JP2012177865A - Light quantity adjustment device and optical device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light quantity adjustment device which is free from operation failure and inoperable state and allows a diaphragm blade to be smoothly opened and closed.SOLUTION: The light quantity adjustment device includes a diaphragm blade which has an exposure aperture and is supported between a pair of substrates facing each other with a prescribed gap therebetween so as to be able to open and close. The diaphragm blade includes: a base end part which is located outside the exposure aperture and has two first and second through holes formed therein; a blade substrate comprising a blade part which is moved into and away from the exposure aperture to form a diaphragm; and first and second auxiliary substrates holding the base end part of the blade substrate therebetween. The first auxiliary substrate includes: a first shaft part which is inserted through the first though hole of the base end part and is supported by one of the pair of substrates: and a first shaft hole through which a second shaft part of the second auxiliary substrate is inserted through the second through hole of the base end part. The second auxiliary substrate includes: the second shaft part which is inserted through the second through hole of the base end part and is supported by the other of the pair of substrates; and a second shaft hole through which the second shaft part of the second auxiliary substrate is inserted through the second through hole of the base end part. Axial lengths of the first shaft part and the second shaft part are set longer than the gap between the pair of substrates.

Description

The present invention relates to a light amount adjustment device that is incorporated in an optical apparatus such as a video camera or a still camera, or an optical apparatus such as a projector or other projection device, and adjusts a light amount such as a photographing light amount or a projection light amount.

In general, this type of light amount adjusting device has a substrate having an exposure opening in the photographing optical path (or projection optical path), and a plurality of light amount adjusting blades are arranged around the exposed opening of the substrate so as to be freely opened and closed. The exposure opening is known as a device for adjusting the light quantity to a large diameter or a small diameter.

For example, Patent Document 1 discloses an iris diaphragm device in which a plurality of blades are arranged around an exposure opening formed in a substrate, and an optical path aperture is opened and closed in a similar shape from a small diameter to a large diameter. Such a diaphragm device is known to be capable of adjusting the amount of light in a multistage manner with a nearly circular aperture with a large number of blades.

In this document, a plurality of diaphragm blades are arranged in a scale between a pair of front and rear ring-shaped substrates having an exposure opening in the center and around the exposure opening, and the plurality of diaphragm blades are arranged on one side of the substrate. An open / close mechanism that simultaneously opens and closes with a provided drive unit is disclosed.

Specifically, as shown in FIGS. 14 and 15, each of the seven diaphragm blades 104 has a blade portion 104a and a base end portion 104b formed by resin integral molding. A first shaft portion 104c and a second shaft portion 104d that are pivotally supported by the pair of ring-shaped substrates 100 and 110 are integrally formed on the front and back of the base end portion 104b by resin molding. The first shaft portion 104c is pivotally supported with respect to a shaft hole 110a provided in the ring-shaped substrate 110, and can be displaced around the exposure opening by the rotation of the ring-shaped substrate 110, and the second shaft portion 104d is A guide is supported so as to be slidable along a slit guide 100 a provided on the ring-shaped substrate 100. Each diaphragm blade 104 operates simultaneously to open and close the exposure opening from a small diameter to a large diameter to adjust the amount of light.

Patent Document 2 discloses another method for forming aperture blades that can be used in an opening / closing mechanism similar to that of Patent Document 1.

As shown in FIG. 16, the aperture splash is manufactured by using a laser welding technique. First, a thin sheet material to be a blade substrate is die-cut into a blade shape including a blade portion 105a and a base end portion 105b by press working. . Shaft portions 105c and 105d corresponding to the first shaft portion 104c and the second shaft portion 104d described above are abutted against the punched blades, and the joint portions 105f and 105g are irradiated with laser to be welded. In order to perform laser welding, the punched blades are black that is melted by the heat of laser irradiation, and the shafts 105c and 105d are selected from a color and material that can transmit the laser.

JP 2008-203576 A JP 2009-274217 A

However, when the blade portion 104a, the base end portion 104b, and the first and second shaft portions 104c and 104d of the diaphragm blade 104 are integrally formed by resin processing as in Patent Document 1, first, as shown in FIG. As described above, the thickness t1 of the blade portion 104a is limited by the resin molding conditions. The thickness t1 is limited to about 0.1 mm, and the thickness t0 of the blade sheet material to be punched as shown in Patent Document 2 is It cannot be made as thin as about 0.05 mm.

As a result, the amount of deflection of the blade portion 104a of the diaphragm blade 104 is too small, the blades overlap when the exposure opening is squeezed to a small diameter, and the blade portion 104a is forced to warp, causing the blades to bite smoothly. It has the problem that it is easy to cause malfunction that cannot be opened and closed.

