JP2021033126A - Aperture adjustment device, lens barrel and optical instrument - Google Patents

Abstract

To provide an aperture adjustment device that can perform a position adjustment of a drive unit.SOLUTION: An aperture adjustment device 6 has: a drive unit 22 that has a shaft; an aperture blade 16 that is driven to open and close by shaft rotation of the drive unit 22; and an aperture base plate 12 that supports the aperture blade 16 and drive unit 22. The aperture adjustment device has an eccentric plate 40 that is rotatably provided with a rotation shaft as a center to the aperture base plate 12, has a holding hole 46 in a location deviating from the rotation shaft, and the drive unit 22 is held inside the holding hole 46.SELECTED DRAWING: Figure 3

Description

The present invention relates to an aperture adjusting device, a lens barrel and an optical device.

Conventionally, as an aperture adjusting device incorporated in a lens barrel of a camera or the like, an aperture adjusting device in which a gear is attached to a shaft of a motor and a plurality of aperture blades are opened and closed by rotational movement of the gear has been used.

In such an aperture adjusting device, it is necessary to make the accuracy of the gear mounting position strict. For this reason, for example, Patent Document 1 has a configuration in which a flange on which a screw fixing portion is formed is fixed to a motor, and an abutting portion formed at a portion other than the screw fixing portion of the flange is pressed by an arm portion. A configuration that enables the rotation adjustment of the motor is disclosed.

Japanese Unexamined Patent Publication No. 2004-191772

Here, if the gear meshing accuracy is poor due to the assembly accuracy of the drive unit or the like, the torque for opening and closing the diaphragm blades may differ, or abnormal noise may occur. However, in the invention described in Patent Document 1, although the rotation of the motor can be adjusted, the position of the gear cannot be adjusted, and the meshing of the gear cannot be adjusted.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a diaphragm adjusting device capable of adjusting the position of a drive unit.

The present invention is a diaphragm adjusting device including a drive unit having a shaft, a diaphragm blade that is opened and closed by rotating the shaft of the drive unit, and a support member that supports the diaphragm blade and the drive unit. The member is rotatably provided about a rotation axis, has an eccentric member having a holding portion at a position deviated from the rotation axis, and is characterized in that a drive unit is held by the holding portion.

According to the present invention having the above configuration, since the drive unit is held by the holding portion of the eccentric member, the position of the shaft of the drive unit can be changed by rotating the eccentric member, and the meshing of the gears can be adjusted. It can be carried out.

According to the present invention, it is possible to provide an aperture adjusting device capable of adjusting the position of a drive unit.

It is the schematic which shows the optical apparatus which has the aperture adjustment device by 1st Embodiment of this invention. It is a perspective view which shows the diaphragm adjustment apparatus of the optical apparatus shown in FIG. It is a perspective exploded view which shows the diaphragm adjustment apparatus of the optical apparatus shown in FIG. It is a figure seen from the subject side which shows the aperture adjustment device of the optical apparatus shown in FIG. FIG. 5 is a view seen from the subject side with the cam seat removed, which shows the aperture adjusting device of the optical device shown in FIG. 1. It is sectional drawing along the optical axis which shows the diaphragm adjustment apparatus of the optical apparatus shown in FIG. FIG. 6 is an enlarged view of part A in FIG. It is an enlarged view of part B in FIG. It is a perspective view which showed the eccentric plate of the diaphragm adjustment mechanism shown in FIG. 2 and was seen from the image formation side. It is a perspective view which showed the eccentric plate of the diaphragm adjustment mechanism shown in FIG. 2 and was seen from the subject side. It is a perspective view which showed the eccentric plate of the diaphragm adjustment mechanism shown in FIG. 2 and was seen from the subject side. It is an enlarged plan view of the part C of the diaphragm adjustment mechanism shown in FIG. It is an enlarged plan view of the part C in the state where the fixing screw of the diaphragm adjustment mechanism shown in FIG. 2 is removed. It is an enlarged plan view of the part C in a state where the drive unit and the flange of the diaphragm adjustment mechanism shown in FIG. 2 are removed.

