JP2009008853A - Light quantity adjusting device, lens device and camera system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a light quantity adjusting device maintaining optical performance and improving the degree of freedom in terms of optical design. <P>SOLUTION: The light quantity adjusting device includes: a rotating member; a driving part for driving the rotating member; a plurality of diaphragm blades arranged to be superposed on each other so as to form an aperture part and engaged with the rotating member; and a cam member for actuating the plurality of diaphragm blades so that the aperture part may be set to a predetermined opening by the rotation of the rotating member. An abutting part is formed on the diaphragm blade, and also a slope part abutting on the abutting part is formed on the cam member or the rotating member, and the abutting part moves along the slope part with the actuation of the diaphragm blade. The slope part is formed so that the pushing-up of the aperture part of the diaphragm blade in the optical axis direction may be smaller by pressing the abutting part in an opposite direction to the optical system in an optical axis direction as the plurality of diaphragm blades are actuated from an open side to a small diaphragm side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light amount adjusting device used in an optical system.

  As a conventional light amount adjusting device, Patent Document 1 discloses a plurality of diaphragm blades formed with a driving rod and a rotating rod by injection molding on a resin material such as a polyester sheet or a metal material such as a stainless steel sheet on the periphery of the lens frame. A diaphragm aperture is formed by overlapping the apertures. Then, the long hole formed in the diaphragm driving plate is engaged with the driving rod, and the diaphragm driving plate is driven, so that each diaphragm blade opens and closes the diaphragm opening around the rotating rod.

Further, in Patent Document 2, when a blade substrate is injection-molded, a driving dowel and a rotating dowel are integrally formed, and a plurality of diaphragm blades formed in this way are arranged around the blade chamber to thereby form a diaphragm opening. Is forming.
Japanese Patent No. 2707622 Japanese Patent Laid-Open No. 06-317826

  In the conventional light amount adjustment device, a plurality of aperture blades are arranged on the circumference to form an aperture opening, so that the aperture blade is relatively close to the open side than the open side on the small aperture side. It is known that a phenomenon in which the vicinity of the opening rises (swells in the direction of the optical axis) occurs. This phenomenon causes the diaphragm blades to come into contact with an optical system such as a lens adjacent to the surface to damage the surface coating and deteriorate the optical performance. In addition, in the past, in view of the amount of squeezing of the diaphragm blades, the optical system close to the diaphragm blades must be arranged apart along the optical axis direction, which is a factor that reduces the degree of freedom in optical design. ing.

  The present invention has been made in view of the above problems, and an object of the present invention is to realize a light amount adjusting device capable of maintaining optical performance and improving the degree of freedom in optical design.

  In order to solve the above-described problems and achieve the object, the light amount adjusting device of the present invention is arranged to overlap each other so as to form a rotating member, a driving unit that drives the rotating member, and an opening. In a light quantity adjusting device comprising: a plurality of diaphragm blades that engage with a rotating member; and a cam member that operates the plurality of diaphragm blades so that the opening has a predetermined opening degree by rotation of the rotating member. And forming a contact portion on the diaphragm blade, and forming a slope portion in contact with the contact portion on the cam member or the rotating member, and the contact portion becomes the slope portion as the diaphragm blade operates. As the plurality of diaphragm blades move from the open side to the small diaphragm side, the contact portion is pressed in the direction opposite to the optical system along the optical axis direction, and the aperture of the diaphragm blades The upsurge in the optical axis direction is small The formation of the inclined surface portion so Kunar.

  The lens device of the present invention includes a diaphragm device having the light amount adjusting device, an optical system having a plurality of lenses, and a control unit that controls the diaphragm device and the optical system.

  The camera system of the present invention includes the lens device and a camera device to which the lens device is detachable.

  According to the present invention, it is possible to suppress the squeezing phenomenon that occurs when the diaphragm blades operate toward the small diaphragm side, and therefore it is possible to suppress the diaphragm blades from contacting the optical system and degrading the optical performance.

  In addition, since an optical design that anticipates the amount of squeezing of the diaphragm blades is not required, the degree of freedom in optical design can be increased and an optical system having good optical performance can be realized.