On the other hand, as in Patent Document 2, a thin sheet material (thickness of about 0.05 mm) as a blade substrate of the diaphragm blade 105 is die-cut into a blade shape composed of a blade portion 105a and a base end portion 105b by pressing, and a shaft portion When laser welding 105c and 105d, the thickness t0 of the blade portion 105a of the diaphragm blade 105 can be reduced to about 0.05 mm, it is easy to obtain a sufficient amount of deflection, and the blades are in a state of a small diameter. Even in a state of overlapping and warping, the friction fluff acting between the blades can be suppressed to be smaller than in the case of Patent Document 1, and the blades are less likely to bite and the malfunction is considerably improved.

However, the diaphragm blade 105 made by the laser welding has the following new problem. First, when the blade portions 105a overlap with each other in a small diameter state and the blade portion 105a is warped, a load is applied to the joint portions 105f and 105g of the base end portion 105b and the shaft portions 105c and 105d, and the laser welded portion is peeled off. Easy to do.

Further, as shown in FIG. 17A, when the shafts 105c and 105d are laser-welded to the base end part 105b even if the above-described inoperability does not occur, the welding spots are attached to the plane of the base end part 105b. The shaft portions 105c and 105d are easy to tilt with the inclination angles X1 and X2, and are widened or narrowed with respect to the reference interval L0 of the shaft portions 105c and 105d. May degrade performance.

Further, by using a thin sheet material as the blade substrate, the base end portion 105b supporting the shaft portion 105d itself is also thin and easily bent. As shown in FIG. 17B, the base end portion 105b is formed by the weight of the shaft portion 105d. As a result, the tip end of the shaft portion 105d is more than necessary in contact with the slit surface of the slit groove 100a of the substrate 100, so that malfunction is likely to occur.

The present invention has been made in view of the above-described problems. Therefore, it is an object of the present invention to provide a light quantity adjusting device that can smoothly open and close the aperture blade without causing problems such as the above-described malfunction and inoperability. It is said.

In order to achieve the above object, in the light amount adjusting apparatus according to the first aspect of the present invention, a pair of substrates having an exposure opening and facing each other with a predetermined interval are supported between the pair of substrates so as to be openable and closable. A plurality of diaphragm blades for adjusting the amount of light passing through the exposure opening, the diaphragm blades being located outside the exposure opening and having at least two first and second through-holes formed thereon, and the exposure A blade substrate formed of a blade portion that advances and retreats with respect to the opening to form a diaphragm opening, and first and second auxiliary substrates that sandwich a base end portion of the blade substrate, and the first auxiliary substrate is The first auxiliary hole penetrates the first through hole in the end portion and is supported by one of the pair of substrates, and the second auxiliary substrate penetrates the second through hole in the base end portion. And a second shaft portion supported by the other of the pair of substrates, and the first shaft Axial length of the second shaft portion is set longer than the interval of the pair of substrates and.

Further, in the light amount adjusting apparatus according to the second aspect of the present invention, a pair of substrates having an exposure opening and facing each other with a predetermined interval, supported between the pair of substrates so as to be openable and closable, and passing through the exposure opening. A plurality of aperture blades for adjusting the amount of light, the aperture blades being located outside the exposure opening and having at least two first and second through holes formed therein, and advancing and retreating with respect to the exposure aperture And a first substrate and a second auxiliary substrate sandwiching the base end portion of the blade substrate, the first auxiliary substrate being a first end of the base end portion. A first shaft portion that passes through one through hole and is supported by one of the pair of substrates, and a second shaft portion of the second auxiliary substrate passes through a second through hole in the base end portion. And the second auxiliary substrate passes through the second through hole of the base end portion, and A second shaft portion supported by the other of the pair of substrates; and a second shaft hole through which the second shaft portion of the second auxiliary substrate passes through the second through hole of the base end portion. At the same time, the axial length of the first shaft portion and the second shaft portion is set longer than the distance between the pair of substrates.

According to a third aspect of the present invention, there is provided the light amount adjusting apparatus according to the present invention, wherein one of the pair of substrates constituting the first and second embodiments is a drive ring that opens and closes the plurality of aperture blades, and the drive ring. Is formed with a shaft hole that supports the first shaft portion of the auxiliary substrate, and the other substrate of the pair of substrates is a ground plate that sets an exposure opening having an open diameter, and the ground plate includes the auxiliary substrate. A slit groove for guiding the second shaft portion is formed.

Furthermore, in the optical apparatus according to the fourth aspect of the present invention, the photographing lens, the light amount adjusting device that adjusts the amount of light that passes through the photographing lens, and the light amount that is adjusted by the light amount adjusting device and passes through the photographing lens are received. It is an optical apparatus provided with the light-receiving means, Comprising: The said light quantity adjustment apparatus is provided with the light quantity adjustment apparatus as described in any one of the said Claim 1 thru | or 5.

