JPH02140728A - Diaphragm unit - Google Patents

Abstract

PURPOSE:To prevent a stop blade from falling off and to contribute to the reduction of weight and cost by constituting each engaging shaft and each stop blade so that the head part of the engaging shaft press-fits and engages with an engaging hole formed on the stop blade. CONSTITUTION:On one side of a base member 1, the 1st stop blade 23 having a notched part for adjusting a stop aperture diameter, which is formed in a nearly U-shape, and the 2nd stop blade 24 also having the notched part are arranged by positioning the 1st stop blade 23 on an inner side. Then, a driving arm 19 for integrally driving both stop blades is arranged and it is connected to the connection holes 23C and 24C of the 1st stop blade 23 and the 2nd stop blade 24 so that it can freely rotate. Thus, the stop blade is supported so that it can slide and a driving lever and the stop blade can be linked just by making the engaging shaft of a driving lever member press-fit in the engaging holes 23C and 24C. Then, the number of parts is reduced and the title unit contributes to the reduction of cost and weight.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an aperture unit consisting of two aperture blades used for adjusting exposure in a camera such as a video camera.

[Prior Art] In recent years, an aperture unit composed of two sliding aperture blades has been proposed for home video cameras due to the demand for low cost and light weight. As shown in FIG. 6, this aperture unit is made of a plastic material formed into a flat plate, and has two aperture blades 3 on the front side of a base member l having a circular aperture opening 1a formed approximately in the center. .4 is attached to prevent the aperture blades 3 and 4 from falling off with a blade holding plate P, and an electromagnetic drive unit 5 consisting of a pulse motor or the like for driving the aperture blades is attached to the back side of the base member 1. The aperture blades 3 and 4 are slid in the direction facing each other or in the direction away from each other by rotation of the drive arm 7 fixed to the drive shaft of the aperture blade 5, and the aperture is closed by the notches formed in the aperture blades 3 and 4 and overlapping with each other. The exposure amount is adjusted by making the aperture diameter variable.

Guide grooves 3a and 4a for sliding are formed on one side of each aperture blade 3.4 along the vertical direction in the figure, and these guide grooves 3a are formed in a plurality of guide dowels 2 integrally attached to the base member 1. , By fitting 4a,
The aperture blades 3 and 4 are slidable with respect to the base member 1.

Further, drive pins 8 are installed at both ends of the drive arm 7, and the drive pins 8, 8 pass through a pair of arcuate grooves 1b formed in the base member 1, and drive grooves 3b of the aperture blades 3, 4, respectively.
For example, when the drive arm 7 rotates clockwise, the aperture blades 3.4 slide toward each other to narrow the aperture diameter, and when the drive arm 7 rotates counterclockwise, they slide away from each other. The aperture diameter is enlarged. The electromagnetic drive unit 5 is fixed to the base member 1 with screws 9 via the member 6 after the drive arm 7 is fixed to its drive shaft.

[Problems to be Solved by the Invention] By the way, in the conventional aperture unit configured as described above, the aperture blades 3.4 are simply fitted into the guide dowels 2 of the base member 1, so that the aperture blades 3. In order to prevent the blade from falling off, the blade press plate P is required, which has the drawback of increasing the weight.

In addition, since the aperture blades 3 and 4 are attached to the base member 1 in an overlapping state in contact with each other, the sliding load during sliding becomes large, and the output of the drive unit 5 increases, resulting in an increase in weight and size. It has the disadvantage of inviting

Furthermore, the electromagnetic drive unit 5 and the blade holding plate P are connected to the base member 1.
Since it is necessary to fix the diaphragm unit with screws 9, it takes a lot of work to complete the diaphragm unit.If the drive arm 7 is assembled after the blade assembly, as shown in Fig. 6, it will not be fixed to the drive shaft. It is necessary to adjust the magnetization phase of the magnet and the position of the drive arm 7, which has the drawback of increasing the number of work steps.

It is an object of the present invention to solve the above-mentioned conventional drawbacks, to prevent the aperture blades from falling off without using a blade holding plate, and to reduce the weight and cost by making the assembly easy and basically eliminating the need for complicated adjustment work. This provides an aperture unit that can further contribute to down reduction.

