 b of the rib 44, so that the rotation range of the rotation ring 31 of the diaphragm plate 7 is increased. It is prescribed. That is, as for the rotation range of the rotation ring 31 of the diaphragm plate 7, the opening amount of the minimum diaphragm is defined from the full opening of the open diaphragm in the diaphragm device 1 of the present embodiment.

Next, the configuration of the diaphragm blades 6 of the diaphragm blade group 5 will be described in detail.
As described above, the diaphragm blade group 5 is configured such that the seven diaphragm blades 6 are arranged so as to partially overlap each other around the photographing optical axis O.

As shown in FIG. 3, each of these diaphragm blades 6 controls a rotation hole 21 formed at the end of an arm portion 23 extending upward in the drawing and a rotation amount around the rotation hole 21. And a cam groove 22 drilled in a predetermined curved shape along one edge toward the opposite side away from the base of the arm 23.
Each diaphragm blade 6 is rotatably fitted to a predetermined spindle pin 46 of a frame body 41 in which a rotation hole 21 is formed in the diaphragm frame 3, and a rotation ring in which a cam groove 22 is formed in the diaphragm plate 7. It is inserted into 31 predetermined drive pins 35. Each diaphragm blade 6 is sandwiched between the diaphragm frame 3 and the blade holder 2 that are fitted to each other so as to be rotatable around the support pin 46. It should be noted that the hole diameter of the rotation hole 21 and the diameter of the support pin 46, the groove width of the cam groove 22 and the diameter of the drive pin 35 have a predetermined accuracy that does not hinder the rotation or movement of each diaphragm blade 6. The substantially same dimension is set with the clearance fit.

  Further, each diaphragm blade 6 is located on one side portion (on the paper surface of FIG. 3) located on the outer side (the outer peripheral side away from the photographing optical axis O) with respect to the optical path opening 11 of the blade holder 2 through which the photographing optical path passes. The first concave portion 24 formed on the left side), the first convex portion 25 formed to extend outwardly from the concave portion 24 toward the outer side, and the blade press 2 It is formed on the other side (the right side in the drawing of FIG. 3) located on the inner side (the inner circumferential direction close to the photographing optical axis O) with respect to the optical path opening 11, and is set to a predetermined value for forming the aperture opening. A circular arc-shaped aperture forming edge 26, a second convex portion 27 formed so as to extend upward along the aperture forming edge 26 and juxtaposed with the arm portion 23, and the second convex portion And a second concave portion 28 formed between the arm portion 23 and the arm portion 23.

In addition, since each aperture blade 6 has the same shape and has light shielding properties, for example, it forms a light shielding thin plate formed of a resin film coated in black.
As shown in FIG. 4, the first concave portion 24 has an interference between the support pin 46 and the diaphragm blade 6 that rotatably holds the adjacent diaphragm blade 6 in the counterclockwise direction when the open diaphragm is fully opened. Is preventing. Further, the first convex portion 25 covers the cam groove 22 of the adjacent diaphragm blade 6 in the counterclockwise direction that enters the subject luminous flux from the optical path opening 11 of the blade retainer 2 toward the photographing optical axis O. It is for shading. Further, the aperture forming edge 26 is for defining the aperture of the subject luminous flux around the optical axis O together with the aperture blades 6 that are superposed upon entering the subject luminous flux.

  The second convex portion 27 covers and shields the cam groove 22 of the adjacent diaphragm blade 6 in the clockwise direction that enters the subject light beam. Further, the second concave portion 28 prevents interference between the drive pin 35 and the aperture blade 6 that rotationally drives the adjacent aperture blade 6 in the clockwise direction when the open aperture is fully opened.

  Each aperture blade 6 configured as described above enters and exits the optical path opening portion 11 by turning around the support pin 46, thereby defining a predetermined aperture amount (aperture value, aperture amount). To do.