In the light amount adjusting apparatus according to the first aspect of the present invention, a pair of substrates having an exposure opening and facing each other with a predetermined interval are supported between the pair of substrates so as to be openable and closable. A plurality of aperture blades for adjustment, the aperture blades being located outside the exposure opening and having at least two first and second through holes formed therein, and a diaphragm that advances and retreats with respect to the exposure aperture. The blade substrate is composed of a blade portion that forms an opening, and first and second auxiliary substrates that sandwich the base end portion of the blade substrate, the first auxiliary substrate being a first end of the base end portion. A first shaft portion penetrating through the through hole and supported by one of the pair of substrates; the second auxiliary substrate penetrating through the second through hole of the base end portion; The second shaft portion supported by the other has an axial length of the first shaft portion and the second shaft portion. It is set longer than the distance between the pair of substrates, the first auxiliary substrate, the second auxiliary substrate and the blade substrate are sandwiched, and the first auxiliary substrate and the second auxiliary substrate are sandwiched between the pair of substrates. The sandwiching structure provides the following effects.

As a first effect, in the present invention, the first and second shaft portions need only be fitted into the first and second through holes of the blade substrate, respectively. There is no need to fix the shaft portion of 2 by adhesion or welding.

As a second effect, in the present invention, since it is not necessary to fix by adhesion or welding, a black pigment (carbon black) whose adhesion surface or welding surface is difficult to peel off is used as a material in order to perform adhesion or welding as in a conventional product. In contrast to the special blade substrate that had been mixed in, a general blade substrate with a black pigment (carbon black) coated on the surface of the material specified by the conventional diaphragm device could be used. There is a high merit in terms of cost.

As a third effect, in the present invention, even if the first and second shaft portions rattle in the axial direction with respect to the blade substrate, there is no problem in the opening and closing operation of the diaphragm blades, and there are problems such as malfunction and inoperability. It is possible to provide a light amount adjusting device that can smoothly open and close the aperture blade without causing it.

In the light amount adjusting apparatus according to the second aspect of the present invention, a pair of substrates having an exposure opening and facing each other with a predetermined interval are supported between the pair of substrates so as to be openable and closable. A plurality of aperture blades for adjustment, the aperture blades being located outside the exposure opening and having at least two first and second through holes formed therein, and a diaphragm that advances and retreats with respect to the exposure aperture. The blade substrate is composed of a blade portion that forms an opening, and first and second auxiliary substrates that sandwich the base end portion of the blade substrate, the first auxiliary substrate being a first end of the base end portion. A first shaft portion that penetrates the through hole and is supported by one of the pair of substrates, and a first shaft portion through which the second shaft portion of the second auxiliary substrate passes through the second through hole of the base end portion. And the second auxiliary substrate passes through the second through hole in the base end portion and passes through the pair of base holes. And a second shaft hole that is supported by the other end of the second auxiliary substrate, and a second shaft hole through which the second shaft portion of the second auxiliary substrate passes through the second through hole of the base end. The axial length of the first shaft portion and the second shaft portion is set to be longer than the distance between the pair of substrates, the first auxiliary substrate, the second auxiliary substrate, and the blade substrate are sandwiched, and further the first auxiliary By adopting a double sandwich structure in which the substrate and the second auxiliary substrate are sandwiched between a pair of substrates, the first and second shaft portions are opposite to each other in addition to the first to third effects described in claim 1. Since the blade substrate is penetrated and supported from the side and the position of the blade substrate is regulated by the first and second shaft portions, the blade substrate is not displaced with respect to the first and second shaft portions. It is possible to provide a light amount adjusting device capable of performing appropriate exposure control at the aperture opening.

In the light amount adjusting apparatus according to a third aspect of the present invention, one of the pair of substrates constituting the first and second aspects is a drive ring that opens and closes the plurality of diaphragm blades, and the drive ring includes A shaft hole that supports the first shaft portion of the auxiliary substrate is formed, and the other substrate of the pair of substrates is a ground plate that sets an exposure opening having an open diameter, and the ground plate includes a second plate of the auxiliary substrate. Since the guide groove that guides the shaft part of the guide groove is formed, light leakage from the ground plane is prevented by covering the guide groove by the bottom surface of this guide groove, providing a light amount adjustment device that can perform more appropriate exposure control I can do it.

The optical apparatus according to claim 6 of the present invention has an effect that exposure control in the optical apparatus can be appropriately performed by mounting the light amount adjusting device according to any one of claims 1 to 5 described above.