[Means for Solving the Problems] The gist of the present invention is to move in both directions to one side of a substrate member on which an aperture aperture is formed, thereby making it possible to change the diameter of the aperture aperture. Two aperture blades are arranged, and an engagement shaft provided near both rotating ends of a rotary lever member fixed to a drive shaft of a drive means attached to the base plate member and the two aperture blades are arranged. In an aperture unit that connects blades and drives both aperture blades to change the aperture aperture diameter, a guide shaft member (having a fin formed therein) is provided along the axial direction on both sides of the aperture aperture and on one side of the substrate. Further, guide grooves that fit into the fins of the pair of guide shaft members and extend in the movement direction are formed on both sides of both aperture blades, and each guide groove has a guide groove that extends in the moving direction outside the aperture operating range. Fitting holes that can be attached and detached from each guide shaft member are provided in succession, each guide groove in the aperture blade is fitted into the constriction of each guide shaft member, and each engagement hole provided in the rotary lever member is provided in series. The shaft and each proofing blade are characterized in that the head of the engagement shaft is press-fitted into a fitting hole formed in the aperture blade with elastic deformation and is engaged with the shaft portion. It's in the aperture unit.

[Function] The diaphragm unit configured as described above has two diaphragm blades that are fitted into the fins of the guide shaft member through the fitting holes that are connected to the guide grooves of the diaphragm blades. The drive lever and the aperture blade can be connected without coming off by simply supporting the drive lever so that it can slide without falling off, and by press-fitting the engagement shaft of the drive lever member into the fitting hole.

[Example] The present invention will be described in detail below based on an example shown in the drawings.

1 and 2 are exploded perspective views showing an embodiment of an aperture unit according to the present invention, with FIG. 1 being viewed from the driving section side and FIG. 2 being viewed from the aperture blade side, respectively. FIG. 3 is a sectional view of the drive section.

10 is a flat base member made of brass material,
A circular aperture opening 11 is formed approximately in the center, and a recess 10A for accommodating a drive arm 19 is formed on one side of the upper part. The bottom wall 10B of the recessed portion 10A constitutes a part of a motor to be described later, and is provided with a bearing hole 12 for the front shaft portion of the drive shaft 25 of the motor, and a pair of holes for fixing the motor. At the bottom, a pillar 13 extends along the optical axis direction on the other side. 14 is a rotating magnet having drive shafts 25 at both ends; 15 is a pair of upper and lower coil frames around which driving and braking coils are wound; and is arranged to surround the rotating magnet 14; 16 covers the pair of upper and lower coil frames 15; A cylindrical yoke 17 is a bearing member having a bearing hole 17A that abuts the other end of the yoke 17 and pivotally supports the rear shaft portion of the drive shaft 25. These members constitute a motor, and the base member Rotating magnet 14 on top of 1. Coil frame 15. The motor assembly is completed by assembling the yoke 16 and the bearing member 17 integrally, and fastening the bearing member 17 to the pillar 13 using screws 18. Note that, in reality, there are lead wires, printed circuit boards, etc. that electrically connect the coil to the outside as components of the drive unit, but these are omitted in the figure.

On the other hand, on one side of the base member 1, there are a first aperture blade 23 having a notch for adjusting the aperture aperture formed in a substantially U-shape, and a first aperture blade 23 having a notch for adjusting the aperture aperture formed in an approximately inverted U-shape. The second aperture blade 24 having a notch for the first aperture blade 2
3 on the inside, and a drive arm 19 for driving both aperture blades together is disposed, and the drive arm 19 is press-fitted and fixed to the front shaft portion of the drive shaft 25 of the motor described above. . A first drive bin 20A and a second drive bin 20B are installed at both ends of the drive arm 19 so that the first aperture blade 23 and the second aperture blade 24 can freely rotate into coupling holes 23C and 24G, which will be described later. As shown in FIG. 4, both drive bins are connected to
A step part 20-2 is formed in the rear part of a head part 20-1 formed in a semi-spherical shape, into which the coupling holes 23C and 24C are rotatably fitted, and the first aperture blade 23 and the second aperture blade 24
In this embodiment, the first drive bin 20A coupled to the first aperture blade 23 is separated from the second drive bin 20B coupled to the second aperture blade 24 with a slight gap between them. I've made it shorter. Further, the drive arm 19 is constantly biased in the direction of closing the aperture by a spring 21 interposed on the drive shaft 25.