Hereinafter, the diaphragm adjusting device according to the first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic view showing an optical device having an aperture adjusting device according to the first embodiment of the present invention. The optical device 1 is, for example, a camera, and includes a camera body 2 and a lens barrel 4 attached to the camera body 2. The camera body 2 includes, for example, an image sensor 2A such as CMOS and a control unit 2B including, for example, an integrated circuit. The lens barrel 4 has an aperture adjusting device 6. The light that has passed through the lens barrel 4 is photographed by the image sensor 2A of the camera body 2. The aperture adjustment device 6 is connected to the control unit 2B of the camera body 2 and drives the aperture adjustment device 6 according to the intensity of the light incident on the image sensor 2A to adjust the amount of light passing through the aperture adjustment device 6. .. In the following description, the direction away from the optical axis in the plane perpendicular to the optical axis of the lens barrel 4 is referred to as outward in the radial direction.

2 to 8 show the aperture adjusting device of the optical instrument shown in FIG. 1, FIG. 2 is a perspective view, FIG. 3 is a perspective exploded view, FIG. 4 is a view seen from the subject side, and FIG. A view seen from the subject side in this state, FIG. 6 is a cross-sectional view along the optical axis, FIG. 7 is an enlarged view of part A in FIG. 6, and FIG. 8 is an enlarged view of part B in FIG. As shown in FIGS. 2 to 8, the diaphragm adjusting device 6 includes a diaphragm mechanism unit 10, a drive unit 20, and a flexible substrate 30. The lower part in FIGS. 2, 3, 6 and 7 is the subject side, and the upper part is the imaging side.

The diaphragm mechanism portion 10 includes a diaphragm base plate 12, a cam seat 14, a plurality of diaphragm blades 16, and a driving wheel 18. The diaphragm blade 16 and the driving wheel 18 are supported in the internal space formed by the diaphragm base plate 12 and the cam seat 14. Further, as will be described later, the drive unit 22 is supported by the pedestal portion 12D of the drawing base plate 12. That is, the diaphragm base plate 12 and the cam seat 14 function as support members for supporting the diaphragm blades 16 and the drive unit 22.

The drawing base plate 12 has a substantially flat annular portion 12A, an annular wall 12B erected toward the imaging side along the outer circumference of the annular portion 12A, and an annular wall 12B outside the radial direction from the edge of the annular wall 12B. It has an annular edge portion 12C extending in the direction and a pedestal portion 12D. A circular opening is formed in the center of the annular portion 12A. Further, the pedestal portion 12D is erected toward the imaging side so as to extend in the circumferential direction on the annular portion 12A. The pedestal portion 12D is formed with a circular through hole 12F and a screw hole 12H adjacent to the through hole 12F. The annular wall 12B at the portion corresponding to the pedestal portion 12D projects outward in the radial direction according to the shape of the pedestal portion 12D. The annular wall 12B at the portion corresponding to the pedestal portion 12D is located radially outward from the outer peripheral edge of the annular portion 14A of the cam seat 14. An annular reduced diameter portion 12G protruding toward the center is formed on the inner peripheral surface of the through hole 12F. An eccentric plate 40, which will be described later, is placed on the reduced diameter portion 12G in the through hole 12F. On the surface of the edge portion 12C on the subject side, recesses 12E extending outward in the radial direction are formed at equal angular intervals. The recess 12E is recessed toward the image forming side, and the depth of the recess 12E is substantially equal to the plate thickness of the cam seat 14. The drawing base plate 12 is made of, for example, resin, and the annular portion 12A, the annular wall 12B, the edge portion 12C, and the pedestal portion 12D are integrally formed.

The cam seat 14 has an annular ring portion 14A and a mounting portion 14B extending from the ring portion 14A in a direction away from the optical axis. At the center of the annular portion 14A of the cam seat 14, an opening having a diameter equal to that of the annular portion 12A of the drawing base plate 12 is formed. A plurality of cam grooves 14C that are inclined in the radial direction with respect to the circumferential direction are formed in the annular portion 14A at equal angular intervals. The mounting portions 14B are provided at equal angular intervals, and the radial outer edge of the mounting portion 14B has an arc shape having the same diameter as the outer peripheral edge of the edge portion 12C of the drawing base plate 12. The cam seat 14 is made of, for example, resin, and the annular portion 14A and the mounting portion 14B are integrally formed.

Each of the diaphragm blades 16 is made of, for example, a resin material, and is formed into a substantially arcuate flat plate. A columnar first protrusion 16A is erected on the surface of the diaphragm blade 16 on the subject side, and a columnar second protrusion 16A is erected on the surface on the image forming side at a position separated from the first protrusion 16A. Part 16B is erected. The first protrusions 16A are respectively arranged in the corresponding cam grooves 14C of the cam seat 14.