The assembly exploded view of the light quantity adjustment apparatus concerning this invention. 2A and 2B are explanatory diagrams for explaining the configuration of each component in the apparatus of FIG. 1, in which FIG. 1A is a perspective explanatory view of a diaphragm blade set, and FIG. Plan view. It is explanatory drawing for demonstrating the structure of each component in the apparatus of FIG. 1, (a) is the top view which looked at the 1st board | substrate (base plate) from the aperture blade group side, (b) is the 1st board | substrate (base plate). FIG. Sectional drawing for demonstrating the arrangement | positioning relationship of each component in the assembly state of the apparatus of FIG. Sectional drawing explaining the structure of one diaphragm blade which comprises the diaphragm blade group shown in FIG. FIG. 6 is an exploded cross-sectional view of a single diaphragm blade constituting FIG. 5. FIG. 6 is a perspective view of one diaphragm blade in FIG. 5. Schematic for demonstrating the support state of the one aperture blade in FIG. The perspective view which shows the other Example of the one aperture blade of FIG. Explanatory drawing which shows the opening-and-closing locus | trajectory of the aperture blade in the apparatus of FIG. It is an operation state explanatory view of a diaphragm blade in the device of Drawing 1, (a) is a state figure of a large aperture, and (b) is a state diagram of a small aperture. Explanatory drawing of the electromagnetic drive unit in the apparatus of FIG. The conceptual explanatory drawing of the imaging device incorporating the apparatus of FIG. Sectional drawing for demonstrating the principal part for demonstrating the structure of the conventional aperture unit. Sectional drawing for demonstrating the problem of the aperture blade shown in FIG. Sectional drawing for demonstrating the principal part for demonstrating the structure of the other conventional aperture unit. Sectional drawing for demonstrating the problem of the aperture blade shown in FIG.

The present invention will be described below based on preferred embodiments shown in the drawings. FIG. 1 is an exploded view of a light amount adjusting device A according to the present invention. As shown in FIG. 1, the light amount adjusting device A includes a first substrate (base plate) 10, a diaphragm blade set 20, a second substrate (drive ring) 30, and a pressing member 40. The aperture blade group 20 is incorporated between the first substrate 10 and the second substrate 30 so as to be movable. With this configuration, the diaphragm blade set 20 is sandwiched between the first substrate 10 and the second substrate 30, and the first substrate 10 and the second substrate 30 in the sandwich shape are integrated with the pressing member 40 with a fixing screw. (Not shown).

Hereinafter, each component will be described with reference to FIGS. 2A is a perspective explanatory view of the aperture blade assembly, FIG. 2B is a plan view of the second substrate (holding plate) viewed from the aperture blade mounting surface side, and FIG. 3A is the first substrate. FIG. 3B is a perspective explanatory view of the first substrate (base plate), and FIG. 4 is a cross-sectional view for explaining the positional relationship of each component in the assembled state of the apparatus of FIG. 5 is a cross-sectional view for explaining the structure of one diaphragm blade constituting the diaphragm blade set shown in FIG. 4, FIG. 6 is an exploded sectional view of one diaphragm blade constituting FIG. 5, and FIG. FIG. 10 is an explanatory view showing an opening / closing locus of the diaphragm blade in the apparatus of FIG.

[Configuration of the first substrate]
First, the configuration of the first substrate 10 shown in FIG. 3 will be described. The first substrate 10 is a member that is generally called a ground plane and serves as a reference for mounting the apparatus.

The base plate 11 has an exposure opening 12 and is configured in a shape corresponding to the lens barrel shape of the imaging apparatus. The base plate 11 is made of metal, resin or the like and has a material / dimension that gives the device toughness. The illustrated ground plane 11 is formed by molding a synthetic resin mixed with reinforcing fibers such as glass fibers. This is because the main plate 11 is thin, small and light.

The base plate 11 is provided with an exposure opening 12 in the center, and the periphery of the opening forms a blade support surface 11x (flat surface or uneven surface) that supports the diaphragm blades 21, and guides the diaphragm blades in the opening / closing direction on the support surface 11x ( A guide groove 13 is formed for movement restriction. The configuration of the guide groove 13 will be described later. 14 is a connection protrusion for fixing the pressing plate 41, and a screw hole is formed inside the protrusion. The guide groove 13 is not a hole penetrating the substrate, but forms a guide surface that slidably guides the second shaft portion 24a of the diaphragm blade 21 and a bottom surface that shields light from leaking from other than the exposure opening 12. However, it may be a guide groove that is common in the conventional apparatus.

[Configuration of diaphragm blade group]
Next, the configuration of the aperture blade assembly 20 will be described with reference to FIG. The diaphragm blade set 20 is composed of a plurality of diaphragm blades 21 (21a to 21i) as shown in the drawing. The illustrated diaphragm blade 21 is composed of nine blades, and each blade has the same shape. FIG. 10 shows an operating state of the diaphragm blade 21, and the base end portion 21 x is supported by the above-described base plate 11. The blade portion 21y of the blade opens and closes the exposure opening 12. At this time, the blade portions 21 of the plurality of blade members overlap each other like a scale, and the exposure opening 12 is narrowed between the large diameter of FIG. 11A and the small diameter of FIG.