The first aperture blade 23 is formed into a J-shaped planar path, and the upper end of the first aperture blade 23 has a shape as shown in FIG.
A first coupling hole 23G is formed that fits into the stepped portion 20-2 of the first drive bin 20A without play, and when coupling the first coupling hole 23C to the first drive pin 20A, the first drive pin 20A is press-fitted into the head 20-1 to form the first coupling hole 23C.
Notches 23D are formed on both sides of the first coupling hole 23G to allow the entire body to elastically deform and expand.

Therefore, when the first coupling hole 23C of the first aperture blade 23 is press-fitted into the first drive bin 20A and fitted into the stepped portion 20-2, the first coupling hole 23G returns to its original diameter and its head The portion 20-1 serves as a stopper to prevent the first aperture blade 23 from falling off the first drive bin 20A.

Further, the second aperture blade 24 is formed in a substantially inverted 7-shape in plan, and has a second coupling hole 24C formed at its upper end portion to fit into the stepped portion 20-2 of the second drive bin 20B without play. Similar to the first coupling hole 23C, a cut groove 24D allows elastic deformation and expansion when press-fitting with the second drive bin 20B.
are formed on both sides of the second coupling hole 24C, and the second coupling hole 24C is formed on both sides of the second coupling hole 24C.
When G is press-fitted into the second drive bin 20B and fitted into the stepped portion 20-2, the second drive bin 20
It is prevented from falling off from B.

Further, guide grooves 23A and 2 are provided on both sides of the first aperture blade 23.
3B are formed in the vertical direction, and as shown in FIG.
Fitting holes 23A', 23 into which the heads of A and 22B fit.
B' is bored, and the width of the guide grooves 23A and 23B is smaller than the diameter of the fitting holes 23A' and 23B'.

Further, on both sides of the second aperture blade 24 there are guide grooves 24A and 2
4B are formed vertically and in the direction, and each guide groove 24A and 2
Fitting holes 24A' and 24B' into which the heads of the guide dowels 22A and 22B fit are formed at the upper end of the guide grooves 24A and 24B, and the width of the guide grooves 24A and 24B is equal to the width of the fitting holes 24A'.

The diameter is smaller than 24B°.

22A and 22B are guide dowels of the same shape implanted on both sides of the diaphragm opening, and as shown in FIG. A first fitting step 22-2 into which the 23 guide grooves 23A and 23B fit, and a second fitting step 22-3 into which the guide grooves 24A and 24B of the second aperture blade 24 fit are formed. ing. Note that the first fitting step portion 22-2 is connected to the first drive bin 20.
It is located at the same position as the stepped portion 20-2 of A in the optical axis direction,
Further, the second fitting step portion 22-3 is located at the same position as the step portion 20-2 of the second drive bin 20B in the optical axis direction.

Then, by inserting the fitting holes 23A and 23B of the first aperture blade 23 through the respective heads 22-1 of the guide dowels 22A and 22B to the first fitting stepped portions 22-2, and pulling them upward, the guides are removed. The grooves 23A and 23B fit into each of the first fitting step portions 22-2 to hold and guide the first aperture blade 23 so that it can slide in the vertical direction without falling off,
By fitting the first coupling hole 23G into the first drive bin 20A, rotation of the drive arm 19 causes the first aperture blade 23 to
can be slid vertically.

After installing the first aperture blade 23, insert the fitting holes 24A' and 24B' of the second aperture blade 24 through the respective heads 22-1 of the guide dowels 22A and 22B up to the second fitting stepped portion 22-3, respectively. By pulling it upward as it is, the guide grooves 24A and 24B fit into each of the second fitting steps 22-3,
The second aperture blade 24 is prevented from falling off while being separated from the first aperture blade 23 (by holding and guiding the second aperture blade 24 in a vertically slidable manner and fitting the second coupling hole 24G into the second drive bin 20B). By rotating the drive arm 19, the second aperture blade 24 can be slid in the vertical direction.

In addition, in the rotation range of the drive arm 19, the fitting holes 23A', 23B' of the first aperture blade 23 and the fitting holes 24A', 24B' of the second aperture blade 24 are connected to the guide dowel 2.
2A and 22B so that the guide grooves of both aperture blades do not come off the guide dowels during operation.