  Hereinafter, an embodiment according to the present invention will be described in detail with reference to the drawings.

  The embodiment described below is an example for realizing the present invention, and should be appropriately modified or changed according to the configuration and various conditions of the apparatus to which the present invention is applied. It is not limited to the embodiment.

[Camera system]
First, a camera system equipped with a lens device to which the light amount adjusting device of the present invention is applied will be described.

  FIG. 13 is a block diagram showing a camera system to which a lens device to which the light amount adjusting device of the present invention is applied is mounted.

  In FIG. 13, reference numeral 200 denotes a camera body, and 300 denotes an interchangeable lens body that is detachable from the camera body 200. The interchangeable lens body 300 is attached to the camera body 200, and an interchangeable lens lens autofocus (AF) single-lens reflex camera is installed. It is composed.

  Reference numeral 201 denotes a camera control unit constituted by a microcomputer, which controls operations of various devices mounted on a camera body 200 described later. Further, the camera control unit 201 communicates with the lens control unit 301 by connecting the lens contact 302 and the camera contact 202 with the lens body 300 mounted.

  Reference numeral 203 denotes a power SW that can be operated by the user, and is a switch that activates the camera control unit 201 to supply power to each actuator, sensor, and the like of the camera main body 200 so as to be operable.

  Reference numeral 204 denotes a two-stage stroke release SW that can be operated by the user, and its signal is input to the camera control unit 201. The camera control unit 201 performs the following photographing operation according to the signal input from the release SW 204.

  That is, when the first stroke SW is turned on and the SW1 signal is output, the exposure lens calculation by the photometry device 205, the distance measurement calculation of the subject by the distance measurement device 208, and the focus lens by the focusing device 306 based on the distance measurement result. The camera shifts to a shooting preparation state such as a focusing operation or focusing determination.

  When the second stroke SW is turned on and the SW2 signal is output, a driving command for a diaphragm device 307, which will be described later, is output to the lens control unit 301 of the lens body 300. The lens control unit 301 controls operations of various devices of the lens main body 300 described later, and the lens contact 302 and the camera contact 202 are connected in a state where the lens control unit 301 is attached to the camera main unit 200. Communicate between the two.

  The lens control unit 301 drives the aperture device 307, and the camera control unit 201 outputs an exposure start command to the exposure device 206 to actually execute the exposure operation. When an exposure end signal is received from the exposure device 206, the camera control unit 201 stores it in the storage device 207. A recording start command is output and the captured image is stored.

  A display device 209 displays various shooting conditions such as an aperture value and a shutter speed, the number of shots, the remaining battery level, and various modes based on a display control command from the camera control unit 201.

  Reference numeral 306 denotes a focusing device, which includes a focus lens and its holding member, a lens driving unit for driving the focus lens to a target position, and a transmission mechanism for transmitting the driving force of the lens driving unit to the focus lens. Further, the focusing device 306 includes a lens driving circuit that is controlled by the lens control unit 301 in accordance with the movement amount information of the focus lens output from the camera control unit 201 and outputs a driving command to the lens driving unit.

  Reference numeral 307 denotes a diaphragm device, a diaphragm mechanism for setting a diaphragm aperture area to a predetermined opening, a diaphragm driving unit for driving the diaphragm mechanism, and a lens control unit according to a diaphragm operation command from the camera control unit 201. 301 is controlled. The aperture device 307 includes an aperture drive circuit that outputs a drive command to the aperture drive unit.

  The light quantity adjusting device of the present invention is a concept including the aperture mechanism and the aperture drive unit of the aperture device.

[Light control device]
FIG. 1 is an exploded view of a diaphragm device according to an embodiment to which the light amount adjusting device of the present invention is applied. FIG. 2 is a perspective view of the diaphragm blade of FIG. FIG. 3 is a front view of the diaphragm blade of FIG. FIG. 4 is a perspective view of the cam plate of FIG. FIG. 5 is a front view showing the positional relationship between the diaphragm blades and the cam plate of FIG.