The diaphragm blades 21 (21a to 21i) will be described in detail with reference to FIGS. First, as shown in FIG. 6, the diaphragm blade 21 includes a blade substrate 22, an auxiliary first substrate 23, and an auxiliary second substrate 24. The blade substrate 22 is a base material that constitutes a blade portion 22a and a proximal end portion 21x constituting the blade portion 21y by pressing a sheet material obtained by rolling a resin material (polyester) mixed with a black pigment into a sheet shape by rolling. This is a die cut into a blade shape composed of the portion 22b. The base end portion 22b is formed with a positioning hole 22c through which the first shaft portion 23a of the auxiliary first substrate 23 passes and a positioning hole 22d through which the second shaft portion 24a of the auxiliary second substrate 24 passes. On the other hand, the auxiliary first substrate 23 is formed of a resin material (polycarbonnet) in a shape substantially similar to the outer shape of the base end portion 22 b, and the first shaft portion 23 a (operation pin) and the second of the auxiliary second substrate 24 are formed. A fitting hole 23b through which the two shaft portions 24a (guide pins) pass is formed. In addition, the auxiliary second substrate 24 is the auxiliary first substrate 23 inverted, and the same member can be used. The second shaft portion 24a (guide pin) and the first shaft portion 23a of the auxiliary first substrate 23 can be used. A fitting hole 24b through which the (operation pin) passes is formed.

Then, as shown in FIGS. 5 and 7, the first shaft portion 23a of the auxiliary first substrate 23 is inserted into the positioning hole 22c of the blade substrate 22, and the fitting hole 24b of the auxiliary second substrate 24 on the opposite side is inserted. The first shaft portion 23 a of the auxiliary first substrate 23 is projected to the opposite side of the blade substrate 22. At the same time, the second shaft portion 24a of the auxiliary second substrate 24 is inserted into the positioning hole 22d of the blade substrate 22 and is fitted into the fitting hole 23b of the auxiliary first substrate 23 on the opposite side. The second shaft portion 24 a is protruded to the opposite side of the blade substrate 22. In this way, the blade substrate 22 and the auxiliary second substrate 24 are sandwiched and supported by the first shaft portion 23a of the auxiliary first substrate 23 and the second shaft portion 24a of the auxiliary second substrate 24 from the opposite directions, thereby supporting the blade substrate 22 and the auxiliary second substrate 24. The first substrate 23 and the auxiliary second substrate 24 are integrated to form a single diaphragm blade 21.

The blade substrate 22 sandwiched and supported by the auxiliary first substrate 23 and the auxiliary second substrate 24 in this way is further sandwiched and supported by the first substrate 10 and the second substrate 30 as shown in FIG. Each of the first shaft portion 23a of the first substrate 23 and the second shaft portion 24a of the auxiliary second substrate 24 does not come off from the positioning holes 22c and 22d of the blade substrate 22, and the blade substrate 22 as in the conventional device. In addition, there is no need to weld and bond the auxiliary first substrate 23 and the auxiliary second substrate 24 to each other, and there is no possibility of malfunction or inoperability.

This will be described in detail with reference to FIG. FIG. 8 is a schematic diagram for explaining the support state of one diaphragm blade in FIG. 4, and FIG. 8 (a) shows that the integrated diaphragm blade 21 is fitted to the blade substrate 22 by vibration and impact. Both the auxiliary first substrate 23 and the auxiliary second substrate 24 are shown separated from the blade substrate 22, and FIG. 8B shows a single integrated diaphragm blade 21 at a preset reference position. FIG. 8C shows a state where one integrated diaphragm blade 21 is displaced to the first substrate (base plate) 10 side due to the influence of the apparatus posture, and FIG. d) shows a state in which the integrated diaphragm blade 21 is displaced toward the second substrate (driving ring) 30 due to the influence of the apparatus posture. 8A to 8D, the first shaft portion 23a of the auxiliary first substrate 23 extends from the shaft hole 33 of the second substrate (drive ring) 30 as shown in the figure. Similarly, the second shaft portion 24 a of the auxiliary second substrate 24 is not detached from the guide groove 13 of the first substrate (base plate) 10. Therefore, the blade substrate 22 that is fitted and supported by the first shaft portion 23a of the auxiliary first substrate 23 and the second shaft portion 24a of the auxiliary second substrate 24 is either of FIG. 8A to FIG. 8D. Even in this state, the first substrate (ground plate) 10 and the second substrate (drive ring) 30 are always reliably supported, and as a result, there is no possibility of malfunction or inoperability.