The driving wheel 18 includes an annular ring portion 18A and a gear portion 18B formed on the outer peripheral portion of the ring portion at predetermined intervals in the circumferential direction. A plurality of recesses (not shown) are formed in the annular portion 18A at intervals equal to the surface on the image forming side. The driving wheel 18 is arranged so as to be adjacent to the subject side of the annular portion 12A of the diaphragm base plate 12 in the optical axis direction and surrounded by the annular wall 12B of the diaphragm base plate 12, and can rotate around the optical axis. It is supported. The second protrusion 16B of the diaphragm blade 16 is inserted into each of the plurality of recesses of the annular portion 18A, and the diaphragm blade 16 is rotatably supported by the driving wheel 18 around the second protrusion 16B. ing. The gear portion 18B is formed in an arc shape, and gear teeth are formed on the outer surface in the radial direction. The cam seat 14 is screwed in a state where the mounting portion 14B is arranged so as to be located in the recess 12E of the throttle base plate 12. The driving wheel 18 and the diaphragm blade 16 are supported in a state of being sandwiched between the cam seat 14 and the diaphragm base plate 12.

In the diaphragm mechanism portion 10, the driving wheel 18 rotates with respect to the diaphragm base plate 12, so that the diaphragm blade 16 moves together with the driving wheel, and the first protrusion 16A of the diaphragm blade 16 is along the cam groove 14C of the cam seat 14. The diaphragm blade 16 rotates about the second protrusion 16B. As a result, the tip of each diaphragm blade 16 moves back and forth in the radial direction, and the area of the central opening surrounded by the diaphragm blade 16 can be changed to adjust the amount of light passing through.

The drive unit 20 includes a drive unit 22, a flange 24, and a fixing screw 26. The drive unit 22 is composed of, for example, a motor, and has a motor main body 22D and a shaft 22A that is rotationally driven with respect to the motor main body 22D. The motor body 22D has a neck portion 22D1 projecting in a columnar shape, and the shaft 22A extends from the neck portion 22D1. A gear 22B is attached to the shaft 22A. Further, the drive unit 22 has an input unit 22C, and the input unit 22C is connected to the flexible substrate 30. The drive unit 22 rotationally drives the shaft 22A in response to the electric power input to the input unit 22C via the flexible substrate 30.

The flange 24 is a plate-shaped member, and has a circular fixing hole 24A (FIG. 7) and a through hole 24B formed therein. The diameter of the fixing hole 24A is equal to the diameter of the neck portion 22D1 of the drive unit 22. Further, the diameter of the through hole 24B is larger than the diameter of the fixing screw 26. The flange 24 is integrated with the drive unit 22 in a state where the neck portion 22D1 of the drive unit 22 is inserted into the fixing hole 24A.

9A to 9C show the eccentric plate of the aperture adjustment mechanism shown in FIG. 2, FIG. 9A is a perspective view seen from the imaging side, FIG. 9B is a perspective view seen from the subject side, and FIG. 9C is from the imaging side. It is a plan view as seen. As shown in FIGS. 9A and 9B, the eccentric plate (eccentric member) 40 has a base portion 42 having a circular outer circumference and a protruding portion 44 having a circular outer circumference protruding from the base portion 42 toward the subject side (back surface side). The outer peripheral shape of the base portion 42 and the outer peripheral shape of the protruding portion 44 are concentric circles. Further, the eccentric plate 40 is formed with a circular holding hole (holding portion) 46 penetrating the front and back surfaces. The central axis of the holding hole 46 is deviated (separated) from the central axis (rotational axis) of the base portion 42 and the protruding portion 44. As a result, as shown in FIG. 9C, the width of the base 42 differs depending on the part, the width D1 at the 12 o'clock angle in FIG. 9C is the minimum, the width D3 at the 6 o'clock angle is the maximum, and the 3 o'clock angle. The width D2 in the above is D1 or more and D2 or less. Further, on the surface of the base portion 42, first notched portions 42A extending in the radial direction are formed at angles of 12 o'clock, 3 o'clock, and 9 o'clock in FIG. 9C, respectively. That is, the width of the base portion 42 is minimized at the position of the first notch portion 42A in the center of the three first notch portions 42A, and the positions of the central axis of the base portion 42 and the holding hole 46. It functions as a marker associated with the relationship. Further, as shown in FIG. 9B, second notched portions 44A are formed on the back surface of the protruding portions 44 at equal angular intervals. The second notch 44A formed on the back surface of the protrusion 44 has a different shape. The second notch 44A, which is one of the three second notches 44A, is formed at a position where the width of the base 42 is minimized. That is, the second cutout portion 44A functions as a mark associated with the positional relationship between the central axis of the base portion 42 and the holding hole 46.