  In FIG. 1, reference numeral 1 denotes a cover member formed of an elastic material such as a synthetic resin, and covers a rotor unit as an aperture drive unit described later. The cover member 1 has a bearing 1a that pivotally supports a rotating shaft 4 to be described later, and holes 1b-1 to 1b-4 through which terminals of a bobbin 5 to be described later are inserted. Further, the cover member 1 includes a protruding piece 1c that suppresses a later-described position detection element 12 from being pulled out, holes 1c-1 to 1c-3 that are formed on the protruding piece 1c and through which the terminal portion 12a of the position detection element 12 is inserted, and positions. A projection 1j (FIG. 14) that contacts the end face of the detection element 12 is provided. Further, the cover member 1 is formed with a locking claw at the tip so as to snap-fit to a seat 1d fastened to a case member 13 described later and an insertion hole 1d-1 formed in the seat 1d. It has an elastic piece 1k (FIG. 14). Furthermore, the cover member 1 has a thin piece portion 1f (FIG. 14) that bridges the seat portion 1d and a storage portion that stores a drive member to be described later, and a fitting piece portion for positioning by fitting with the case member 13. 1e-1 and 1e-2 (FIG. 14). Moreover, the cover member 1 has fitting parts 1g-1, 1g-2, 1h-1 to 1h-4 (FIG. 14) for fitting and positioning a yoke member 9 described later.

  Reference numeral 2 denotes a rotor formed of a permanent magnet, 3 denotes a disk-shaped core for fixing the rotor 2 by adhesion or the like, and 4 denotes a rotating shaft for fixing the core 3 by press-fitting or the like. Reference numerals 5a and 5b are bobbins formed of synthetic resin or the like, which have terminal portions for feeding power, and coils 6a and 6b are attached, and lead wires of the coils are connected to the terminal portions, so that plating is performed by soldering. Is given.

  7 is a washer that is formed of a material having high lubricity and reduces sliding friction between the end surface portion of the core 3 and an end surface portion of the bearing 10 described later. 8 is a sheet member that is formed of an insulating sheet material and is disposed between coils 6a and 6b and a yoke 9 to be described later so that they do not conduct, and a clearance hole portion 8a of a bearing 10 to be described later. And escape holes 8b-1 and 8b-2 of the yoke 9 described later are formed.

  Reference numeral 9 denotes a yoke formed of a soft magnetic material, stator portions 9b-1 and 9b-2 bent so as to face the rotor 2, holes 9a for fixing a bearing 10 described later by press-fitting or the like, a cover It has fitting surface portions 9c-1 to 9c-6 for fitting with the member 1. The bearing 10 is made of a magnetic material and has a bearing hole 10a and a flange portion 10b with which the rotary shaft 4 is engaged.

  Reference numeral 11 denotes a pinion, which has a hole portion 11a for being fixed to the tip end of the rotating shaft 4 by press-fitting or the like, and a gear portion 11b for transmitting the rotational force of the driving portion to a rotary plate 14 described later. Reference numeral 12 denotes a position detecting element such as a photo interrupter for detecting a rotational position of a rotary plate 14 described later, and has a terminal portion 12a.

  Reference numeral 13 denotes a case member made of synthetic resin or the like, and has a protruding portion 13a protruding in the optical axis direction. The protruding portion 13 a is formed with a receiving surface portion 13 a-3 that contacts the back surface of the seat portion 1 d of the cover member 1. Further, the protrusion 13a has a fitting protrusion 13a-2 that fits into the fitting end surface portions 1e-1-a and 1e-2-a (FIG. 14) of the fitting pieces 1e-1 and 1e-2. Is formed. Moreover, the hole 13a-1 which fastens the fastening member 17 is formed in the protrusion part 13a.