In order to maintain such a state, the auxiliary first substrate 23 has a predetermined distance L0 between the first substrate (ground plate) 10 and the second substrate (drive ring) 30 as shown in FIG. First shaft portion 23a
The axial length L1 of the second substrate 24 and the axial length L2 of the second shaft portion 24a of the auxiliary second substrate 24 are both in the state of FIG. 8A to FIG. The length is set in advance so as not to be disengaged from the shaft hole 33 and the guide groove 13 of the first substrate (base plate) 10.

<Other embodiments>
Further, as shown in FIG. 9, the first shaft portion 23a of the auxiliary first substrate 23 is inserted and fitted into the positioning hole 22c of the blade substrate 22, and the first shaft portion 23a of the auxiliary first substrate 23 is inserted into the blade. It protrudes to the opposite side of the substrate 22. At the same time, the second shaft portion 24 a of the auxiliary second substrate 24 is inserted and fitted into the positioning hole 22 d of the blade substrate 22, and the second shaft portion 24 a of the auxiliary second substrate 24 projects to the opposite side of the blade substrate 22. Let In this way, the blade substrate 22 and the auxiliary second substrate 24 are sandwiched and supported by the first shaft portion 23a of the auxiliary first substrate 23 and the second shaft portion 24a of the auxiliary second substrate 24 from the opposite directions, thereby supporting the blade substrate 22 and the auxiliary second substrate 24. The one substrate 23 and the auxiliary second substrate 24 can be integrated to constitute one diaphragm blade 21. However, since the auxiliary first substrate 23 and the auxiliary second substrate 24 are rotatably supported with respect to the blade substrate 22, respectively, unlike the above-described embodiment, the auxiliary substrate 22 and the auxiliary second substrate 24 have a shape that does not affect the other even if the auxiliary substrate rotates. There is a need to.

[Configuration of the second substrate]
Next, the configuration of the second substrate 30 will be described with reference to FIG. The second substrate 30 is generally called a drive ring, and is a member that opens and closes the aperture blades 21 (21a to 21i) in response to the drive of the drive unit M. The drive ring 31 is pressed as shown in FIGS. The plate 41 is rotatably attached.

As shown in the figure, the drive ring 31 is formed in a ring shape having an exposed opening 12 at the center by resin molding, for example, and a flange 32 and an engaging protrusion 34 are formed on the periphery of the exposed opening 12. The flange 32 is fitted in the opening 43 of the pressing plate 41 and rotates around the rotation center that coincides with the center of the exposure opening 12.

Further, the drive ring 31 is rotatably incorporated in the presser plate 41 as described above, and passive teeth 35 are formed on a part of the periphery thereof. The passive teeth 35 are provided at positions that mesh with a drive gear 53 of a drive unit M, which will be described later, attached to the attachment seat 46 of the presser plate 41.

Further, the drive ring 31 is provided with a fitting hole 33 on the periphery of the exposure opening 12 for fitting with the first shaft portion 23a (operation pin) of the auxiliary first substrate 23 implanted in each of the diaphragm blades 21a to 21i. It has been. A plurality of fitting holes 33 (nine in the drawing) are arranged on the periphery of the exposure opening 12 in accordance with the number of aperture blades 21.

  In such a configuration, the drive ring 31 is rotatably supported by the holding substrate 41 and is rotated by a predetermined angle by the drive gear 53 of the drive unit M. And rotation of the drive ring 31 will be transmitted to each blade member 21a-21i.

“Configuration of holding plate”
As shown in FIG. 3, the pressing plate 41 is formed in a ring shape having an opening 43 in the center, and is formed in substantially the same shape as the above-described ground plate 11. The illustrated holding plate 41 is formed by resin molding, and a mounting seat 46 for the drive unit M is provided on a part of the outer periphery. A drive unit M, which will be described later, is fixed to the mounting seat 46 with screws or the like. 45 shown in the figure is a connecting hole for screwing the pressing plate 41 to the connecting projection 14 of the base plate 11.

[Configuration of drive unit]
FIG. 12 shows an embodiment of the drive unit M. The drive unit M shown in the figure is a so-called pulse motor including a magnet rotor 50, a stator coil 51, a drive rotating shaft 52, a drive gear 53, and a yoke 54. The magnet rotor 50 is constructed by integrating a drive rotating shaft 52 and a permanent magnet 56, and a stator coil 51 is provided around the magnet rotor 50 with coils 58 wound around a core 55 at equal intervals. ing. The permanent magnet 56 has an NS pole formed on the outer periphery thereof, and a drive gear 53 is attached to the drive rotary shaft 52.

The drive unit M configured in this manner fixes the bracket 57 to the mounting seat 46 of the holding plate 41 with screws or the like. Then, the drive gear 53 is engaged with the passive teeth 35 of the drive ring 31. As a result, the drive ring 31 reciprocates a predetermined angle in the clockwise direction and the counterclockwise direction in FIG.