10A is an enlarged plan view of the C portion of the diaphragm adjusting mechanism shown in FIG. 2, FIG. 10B shows a state in which the fixing screw is removed, and FIG. 10C shows a state in which the drive unit and the flange are further removed. The drive unit of this embodiment is fixed as follows. As shown in FIG. 10C, the eccentric plate 40 is fitted into the through hole 12F formed in the pedestal portion 12D of the drawing base plate 12. At this time, the eccentric plate 40 is arranged so that the base portion 42 is located in the through hole 12F so as to abut the reduced diameter portion 12G and the protruding portion 44 is located inside the reduced diameter portion 12G. As a result, the eccentric plate 40 can rotate with respect to the drawing base plate 12 around the central axis of the base portion 42 in the through hole 12F.

As shown in FIGS. 10A and 10B, the drive unit 22 is held by the eccentric plate 40 by inserting the neck portion 22D1 of the drive unit 22 into the holding hole 46 of the eccentric plate 40. Then, the fixing screw 26 is inserted into the through hole 24B of the flange 24, and the fixing screw 26 is tightened into the screw hole 12H of the drawing base plate 12. As a result, the flange 24 is fixed by the fixing screw 26, and the drive unit 22 is fixed. In this way, the drive unit 22 is fixed, and the portion of the gear 22B attached to the shaft 22A of the drive unit 22 on the optical axis side and the gear portion 18B of the driving wheel 18 are engaged with each other. Then, when the shaft 22A of the drive unit 22 rotates, the driving wheel 18 rotates, and the diaphragm blade 16 changes the area of the central opening to adjust the amount of light. In the state where the drive unit 22 is fixed (assembled state) in this way, as shown in FIG. 8, the through hole 12F and the eccentric plate 40 attached to the through hole 12F are the cam seat 14 and the drawing base plate 12. It is exposed to the objective side through the gap between them.

Here, when the gear 22B of the drive unit 22 and the gear portion 18B of the driving wheel 18 are engaged too shallowly to generate noise, or when the engagement is too deep and the drive torque is large, as described below. The position of the shaft 22A of the drive unit 22 is adjusted to adjust the engagement.

First, a method of adjusting the meshing of the gears from the image forming side of the diaphragm adjusting device 6 will be described. When adjusting the meshing of the gears from the image forming side, first, the fixing screw 26 is removed as shown in FIG. 10B, and then the drive unit 22 and the flange 24 are removed as shown in FIG. 10C. As a result, the eccentric plate 40 is exposed. In this state, the jig is inserted into the first notch 42A formed in the base 42 of the eccentric plate 40, and the eccentric plate 40 is rotated in the through hole 12F. At this time, the width of the base portion 42 can be recognized based on the positional relationship of the three first cutout portions 42A. Since the center position of the holding hole 46 of the eccentric plate 40 is eccentric with respect to the central axes of the base portion 42 and the protruding portion 44, the positions of the holding hole 46 are moved closer to or separated from each other in the radial direction by rotating the eccentric plate 40. Can be made to. Then, after rotating the eccentric plate 40 to adjust the position of the holding hole 46, the neck portion 22D1 of the drive unit is inserted into the holding hole 46 again, and the fixing screw 26 is inserted into the through hole 24B of the flange 24. Then, the fixing screw 26 is tightened into the screw hole 12H of the drawing base plate 12. This completes the adjustment of gear engagement.