Next, the opening / closing operation | movement of the aperture blade group 5 of the aperture stop apparatus 1 comprised as mentioned above is demonstrated.
As shown in FIG. 5, each diaphragm blade 6 of the diaphragm blade group 5 is configured such that the diaphragm forming edge 26 is the optical path opening 11 of the blade holder 2 (a circle indicated by a two-dot chain line in FIG. 5) when the diaphragm blade is fully opened. ) Slightly outside. At this time, the base portion of the neck portion 32a of the rack plate body 32 of the diaphragm plate 7 contacts the end surface portion 44b of the rib 44 of the frame main body 41, and the rotational movement of the rotating ring 31 in the counterclockwise direction is restricted. It is in the state.

  Further, when the aperture device 1 closes (throttles) the subject light beam to a predetermined opening amount, the gear 51 of the motor 4 rotates counterclockwise. As the gear 51 and the rack 33 of the diaphragm plate 7 mesh with each other, the rack plate body 32 moves to the left, which is a clockwise direction around the photographing optical axis O. Thereby, the rotation ring 31 starts to rotate in the clockwise direction around the photographing optical axis O. The motor 4 is driven and controlled by a control unit (not shown) provided in the camera or the like.

  As shown in FIGS. 6 to 10, each diaphragm blade 6 is a spindle pin with which each rotation hole 21 is fitted as the rotation ring 31 rotates in the clockwise direction around the photographing optical axis O. Rotate counterclockwise around 46 and rotate counterclockwise, and each aperture forming edge 26 closes the subject luminous flux so as to have a predetermined opening amount in a substantially circular shape.

  More specifically, each diaphragm blade 6 has an edge portion of each cam groove 22 into which the drive pin 35 of the rotation ring 31 is fitted, in the clockwise direction around the photographing optical axis O of the rotation ring 31. It is pushed by the drive pin 35 that moves with the rotation. Thereby, each diaphragm blade 6 rotates (turns) counterclockwise around the support shaft pin 46 according to the shape of the cam groove 22 according to the movement of the drive pin 35. That is, as shown in FIG. 6 from the state of FIG. 5, each diaphragm blade 6 turns by controlling the amount of rotation in the counterclockwise direction around the support pin 46 according to the shape of the cam groove 22, It begins to enter into the second optical path opening 11.

  When the rotating ring 31 further rotates clockwise around the photographing optical axis O, each diaphragm blade 6 is in a state where the minimum aperture is shown in FIGS. 7 to 10 (maximum aperture value). The counterclockwise rotation around the center stops.

  As a result, the diaphragm blades 6 enter the subject light flux so as to cover the periphery of the optical path opening 11 of the blade retainer 2 by the respective diaphragm forming edges 26 while overlapping each other so as to overlap each other. Note that the state of the diaphragm blade group 5 in which the respective diaphragm blades 6 turn as shown in FIG. 10 is the minimum diaphragm state in which the subject luminous flux is most narrowed in the diaphragm device 1 of the present embodiment. At this time, the base portion of the neck portion 32a of the rack plate body 32 of the diaphragm plate 7 is in contact with the end surface portion 44a of the rib 44 of the frame body 41, and the rotational movement of the rotating ring 31 in the clockwise direction is restricted. It is in a state.

  Further, when opening the aperture of the subject luminous flux, the motor 4 is rotated in the reverse direction. Then, the rotation ring 31 is rotated counterclockwise about the photographing optical axis O, and the drive pin 35 pushes the edge of the cam groove 22 of each diaphragm blade 6 to thereby follow the shape of the cam groove 22. Each diaphragm blade 6 is controlled to rotate (turn) clockwise about the spindle pin 46.

  Here, a description will be given of a state in which the cam groove 22 of the diaphragm blade 6 is covered and shielded by the adjacent diaphragm blade 6 when changing the aperture opening amount.

  First, in the open aperture shown in FIG. 5, the cam groove 22 of each aperture blade 6 is in a state where it does not enter the subject light beam in the optical path opening 11 of the blade retainer 2. Also, in the predetermined first and second intermediate diaphragms shown in FIGS. 6 and 7, the cam grooves 22 of the diaphragm blades 6 are partially covered by the adjacent diaphragm blades 6. The aperture is not in the light beam of the subject when fully open (inside the optical path opening 11) (see the dashed-dotted line circle A in FIG. 6 and the dashed-dotted line circle B in FIG. 7).