[Explanation of equipment assembly process]
Next, the assembly process of the light quantity adjusting device A will be described with reference to FIGS. First, as shown in FIG. 1, the drive unit M is attached to the holding plate 41, and the holding plate 41 to which the drive unit M is attached is set on the work table. As shown in FIG. 2 (b), the engagement protrusion 34 of the drive ring 31 is pushed onto the holding plate 41 so that the passive gear 35 of the drive ring 31 of the second substrate 30 meshes with the drive gear 53 of the drive unit M. The drive ring 31 is rotatably attached to the holding plate 41 by being inserted into the opening 43.

2B, the second shaft portions (operation pins) 23 of the first to ninth aperture blades 21a to 21i are connected to the drive ring 31 of the drive ring 31 as shown in FIG. The first to ninth aperture blades 21a to 21i are sequentially overlapped while being fitted into the fitting hole 33. In addition, as shown in the drawing, the blade portion 21y of the ninth diaphragm blade 21i that is finally stacked is inserted so as to be under the base end portion 21x of the first diaphragm blade 21a. By performing this assembly, any one of the first to ninth diaphragm blades 21a to 21i is located above the one diaphragm blade 21 with respect to the adjacent diaphragm blade 21, and to the other diaphragm blade. Can be stacked in a so-called scale-like state in a state of being located on the lower side. By narrowing the diaphragm blades stacked in a scale like this to a small aperture, the blade portions of the first to ninth aperture blades 21a to 21i are overlapped as shown in FIG. Thus, even if the first substrate 10 is not supported, it can be held substantially parallel to the aperture opening plane.

Next, as shown in FIG. 1, the first substrate 10 is overlaid on the diaphragm blades 21 a to 21 i, and the first shaft portion (guide pin) 24 a of each blade member 21 is placed in the guide groove 13 of the base plate 11. Store in.

Finally, the base plate 11 and the holding plate 41 are fixed with fixing screws. As a result, the first substrate 10 (base plate 11), the diaphragm blade group 20 (diaphragm blade 21), the second substrate 30 (drive ring 31), and the pressing member 40 (pressing plate 41) are sequentially stacked upward as shown in FIG. Combined and united.

[Aperture blade opening and closing operation]
Next, the opening / closing operation of the aperture blade will be described with reference to FIGS. FIG. 11A shows a large aperture state by arranging a plurality of aperture blades 21 (21a to 21i) around the exposure opening 12, and FIG. 11B shows a small aperture state. As shown in the drawing, a plurality of aperture blades 21a to 21i are arranged around the exposure opening 12 at positions separated by a predetermined angle with respect to the optical path center O (in the illustrated case, nine blades are separated by an angle of 40 degrees). It is arranged in a scale shape. FIG. 10 shows the opening / closing operation state of one of the plurality of diaphragm blades 21 (21a to 21i). Each diaphragm blade 21 (21a to 21i) has a guide pin 24a in a guide groove 13 formed in the base plate 11. And the operating pin 23 a formed on each diaphragm blade 21 (21 a to 21 i) is fitted in the shaft hole 33 of the drive ring 31.

The drive ring 31 is rotated clockwise and counterclockwise within a predetermined angle range by the drive unit M described above about the optical path center O. The blade opening / closing operation at this time will be described with reference to FIG. The actuating pin 23a rotates in the clockwise direction from the c point to the d point in the figure along the arc path xx having the radius L from the optical path center O in the figure by the rotation of the drive ring 31. The guide pin 24a moves from the point a to the point b along the guide groove 13 along the y-7y locus shown in the drawing.

The movement of the operating pin 23a and the guide pin 24a causes the diaphragm blade 21 to open and close from the solid line (large aperture state) to the broken line (small aperture state). In the illustrated apparatus, the exposure opening 12 is set to the small aperture state when the aperture is in the small aperture state, and is set to the fully open state when the aperture is in the large aperture state. Accordingly, the diaphragm blades 21 are opened and closed with an arbitrary aperture diameter from the small aperture state to the fully open state in accordance with the current supplied to the drive unit M, and the amount of light passing through the exposure aperture 12 is adjusted in magnitude.

[Configuration of optical equipment]
Next, an optical apparatus using the above-described light amount adjusting device A will be described with reference to FIG. The aforementioned light amount adjusting device is incorporated in a lens barrel of a camera device such as a still camera or a video camera. B in the figure is a front lens disposed in the photographing optical path, and C is a rear lens. The image of the subject is formed by these lenses, and the image pickup means S is disposed on the image formation plane. As the imaging means S, a solid-state imaging device such as a CCD or a photosensitive film is used. The control is configured to be executed by a CPU control circuit, an exposure control circuit, and a shutter drive circuit. In the figure, SW1 is a main power switch, and SW2 is a shutter release switch. In addition, an autofocus circuit or the like is used for control as a camera device, but since it has a well-known configuration, description thereof is omitted.