  Further, the case member 13 is formed with a hole portion 13b through which the pinion 11 is inserted, a hole portion 13c into which the flange portion 10b of the bearing 10 is fitted, and a seat surface portion 13d that contacts the end surface portion of the yoke 9. Further, the case member is formed with a storage portion 13e for storing the position detection element 12 and a relief hole 13g of a shielding plate portion 14a of the rotary plate 14 described later. Further, the case member 13 has locking holes 13h-1 to 13h in which the insertion holes 13f of the elastic piece 1k (FIG. 14) and locking claws 16b-1 to 16b-3 of the cam plate 16 described later are engaged. -3 is formed. Further, the case member 13 is formed with holes and grooves 13i-1 and 13i-2 that engage with the positioning shafts 16a-1 and 16a-2. Further, the case member 13 is formed with a hole portion 13j in which rib portions 14b-1 to 14b-6 of a rotary plate 14 described later are engaged.

  Reference numeral 14 denotes a rotary plate formed of a synthetic resin or the like as a rotating member. The rotary plate 14 engages with a shielding plate portion 14a and a hole portion 13j that shields projection light from the position detection element 12, and rotates the rotary plate 14 about the optical axis. Ribs 14b-1 to 14b-6 are provided. The rotary plate 14 has a gear portion 14 c that meshes with the gear portion 11 b of the pinion 11 and transmits a rotational force to the rotary plate 14. Further, the rotary plate 14 has a hole 14d-1 for engaging shafts 15a-1, 15b-1, 15c-1, 15d-1, 15e-1, 15f-1 of a diaphragm blade 15 described later. -14d-6 is formed. Further, the rotary plate 14 has projections 14e-1 to 14e-3 (14e-3 not shown) for contacting the end surface portion of the case member 13 in the optical axis direction to position the plate 14 in the optical axis direction. The three protrusions are arranged approximately equally around the optical axis). 14f is an opening diameter.

  Reference numerals 15a to 15f are diaphragm blades formed of a synthetic resin or a metal thin plate or the like, and shaft portions 15a-1, 15b-1, 15c-1, and 15d-1 that engage with the hole portions 14d-1 to 14d-6. , 15e-1, 15f-1. Further, the diaphragm blade 15 has shaft portions 15a-2, 15b-2, 15c-2, 15d-2, 15e-2, 15f-2 (15b) which engage with cam holes 16c to 16h of the cam plate 16 which will be described later. -2, 15c-2, and 15d-2 are not shown).

  2 and 3 are enlarged views of the diaphragm blade of FIG. A protrusion 15a-3 is formed on one surface of the aperture blade 15a. This protrusion 15a-3 is formed integrally with the diaphragm blade 15a by injection molding. This protrusion 15a-3 is similarly formed on the other diaphragm blades 15b to 15f (15a-3 to 15f-3 in FIG. 5).

  Reference numeral 16 denotes a cam plate as a cam member, which has cam holes 16c to 16h. The cam plate 16 includes shaft portions 16 a-1 and 16 a-2 for positioning with the case member 13, and locking claws 16 b-1 to 16 b-for snap-fit coupling the cam plate 16 to the case member 13. 3. It has an opening hole 16k. Reference numerals 16p to 16u denote inclined surface portions provided between the cam holes 16c to 16h and the outer periphery of the opening hole portion 16k, and abut against the projections 15a-3 to 15f-3 of the diaphragm blades 15a to 15f. These inclined surface portions 16p to 16u have inclined surfaces that gradually increase in height as the diaphragm blades 15a to 15f move to the small aperture side. FIG. 5 shows a state in which the aperture blades 15a to 15f are on the small aperture side. On the small aperture side, the protrusions 15a-3 to 15f-3 are at positions where the heights of the inclined surface portions 16p to 16u are high.

  Next, the mutual relationship between the components will be described in accordance with the assembly procedure.

  First, the bearing 10 is attached to the yoke 9. The outer shape of the bearing 10 is fixed to the hole 9a of the yoke 9 by press fitting or the like. At that time, the flange portion 10b of the bearing 10 abuts against the end surface portion of the yoke 9, and the position of the bearing 10 with respect to the yoke 9 is determined.

  Next, the sheet member 8 is laid on the yoke 9. At that time, the holes 8b-1 and 8b-2 are inserted through the stator portions 9b-1 and 9b-2 of the yoke 9.

  Next, the hollow portions (not shown) of the bobbins 5a and 5b to which the coils 6a and 6b are attached are inserted through the stator portions 9b-1 and 9b-2 of the yoke 9.