  Next, in the predetermined third and fourth intermediate diaphragms and the minimum diaphragm state shown in FIGS. 8 to 10, the cam groove 22 of each diaphragm blade 6 is in the subject light flux (the optical path opening of the blade holder 2). 11)). Further, as the optical path opening amount (aperture opening amount) is decreased by each diaphragm blade 6, the amount of entry of the cam groove 22 of each diaphragm blade 6 into the subject light beam (in the optical path opening portion 11 of the blade holder 2) increases. .

  In all the states of the predetermined third and fourth intermediate stops and the minimum stop, the cam groove 22 portion of each stop blade 6 entering the subject light beam rotates clockwise about the photographing optical axis O. The light is covered and shielded by two diaphragm blades 6 on both sides adjacent to each other in the direction and in the counterclockwise direction. In other words, a part of the subject light beam that attempts to pass through the cam groove 22 of the diaphragm blade 6 in the subject light beam is blocked by the two diaphragm blades 6 on both sides of the diaphragm blade 6.

  The light shielding state of the cam groove 22 that enters the subject light beam will be described in more detail with reference to FIGS. 11 and 12. In the following description, only the three diaphragm blades 6 are illustrated, and the one located in the middle in the vertical direction is the first diaphragm blade 6a, and the photographing optical axis O is centered with respect to the first diaphragm blade 6a. Next to the first diaphragm blade 6a adjacent to the clockwise direction in FIG. 11 in the plane of the plane of the drawing in FIG. 11 (the back surface of the first diaphragm blade 6a in the optical axis O direction), the second diaphragm The blade 6b is adjacent to the first diaphragm blade 6a in the counterclockwise direction around the photographing optical axis O, and is located below the first diaphragm blade 6a (in the optical axis O direction, the first The front of the first diaphragm blade 6a) is the third diaphragm blade 6c.

  Further, a support pin that rotates and holds the first aperture blade 6a is defined as a first support shaft pin 46a, and a rotation hole of the first aperture blade 6a into which the first support shaft pin 46a is fitted is a first. The rotary shaft 21a and the support pin that rotates and holds the second diaphragm blade 6b are referred to as a second support pin 46b, and the rotation hole of the second stop blade 6b into which the second support pin 46b is fitted. Is the third spindle pin 46c, and the third spindle blade 46c into which the third spindle pin 46c is fitted is the spindle pin that pivotally holds the second rotary hole 21b and the third diaphragm blade 6c. The rotation hole 6c is indicated by a third rotation hole 21c. The first support shaft pin 46a is located between the second support shaft pin 46b and the third support shaft pin 46c in the circumferential direction centered on the photographing optical axis O.

  Furthermore, the drive shaft provided in the rotation ring 31 of the diaphragm plate 7 for controlling the rotation of the first diaphragm blade 6a is a first drive pin 35a, and the first diaphragm into which the first drive pin 35a is fitted. A first cam groove of the blade 6a is denoted by reference numeral 22a. Similarly, the second cam groove of the second diaphragm blade 6b that is rotationally controlled by the second drive pin 35b is denoted by reference numeral 22b, and the third diaphragm blade 6b that is rotationally controlled by the third drive pin 35c. The third cam groove is denoted by reference numeral 22c.

  The first convex portion of the second diaphragm blade 6b that covers and shields the first cam groove 22a of the first diaphragm blade 6a is denoted by reference numeral 25b, and the cam groove of the first diaphragm blade 6a is shown. The second convex portion of the third diaphragm blade 6c that covers and shields the light is denoted by reference numeral 27c.

  As shown in FIG. 11, the portion of the first diaphragm blade 6a that enters the optical path opening 11 of the blade retainer 2 of the first cam groove 22a is the first convex portion 25b of the second diaphragm blade 6b. , And the second convex portion 27c of the third diaphragm blade 6c is covered and shielded by the overlap in the front and rear direction of the optical axis O direction.