In addition, in the above-mentioned embodiment, the drive shaft 25 of the motor
After the drive arm 19 is attached to the drive arm 19, the first aperture blade 23 and the second aperture blade 24 are fitted into the guide dowels, and then the drive arm 19 is connected to the drive bin. The aperture blade 23 and the second aperture blade 24 are fitted into the guide dowels, and then the drive arm is fixed to the drive shaft of the motor, and the drive bin is connected to the first and second aperture blades to assemble the aperture unit. It is also possible to complete it.

In this case, since the drive arm is attached from the entire surface of the diaphragm blade, the drive bin is formed on the opposite side from the above-described embodiment, and the recess 10A for accommodating the drive arm in the base member 1 becomes unnecessary.

[Effects of the Invention] As explained above, according to the present invention, the aperture blades are supported by the guide shaft member and the engaging shaft of the rotating lever, so that the aperture blades are not attached to the substrate member. There is no need to separately provide a member to prevent the product from falling off (this reduces the number of parts and contributes to cost and weight reductions).

In addition, the two aperture blades do not come into contact with each other (by supporting them apart, there is less drive loss of the aperture blades).
The aperture blades can be driven with a small driving force, and the aperture control can be performed quickly and reliably.

In addition, since the aperture blades are supported by the guide shaft member and the engaging shaft of the rotating lever, there is no need to provide a separate member to prevent the aperture blades from falling off the board member (and the parts The number of points can be reduced, contributing to cost reduction and weight reduction.

Furthermore, by integrally assembling the driving means to the substrate member, adjustment work due to the position and the like is not necessary for mounting the driving means, and moreover, accuracy can be improved.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the aperture unit according to the present invention, FIGS. 1 and 2 are exploded perspective views of the aperture unit viewed from different directions, and FIG. 3 is a sectional view of the drive unit. It is. Figure 4 (A) is a sectional view showing the connection type between the aperture blade and the drive arm, Figure (B) is a partial plan view of the aperture blade, and Figure 5 (A) is the fitting of the aperture blade and the guide dowel. A sectional view showing the type, and FIG. 5(B) is a partial plan view of the aperture blade. FIG. 6 is an exploded perspective view of a conventional aperture unit. 10: Base member 11: Aperture opening 12: Bearing hole 13: Mounting pillar 14: Rotating magnet
15: Coil frame 16: Yoke 17: Bearing member 19: Drive arm 20A, 20B: Drive bin 21 Spring 22
A, 22B Ni guide dowels 23, 24: Aperture blades 23A, 23B, 24A, 24B Ni guide dowels 23C
, 24C: Coupling holes 23D, 24D: Cut groove 25: Drive shaft. 1st circle and 4 others Figure 4

Claims (1)

[Claims] 1. Two aperture blades that can move in both directions to change the diameter of the aperture with respect to the aperture are arranged on one side of a substrate member on which an aperture is formed, and are attached to the substrate member. The two aperture blades are connected to engagement shafts provided near both rotating ends of a rotary lever member fixed to the drive shaft of the drive means, and both aperture blades are driven to vary the aperture aperture diameter. In the diaphragm unit, guide shaft members are provided on both sides of the diaphragm opening and on one side of the substrate, with a constricted portion formed along the axial direction, and the pair of guide shaft members are provided on both sides of the diaphragm blades. A guide groove is formed that fits into the constriction of the aperture and extends in the moving direction, and each guide groove is provided with a fitting hole that can be detached from each guide shaft member outside the aperture operating range. Each guide groove part of the blade is fitted into the constriction part of each guide shaft member, and each engagement shaft provided on the rotary lever member and each aperture blade are connected so that the head of the engagement shaft is connected to the aperture blade. 1. A diaphragm unit configured to be press-fitted with elastic deformation into a fitting hole formed in a fitting hole and engaged with a shaft portion thereof. 2. The driving means according to claim 1, wherein the driving means is integrally assembled with the substrate member so that the front shaft portion of the drive shaft is supported by a bearing hole bored in the substrate member. aperture unit. 3. The aperture unit according to claim 1, wherein the guide shaft member has at least two constrictions, and the guide grooves of at least two aperture blades fit into each constriction.