  Next, the washer 7 is inserted into the rotating shaft 4 of the rotor unit in which the rotor 2 and the rotating shaft 4 are integrated, and the end of the rotating shaft 4 is engaged with the hole 10 a of the bearing 10.

  Next, the yoke 9 is attached to the cover member 1. At that time, the fitting surface portions 9c-1 to 9c-6 of the yoke 9 are fitted to the fitting portions 1h-1 to 1h-4, 1g-1, and 1g-2, respectively. At this time, when a part of the fitting portion, for example, 9c-5, 9c-6 and 1g-1, 1g-2 is press-fitted, the yoke 9 is fixed to the cover member 1 and is inadvertently disassembled during assembly. Will not be lost. FIG. 5 shows the state after the assembly described above.

  Next, the pinion 11 is fixed to the tip of the rotating shaft 4 by press fitting or the like.

  Next, the cover member 1 is attached to the case member 13.

  As shown in FIG. 15, the cover member 1 attached to the pinion 11 is moved to the case member 13 in the optical axis direction. At that time, the position detecting element 12 is housed in the housing portion 13 e of the case member 13. Further, the cover member 1 is moved closer to the case member 13, and the fitting surface portions 1e-1-a and 1e-2-a (FIG. 14) are fitted to the protruding portions 13a-2 (FIG. 1), respectively. Further, the flange portion 10 b of the bearing 10 is fitted into the hole portion 13 c of the case member 13. The cover member 1 is positioned on the case member 13 by these fittings. Simultaneously with these fittings, the terminal portion 12a is inserted into the holes 1c-1 to 1c-3. When the cover member 1 is further moved closer to the case member 13, the end surface portion of the seat portion 1d comes into contact with the receiving surface portion 13a-3. The receiving surface portion 13a-3 is an inclined surface. As shown in FIG. 15, there is a difference in height of T in the line direction connecting the center of the hole portion 13a-1 and the center of the hole portion 13c. Is lower.

  When the cover member 1 is fastened to the case member 13 by the fastening member 17, the thin piece portion 1f is elastically deformed so that the end surface portion of the seat portion 1d follows the receiving surface portion 13a-3 having a height difference. Since the height difference T is lower on the hole 13c side, this elastic deformation generates a force that abuts the end surface portion 9e of the yoke member 9 against the seat surface portion 13d. Thereby, the position of the yoke member 9 and the case member 13 in the optical axis direction is determined, the position of the pinion 11 is arranged at an appropriate position, and the gear portion 11b and the gear portion 14c of the rotary plate 14 can maintain good meshing. Therefore, an accurate aperture diameter is realized by the diaphragm blades. The protrusion 1d-2 provided on the seat surface portion 13d is pressed against the end surface portion of the fastening member 17 in a state where the fastening member 17 is tightened, so that the end surface portion of the seat portion 1d is received by the surface portion 13a-. No. 3 is provided near the thin piece 1f.

  On the other hand, in the state where the cover member 1 is attached to the case member 13, as shown in FIG. 17, the slope portion 1 k-1 of the locking claw portion and the locking claw portion 13 k formed on the case member 13 are in contact. Here, the position of the slope portion 1k-1 is set so that the elastic piece portion 1k has a slight amount of bending. For this reason, the cover member 1 is held by the case member 13 while maintaining the contact force (biasing force) of the end surface portion 9e (FIG. 15) of the yoke member 9 to the seat surface portion 13d. Further, in this state, as shown in FIG. 17, the projection 1j abuts on the end surface 12b of the position detection element 12, and the protruding piece 1c has a slight amount of deflection, and presses and holds the position detection element 12. ing.