It is also possible to adjust the meshing of the gears from the subject side of the aperture adjusting device 6. When adjusting the meshing of the gears from the subject side, first, the fixing screw 26 is loosened to the extent that the drive unit 22 and the flange 24 can be moved. Then, as shown in FIG. 8, the eccentric plate 40 is rotated in the through hole 12F by using a jig from the portion where the eccentric plate 40 is exposed to the subject side. At this time, the width of the base portion 42 can be recognized based on the shape of the second notch portion 44A, and the eccentric plate 40 can be rotated by inserting a jig into the second notch portion 44A. Since the center position of the holding hole 46 of the eccentric plate 40 is eccentric with respect to the central axes of the base portion 42 and the protruding portion 44, the position of the holding hole 46 is moved toward the optical axis by rotating the eccentric plate 40. Can be close or separated. Then, after rotating the eccentric plate 40 to adjust the position of the holding hole 46, the fixing screw 26 is tightened into the screw hole 12H of the drawing base plate 12 to fix the drive unit 22 and the flange. This completes the adjustment of gear engagement.

As described above, according to the present embodiment, the following effects are achieved.
In the present embodiment, the diaphragm adjusting device 6 is rotatably provided with respect to the diaphragm base plate 12 about a rotation axis, has an eccentric plate 40 having a holding hole 46 at a position deviated from the rotation axis, and has a drive unit 22. The neck portion 22D1 is held in the holding hole 46. As a result, the position of the shaft 22A of the drive unit 22 can be changed by rotating the eccentric plate 40, and the meshing of the gears can be adjusted.

Further, in the present embodiment, the eccentric plate 40 is formed with a first notch portion 42A and a second notch portion 44A associated with the positional relationship between the rotation shaft and the holding hole 46. As a result, it is possible to easily recognize how the eccentric plate 40 can be rotated so that the drive unit 22 can be arranged at a desired position.

Further, in the present embodiment, since the mark associated with the positional relationship between the rotation shaft and the holding hole 46 is composed of the first notch portion 42A and the second notch portion 44A, these first notch portions are formed. A jig can be inserted into the 42A and the second notch 44A to rotate the eccentric plate 40.

Further, in the present embodiment, the second cutout portion 44A is exposed to the outside in the assembled state. As a result, the position of the drive unit 22 can be adjusted without disassembling the aperture adjusting device 6.

Further, in the present embodiment, the flange 24 is attached to the drive unit 22, and the flange 24 can be fixed to the drawing base plate 12 by the fixing screw 26 through which the fixing hole 24A formed in the flange 24 is inserted. , The diameter of the fixing hole 24A is larger than the diameter of the fixing screw 26. Thereby, the position of the drive unit 22 can be adjusted without completely removing the drive unit 22.

1 Optical equipment 2 Camera body 2A Image sensor 2B Control unit 4 Lens lens barrel 6 Aperture adjustment device 10 Aperture mechanism part 12 Aperture base plate 12A Ring part 12B Circular wall 12C Edge part 12D Pedestal part 12E Recession 12F Through hole 12G Reduced diameter part 12H Screw hole 14 Cam seat 14A Ring part 14B Mounting part 14C Cam groove 16 Squeezing blade 16A First protrusion 16B Second protrusion 18 Driving wheel 18A Ring part 18B Gear part 20 Drive part 22 Drive unit 22A Shaft 22B Gear 22C Input 22D Motor body 22D1 Neck 24 Flange 24A Fixing hole 24B Through hole 26 Fixing screw 30 Flexible board 40 Eccentric plate 42 Base 42A First notch 44 Protruding 44A Second notch 46 Holding hole

Claims (7)

A drive unit with a shaft and
A diaphragm blade that is driven to open and close by rotating the shaft of the drive unit,
A diaphragm adjusting device including the diaphragm blades and a support member for supporting the drive unit.
It has an eccentric member that is rotatably provided with respect to the support member about a rotation axis and has a holding portion at a position deviated from the rotation axis.
A diaphragm adjusting device, characterized in that the drive unit is held by the holding portion. The eccentric member is formed with a mark associated with the positional relationship between the rotation axis and the holding portion.
The aperture adjusting device according to claim 1. The mark consists of a notch,
The aperture adjusting device according to claim 2. In the assembled state, the mark is exposed to the outside.
The aperture adjusting device according to claim 2 or 3. Has a flange attached to the drive unit
The flange can be fixed to the support member by a fixing member through which a fixing hole formed in the flange is inserted.
The diameter of the fixing hole is larger than the diameter of the fixing member.
The aperture adjusting device according to any one of claims 1 to 4. A lens barrel provided with the aperture adjusting device according to any one of claims 1 to 5. An optical device provided with the aperture adjusting device according to any one of claims 1 to 5.

Images