  More specifically, as shown in FIG. 12 in which the XII region shown in FIG. 11 is enlarged, a part of the first diaphragm blade 6a entering the optical path opening 11 of the first cam groove 22a is part of the photographing optical axis. It is covered by the first convex portion 25b of the second diaphragm blade 6b that is positioned adjacent to and overlaps in the clockwise direction with O as the center (light shielding region B indicated by a horizontal stripe line in the figure). In addition, a part of the first diaphragm blade 6a that enters the optical path opening 11 of the first cam groove 22a is positioned adjacent to and overlaps with the photographing optical axis O as a center. It is covered by the second convex part 27c of the third diaphragm blade 6c (light shielding region C indicated by vertical stripes in the figure).

  That is, the unshielded remaining portion (unshielded remaining portion) of the first cam groove 22a of the first diaphragm blade 6a that cannot be shielded by the first convex portion 25b of the second diaphragm blade 6b is replaced with the third diaphragm blade 6c. The second convex portion 27c is shielded from light. Then, in the portion where the first cam groove 22a of the first aperture blade 6a enters the subject light beam, the first convex portion 25b of the second aperture blade 6b and the third aperture blade 6c A region where the second convex portion 27c overlaps and shields light is indicated by a light shielding region BC (lattice state in FIG. 2). That is, the unshielded remaining portion of the first cam groove 22a of the first diaphragm blade 6a that cannot be shielded by the first convex portion 25b of the second diaphragm blade 6b is the light shielding region C and outside the light shielding region BC. It is an area. Further, since the second diaphragm blade 6b and the third diaphragm blade 6c are sequentially laminated in the direction of the optical axis O via the cam groove 22a of the first diaphragm blade 6a having a thickness corresponding to the plate thickness, the optical axis O A space is formed in the cam groove 22a in a direction orthogonal to the direction of the angle. Specifically, the space is formed in the light shielding region C from the light shielding region B via the light shielding region BC. However, since the periphery of the light-shielding region C is shielded with a sufficient area and each of the diaphragm blades 6b and 6c is black-treated, light slightly enters the cam groove 22a and leaks into the subject light flux. There is no.

  In the above description, the three first to third diaphragm blades 6a, 6b, and 6c have been described as examples. However, the diaphragm device 1 according to the present embodiment has each diaphragm blade 6 arranged in a circumferential shape. Similarly, the optical path of the blade presser 2 by two diaphragm blades 6 adjacent to each other in the clockwise direction around the photographing optical axis O and the counterclockwise direction with respect to one diaphragm blade 6 as a reference. The cam groove 22 entering the opening 11 is shielded from light.

  From the above description, the diaphragm device 1 according to the present embodiment relates to the cam groove 22 of one diaphragm blade 6 that has entered the optical path opening 11 by forming the second convex portion 27 on each diaphragm blade 6. It can be seen that the non-light-shielding remaining portion that cannot be shielded by other diaphragm blades 6 is covered with the second convex portion to shield light. In addition, each 2nd convex part 27 formed in each aperture blade 6 is not caught in the cam groove 22 of other aperture blades 6 etc. at the time of rotation around the spindle pin 46 of each aperture blade 6, Furthermore, a convex shape that extends in a predetermined manner so as not to interfere with the drive pin 35 of the rotating ring 31 and the like is set.

  Therefore, even if each diaphragm blade 6 is reduced in size by reducing the area, the cam groove 22 formed in each diaphragm blade 6 can be formed to the position where it enters the subject light beam, and the length of the cam groove 22 can be reduced. It can be secured sufficiently. As a result, each support pin 46 provided in the circumferential direction to be fitted and rotated and held in the rotation hole 21 of each diaphragm blade 6 and the cam groove 22 of each diaphragm blade 6 are inserted into the cam groove 22 in the circumferential direction to control the pushing. Since the drive pin 35 to be provided can be disposed close to the inner side of the photographing optical axis O, the shape of the diaphragm frame 3 and the diaphragm plate 7 around the photographing optical axis O can be reduced in size. Therefore, the diaphragm device 1 of the present embodiment can be downsized.