Here, as shown in FIGS. 16 and 17, the position of the thin piece portion 1f that is elastically deformed is P, the position that the end surface portion 9e of the yoke member 9 is pressed against the seat surface portion 13d is Q, and the slope portion of the elastic piece portion 1k. The position received by 1k-1 is R, and the position received by the projection 1j of the protruding piece 1c is S. Further, the vertical component force with respect to the line segment PQ of the force f11 at which the yoke member 9 presses the seat surface portion 13d at the point Q is defined as f11a. The vertical component force of the force f12 received by the cover member 1 at the point R with respect to the line segment PR is f12a, and the vertical component force of the force f13 received by the cover member 1 at the point S with respect to the line segment PS is f13a. Furthermore, if the length of the line segment PQ is L1, the length of the line segment PR is L2, and the length of the line segment PS is L3,
f11a · L1 + f12a · L2> f13a · L3
It has become a relationship.

  If at least the above relationship is satisfied, the cover member 1 is lifted from the case member 13 against the force received by the protruding portion 1j of the projecting piece 1c (the contact force of the end surface portion 9e against the seat surface portion 13d is not obtained). A decrease in aperture accuracy due to poor meshing can be avoided.

  According to the above configuration, since the position detection element 12 can be accurately fixed to the shielding plate portion 14a of the rotary plate 14 by the urging force of the cover member 1, fluctuations in detection timing due to mechanical displacement of the position detection element 12 are avoided. can do. In addition, since the position detection element 12 is suppressed by the cover member 1 and can be incorporated from the optical axis direction without rotating the drive unit, a member for stabilizing the installation of the position detection element 12 is not necessary.

Moreover, in the said structure, although the elastic piece part 1k was formed in the cover member 1,
f11a · L1> f13a · L3
If the above relationship is satisfied, the elastic piece 1k may be omitted.

  Further, the inclined surface portion 13a-3 does not need to be an inclined surface. For example, the projection provided on the receiving surface portion 13a-3 and the end surface portion of the seat portion 1d abut against each other with a pressing force to elastically deform the thin piece portion 1f, and the end surface portion 9e of the yoke member 9 becomes the seat surface portion 13d. You may comprise so that it may bias. Moreover, you may provide the said projection part in the end surface part 1d side instead of the receiving surface part 13a-3 side.

  Further, the contact between the end surface portion 9e of the yoke 9 and the seat surface portion 13d of the base member 13 may be contact by a plurality of protrusions. Further, when the cover member 1 and the yoke 9 are press-fitted, since the yoke 9 is fixed to the cover member 1, the contact portion with the seat surface portion 13d is not the end surface portion 9e of the yoke 9 but a part of the cover member 1. There may be.

[Push-up phenomenon and countermeasures]
In the light quantity adjusting device described above, the plurality of aperture blades 15a to 1f are arranged so as to be in sliding contact with each other. That is, the diaphragm blades 15b are stacked on the diaphragm blades 15a, and the diaphragm blades 15c are stacked on the diaphragm blades 15b in order. The last diaphragm blade 15f is disposed below the diaphragm blade 15a. When the diaphragm blades 15a to 1f assembled in this way are actuated to the small diaphragm side, the diaphragm blades disposed below push up the diaphragm blades disposed thereon, so that the openings formed by all the diaphragm blades The phenomenon that the neighborhood rushes up occurs. This rushing phenomenon will be described with reference to FIGS.

  FIG. 6 shows a state of the three diaphragm blades 15a to 15c in the vicinity of the opening at the open position. X indicates the optical axis direction. In the drawing, the upper side is the cam plate side, and the lower side is the rotary plate side. Since the aperture blade 15b is disposed below the aperture blade 15a and above the aperture blade 15c, the aperture blade 15b is inclined obliquely as shown in FIG. In this state, the vicinity of the base of the diaphragm blade 15b (left end in the figure) is bent, and therefore a force f1 for pushing up the diaphragm blade 15a at the contact portion α with the diaphragm blade 15a (the component force in the optical axis direction is f1 ′). ) Acts. Since the force corresponding to the component force f1 'acts on the other diaphragm blades in the same manner, the vicinity of the aperture of the diaphragm blades rises upward in the drawing. Here, since FIG. 6 is in the open state, the component force f1 'is small, and the amount of swell is small compared to the small aperture state.