Therefore, a diaphragm device E and a shutter device (not shown) are assembled between the front lens B and the rear lens C incorporated in the lens barrel. The aperture device E incorporates the aperture blade 21 and the drive unit M described above. Therefore, the control CPU sets photographing conditions such as the exposure amount and shutter speed, and issues an instruction signal to the exposure control circuit and the shutter drive circuit. First, the exposure control circuit supplies a current in a predetermined direction to the coil of the driving device M in response to an instruction signal from the control CPU. Then, the diaphragm blade 21 transmits the rotation of the driving device M from the operating pin 23 via the driving gear 53, and narrows the exposure opening 12 to the optimum exposure amount.

Next, when the release button is operated, in the case of a solid-state imaging device such as a CCD, the charge that has already been charged is released, and photographing is started. Accordingly, the shutter driving circuit supplies a current in the shutter closing direction to the coil of the driving device in response to a shutter operation start signal after a preset exposure time has elapsed from the control CPU. After this shutter operation, when the imaging means S is a CCD (solid-state imaging device), the image data is transferred to the image processing circuit and stored in a memory or the like.

In addition to camera devices such as still cameras and video cameras, the light amount adjusting device described above is mounted on, for example, a projection lens and an optical device such as a projector or an optical microscope that illuminates a subject with light passing through the projection lens. Can be used.

A Light quantity adjustment device M Drive unit 10 First substrate (base plate)
11 Ground plate 12 Exposed opening 13 Guide groove 20 Diaphragm blade group 21 Diaphragm blade 21x Base end portion 21y Blade portion 22 Blade substrate 23 Auxiliary first substrate 23a First shaft portion 23b Fitting hole 24 Auxiliary second substrate 24a Second Shaft portion 24b Fitting hole 30 Second substrate (drive ring)
31 Drive ring 33 Shaft hole 40 Holding member 41 Holding plate

Claims (4)

A pair of substrates having exposed openings and facing each other at a predetermined interval;
A plurality of diaphragm blades supported so as to be openable and closable between the pair of substrates and adjusting the amount of light passing through the exposure opening,
The diaphragm blades are
A base end portion that is located outside the exposure opening and has at least two first and second through holes formed thereon, and a blade substrate that includes a blade portion that moves forward and backward with respect to the exposure opening to form a diaphragm opening;
The first and second auxiliary substrates sandwiching the base end portion of the blade substrate,
The first auxiliary substrate has a first shaft portion that passes through the first through hole of the base end portion and is supported by one of the pair of substrates.
The second auxiliary substrate has a second shaft portion that penetrates the second through hole of the base end portion and is supported by the other of the pair of substrates,
An apparatus for adjusting light quantity, wherein an axial length of the first shaft portion and the second shaft portion is set longer than an interval between the pair of substrates. A pair of substrates having exposed openings and facing each other at a predetermined interval;
A plurality of diaphragm blades supported so as to be openable and closable between the pair of substrates and adjusting the amount of light passing through the exposure opening,
The diaphragm blades are
A base end portion that is located outside the exposure opening and has at least two first and second through holes formed thereon, and a blade substrate that includes a blade portion that moves forward and backward with respect to the exposure opening to form a diaphragm opening;
The first and second auxiliary substrates sandwiching the base end portion of the blade substrate,
The first auxiliary substrate penetrates the first through hole of the base end portion and is supported by one of the pair of substrates and the second through hole of the base end portion A first shaft hole through which the second shaft portion of the second auxiliary substrate passes,
The second auxiliary substrate passes through the second through hole in the base end portion and is supported by the other of the pair of substrates and the second through hole in the base end portion. Having a second shaft hole through which the second shaft portion of the second auxiliary substrate passes,
An apparatus for adjusting light quantity, wherein an axial length of the first shaft portion and the second shaft portion is set longer than an interval between the pair of substrates. One of the pair of substrates is a drive ring that opens and closes the plurality of aperture blades,
A shaft hole for supporting the first shaft portion of the auxiliary substrate is formed in the drive ring,
The other substrate of the pair of substrates is a ground plate that sets an exposed opening having an open diameter,
The light quantity adjusting device according to claim 1 or 2, wherein a guide concave groove for guiding the second shaft portion of the auxiliary substrate is formed in the base plate. A taking lens,
A light amount adjusting device for adjusting the amount of light passing through the photographing lens;
An optical device comprising a light receiving means for receiving a light amount adjusted by the light amount adjusting device and passing through the photographing lens,
An optical apparatus comprising the light amount adjusting device according to any one of claims 1 to 5.