  The invention described in each of the above-described embodiments is not limited to the embodiments and modifications, and various modifications can be made without departing from the scope of the invention in the implementation stage. is there.

  The diaphragm device according to the present invention can be used for a small lens barrel or a camera.

DESCRIPTION OF SYMBOLS 1 ... Diaphragm 2 ... Blade holding | suppressing (opening member)
3 ... Aperture frame (rotating member)
DESCRIPTION OF SYMBOLS 4 ... Motor 5 ... Diaphragm blade unit 6 ... Diaphragm blade 6a ... 1st aperture blade 6b ... 2nd aperture blade 6c ... 3rd aperture blade 7 ... Diaphragm plate (drive member)
11 ... Opening (open aperture fully open)
21 ... Rotating hole 21a ... 1st rotating hole 21b ... 2nd rotating hole 21c ... 3rd rotating hole 22 ... Cam groove 22a ... 1st cam groove 22b ... 2nd cam groove 22c ... 3rd cam groove 23 ... Arm 24 ... First concave portion 25, 25b ... First convex portion 26 ... Drawing forming edge 27, 27c ... Second convex portion 28 ... Second concave portion 31 ... Rotating ring 33 ... Rack 35 ... drive pin 35 ... first drive pin (first drive shaft)
35 ... second drive pin (second drive shaft)
35 ... Third drive pin (third drive shaft)
41 ... Frame body 44 ... Rib O ... Shooting optical axis

Claims (2)

In a diaphragm device having a plurality of diaphragm blades overlapping each other,
An opening member having an opening and centered on the optical axis of the photographing optical system,
A first support shaft provided outside the opening;
A second support shaft provided at a circumferential position around the optical axis different from the first support shaft outside the opening;
A circumferential position around the optical axis different from the first support shaft and the second support shaft outside the opening so as to sandwich the first support shaft together with the second support shaft A third support shaft provided in
A first drive shaft disposed on the optical axis in the direction from the first support shaft, and a second drive shaft disposed on the optical axis in the direction from the second support shaft, anda third drive shaft disposed on the optical axis in the direction from the third support shaft, said first drive shaft, said second drive shaft, and the third drive shaft A drive member that reciprocates around the optical axis;
One of the diaphragm blades, a first rotation hole that is rotatably fitted to the first support shaft, and the first drive shaft are fitted, and the drive member is driven. And a first cam groove capable of controlling the amount of rotation about the first support shaft in accordance with the amount of movement of the first drive shaft about the optical axis and entering the subject luminous flux. A first diaphragm blade that enters the subject luminous flux in accordance with the rotation around the first support shaft controlled by the first cam groove;
One of the diaphragm blades different from the first diaphragm blade, the second rotation hole that is rotatably fitted to the second support shaft, and the second drive shaft are fitted, When the drive member is driven, the amount of rotation of the second drive shaft about the optical axis is controlled in accordance with the amount of movement of the second drive shaft about the optical axis, and the second light can enter the subject luminous flux . Two cam grooves, and as the first diaphragm blades enter the subject luminous flux as the second cam groove rotates around the second support shaft, a second diaphragm blade for shielding a part in the subject light flux of the first cam groove,
The first diaphragm blade and one of the diaphragm blades different from the second diaphragm blade, wherein the third rotation hole is rotatably fitted to the third support shaft; The second drive shaft is inserted and the drive member is driven to control the amount of rotation of the third drive shaft around the optical axis according to the amount of movement of the third drive shaft around the optical axis , A third cam groove capable of entering into the subject luminous flux, and the first diaphragm blade cannot be shielded by the second diaphragm blade as the first diaphragm blade enters the subject luminous flux. a third diaphragm blade for shielding the remaining non-shielding balance in the subject light flux of the cam groove,
A diaphragm device characterized by comprising: It said portion to shield the non-light shielding remainder of the third diaphragm blades, the diaphragm device according to claim 1, characterized in that it is formed to extend in a convex shape.

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