  On the other hand, in the small aperture state of FIG. 7, the vicinity of the root of the aperture blade 15b (the left end in the drawing) is more greatly bent than in the open state, and therefore the aperture blade 15a is in contact with the aperture blade 15a. A force f2 (the component force in the optical axis direction is f2 ′) is applied. Here, since f2 '> f1', the rising amount is larger than that in the open state. Therefore, the more the operation is performed from the open state to the small-aperture state in FIG.

  Here, in this embodiment, in order to suppress the above-mentioned phenomenon, the protrusion provided on the diaphragm blade is in contact with the inclined surface provided on the cam plate. This configuration will be described with reference to FIG.

  FIG. 8 shows a state in which one aperture blade 15a is operated to the small aperture side. The shaft portion 15a-1 of the aperture blade 15a is engaged with the hole portion 14d-6 of the rotary plate 14. Since the protrusion 15a-3 provided on the aperture blade 15a is in contact with the inclined surface portion 16p at a high position, the play (gap) between the hole portion 14d-6 and the shaft portion 15a-1 and the aperture blade Due to the slight deflection of 15a, the diaphragm blade 15a is inclined upward in the figure. Here, the inclination direction in the vicinity of the aperture of the aperture blade is on the side of the rotary plate 14 in the direction opposite to the direction in which the above-described phenomenon occurs. As described above, along with the operation of the diaphragm blade 15a, the projection 15a-3 moves along the inclined surface portion 16p while being in contact with the inclined surface portion 16p. As a result, the diaphragm blade 15a is tilted in the direction opposite to the direction in which the uplift phenomenon occurs, so that the rise in the optical axis direction near the opening of the diaphragm blade can be reduced.

[Modification]
In the configuration shown in FIG. 8, the inclined surface portion 16 p is provided on the cam plate 16, but the rotary plate 14 may be provided with an inclined surface portion.

  Therefore, a configuration in which an inclined surface portion is provided on the rotary plate will be described below with reference to FIGS. 9 to 12.

  9 to 11 show a rotary plate 314 provided with one diaphragm blade 315c and an inclined surface portion 314p.

  The rotary plate 314 is provided with holes 314d-1 to 314d-6 with which the shaft portion 315c-1 of the aperture blade 315c is engaged. In addition, recesses 314q-1 to 314q-6 are formed in the holes 314d-1 to 314d-6, and the protruding piece 315g-1 of the diaphragm blade 315c (also provided to the other diaphragm blades in the same manner). Has a size that can be inserted. Inclined surface portions 314p-1 to 314p-6 are formed around the hole portions 314d-1 to 314d-6 of the rotary plate 314. Here, the assembly procedure of the aperture blade 315c will be described. The shaft piece 315c-1 is inserted into the hole 314d-2 with the protruding piece 315g-1 aligned with the recess 314q-2. In this state, as shown in FIG. 10, the aperture blade 315c is in a position rotated in the opening direction from the actual opening position. Next, as shown in FIG. 11, the protruding piece portion 315g-1 is aligned with the concave portion 314q-2, the shaft portion 315c-1 is inserted into the hole portion 314d-2, and the aperture blade 315c is rotated to the small aperture side. Then, a protrusion (315h-1 in FIG. 12 described later) provided on the protruding piece 315g-1 comes into contact with the inclined surface 314p-2.

  FIG. 12 shows a state where the shaft portion 315c-1 of the aperture blade 315c is engaged with the hole portion 314d-2 and the projection portion 315h-1 is in contact with the inclined surface portion 314p-2. 18 is an enlarged view of the engaging portion in FIG. In FIG. 18, the inclined surface portion 314 p-2 has a higher inclined surface height as the diaphragm blade 315 c operates from the open side to the small diaphragm side. For this reason, the protrusion 315h-1 is pressed by the inclined surface portion 314p-2, and the aperture blade 315c is inclined upward in the drawing within the range of play between the shaft portion 315c-1 and the hole portion 314d-2. Here, the inclination direction in the vicinity of the aperture of the diaphragm blade is on the rotary plate 314 side opposite to the direction in which the above-described rush phenomenon occurs. Thus, with the operation of the diaphragm blade 315c, the protrusion 315h-1 moves along the inclined surface portion 314p-2 while being in contact with the inclined surface portion 314p-2. Thereby, the swell in the optical axis direction near the opening of the diaphragm blade can be reduced by inclining the diaphragm blade 315c in a direction opposite to the direction in which the phenomenon of the close-up occurs.

  As described above, according to the present embodiment, it is possible to suppress the squeezing phenomenon that occurs when the diaphragm blades are narrowed down, and therefore it is possible to suppress the diaphragm blades from contacting the optical system and degrading the optical performance. .

  In addition, since an optical design that anticipates the amount of squeezing of the diaphragm blades is not required, the degree of freedom in optical design can be increased and an optical system having good optical performance can be realized.

It is an exploded view of the diaphragm | throttle device of embodiment to which the light quantity adjustment apparatus of this invention is applied. It is a perspective view of the aperture blade of FIG. It is a front view of the aperture blade of FIG. It is a perspective view of the cam plate of FIG. It is a front view which shows the positional relationship of the aperture blade of FIG. 1, and a cam plate. It is a figure explaining the rushing phenomenon of a light quantity adjustment apparatus. It is a figure explaining the rushing phenomenon of a light quantity adjustment apparatus. It is a figure explaining the preventive measure of the rush phenomenon by the light quantity adjustment apparatus of this embodiment. It is a perspective view which shows the structure of the light quantity adjustment apparatus of the modification of this embodiment. It is a perspective view which shows the structure of the light quantity adjustment apparatus of the modification of this embodiment. It is a perspective view which shows the structure of the light quantity adjustment apparatus of the modification of this embodiment. It is a figure explaining the effect | action by the light quantity adjustment apparatus of the modification of this embodiment. It is a block diagram which shows the camera system with which the lens apparatus to which the light quantity adjustment apparatus of this invention was applied was mounted | worn. It is a perspective view of the drive part of the light quantity adjustment apparatus of this invention. It is a figure explaining attachment of the drive part of the light quantity adjustment apparatus of this invention. It is a figure explaining attachment of the drive part of the light quantity adjustment apparatus of this invention. It is a figure explaining attachment of the drive part of the light quantity adjustment apparatus of this invention. It is an enlarged view of the engaging part in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cover member 2 Magnet 3 Core 4 Rotating shaft 5 Bobbin 6 Coil 7 Washer 8 Sheet member 9 Yoke 10 Bearing 11 Pinion 12 Position detection element 13 Case member 14 Rotary plate 15 Diaphragm blade 16 Cam plate

Claims (5)

A rotating member; a driving unit that drives the rotating member; a plurality of aperture blades that are arranged so as to overlap each other so as to form an opening; and the opening formed by rotation of the rotating member; A light amount adjusting device having a cam member that operates the plurality of diaphragm blades such that the opening degree is predetermined.
In addition to forming a contact portion on the diaphragm blade, a slope portion that contacts the contact portion is formed on the cam member or the rotating member, and the contact portion is formed on the slope portion as the diaphragm blade operates. Move along,
As the plurality of diaphragm blades are operated from the open side to the small diaphragm side, the contact portion is pressed in the direction opposite to the optical system along the optical axis direction, and the aperture portion of the aperture blade in the optical axis direction is pressed. A light amount adjusting device characterized in that the slope portion is formed so as to reduce a rushing up. Each of the diaphragm blades has a shaft portion that engages with the rotating member,
The slope portion is formed between a cam hole that is an engagement portion between the rotating member and the shaft portion, and an outer periphery of an opening hole portion of the cam member, and the contact portion is in contact with the slope portion. The light amount adjusting device according to claim 1, wherein the light amount adjusting device is a formed protrusion. Each of the diaphragm blades has a shaft portion that engages with the rotating member,
The light amount adjusting device according to claim 1, wherein the contact portion is a projection portion formed on the shaft portion, and the slope portion is formed on the rotating member. A diaphragm having the light amount adjusting device according to any one of claims 1 to 3,
An optical system having a plurality of lenses;
A lens device comprising: a control unit that controls the diaphragm device and the optical system. A lens device according to claim 4;
A camera system comprising: a camera device to which the lens device is detachable.

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