JPH06123909A - Stop device - Google Patents

Abstract

PURPOSE:To enhance stopping accuracy by a stop blade by pressing the engaging projecting part of the stop blade against the guide groove of an inner clip washer by the elastic force of the stop blade generated by pressing the bent part of the stop blade against a holding ring so that it may abut on the holding ring and preventing the occurrence of backlash between the engaging projecting part and the guide groove. CONSTITUTION:In the case that the stop blade 12, the holding ring 14 and the inner clip washer 16 are mounted on a stop frame body 18, the engaging projecting part 24 of the stop blade 12 is pressed against the guide groove 26 of the inner clip washer 16 by the elastic force of the stop blade 12 which is generated by pressing the bent part 28 of the stop blade 12 against the side surface of the holding ring 24 so that it may abut on the side surface of the holding ring 24. Thus, the occurrence of the backlash due to the engagement of the engaging projecting part 24 and the guide groove 26 is prevented. By rocking the inner clip washer 16 clockwise around an optical axis 30 in the aforesaid state, the engaging projecting part 24 is slid along the guide groove 26 without the occurrence of the backlash, and the aperture of the stop is reduced. Meanwhile, by rocking the inner clip washer 16 counterclockwise around the optical axis 30 in the case of enlarging the aperture of the stop, the engaging projecting part 24 is slid along the guide groove 26 without the occurrence of the backlash, so that the aperture of the stop is enlarged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm device, and more particularly to a diaphragm device applied to an optical machine such as a camera or a video camera.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 6, a diaphragm device of this type has a plurality of diaphragm blades 1 (only one diaphragm blade is shown in this figure) between a retaining ring 2 and a chrysanthemum 3. And the holding ring 2 and the chrysanthemum 3 together with the diaphragm frame 4 so that they do not interfere with each other.
Fixed to. A rotating pin 5 is planted in the base end portion 1a of the diaphragm blade 1, and the rotating pin 5 is rotatably attached to a bearing hole 6 formed in the holding ring 2 to form a diaphragm blade. 1 is swingably positioned on the retaining ring 2. Also,
A dowel pin 7 is planted on the opposite side of the rotary pin 5 in the diaphragm blade 1, and the dowel pin 7 is engaged with a long hole-shaped guide hole 8 formed in the chrysanthemum seat 3.

When the chrysanthemum 3 is swung clockwise or counterclockwise around the optical axis 9, the dowel pin 7 of the diaphragm blade 3 moves along the guide hole 8 to cause the diaphragm blade 3 to move. Oscillates in the direction of the optical axis 9 or away from the optical axis 9 with the pivot pin 5 as the fulcrum. As a result, the aperture diameter can be enlarged or reduced.

[0004]

However, in the conventional diaphragm device, due to the rattling caused by the engagement between the dowel pin 7 of the diaphragm blade 1 and the guide hole 8 of the chrysanthemum 3, a diaphragm value in the direction of reducing the diaphragm diameter is set. Since there is a deviation from the aperture value in the direction of increasing the aperture diameter, there is a drawback that the aperture accuracy is poor. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a diaphragm device capable of improving diaphragm accuracy by eliminating rattling of a diaphragm blade and a chrysanthemum.

[0005]

In order to achieve the above object, the present invention has a plurality of diaphragm blades stacked and held between a retaining ring and a chrysanthemum, and each diaphragm blade swings on the retaining ring. In the diaphragm device, which is movably positioned and guided by the chrysanthemum through the guide hole, and swings the chrysanthemum to swing the diaphragm blade along the guide hole to expand and contract the diaphragm aperture. A bent portion that is pressed against the holding ring is formed at the tip of the diaphragm blade, and an engaging convex portion that is guided by the guide hole is formed on each diaphragm blade by press working or the like. With the elastic force of the diaphragm blade generated by pressing and contacting the bent portion of the diaphragm blade with the retaining ring, the engaging projection is pressed against the guide groove to hold the diaphragm blade between the retaining ring and the chrysanthemum. It is characterized by having done.

[0006]

According to the present invention, the engaging convex portion of the diaphragm blade is pressed against the guide hole of the chrysanthemum by the elastic force of the diaphragm blade which is generated when the bent portion of the diaphragm blade comes into pressure contact with the retaining ring. As a result, the engaging protrusion slides along the guide hole in a state where the engaging protrusion and the guide hole are not loose, so that the diaphragm precision by the diaphragm blade is improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a diaphragm device according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a perspective view of a diaphragm device 10 according to the present invention, and FIG. 2 is a cross-sectional view of an essential part thereof. As shown in FIG. 1, a plurality of diaphragm blades 12 formed in a substantially crescent shape (only one diaphragm blade is shown in this figure).
Between the donut-shaped holding ring 14 and the chrysanthemum 16 are overlapped and held so as not to interfere with each other. Further, the diaphragm blade 12 is fixed to a cylindrical diaphragm frame 18 together with a retaining ring 14 and a chrysanthemum seat 16.

A rotating pin 20 is embedded in the base end portion 12a of the diaphragm blade 12. The rotating pin 20 is rotatably attached to a bearing hole 22 formed in the holding ring 14. As a result, the diaphragm blades 12 are swingably positioned on the holding ring 14. In addition, the diaphragm device 10 of the present embodiment
Since six bearing holes 22 are formed in the retaining ring 14, six diaphragm blades 12 are used.

2 and 3 are formed on the diaphragm blade 12 on the opposite side of the rotating pin 5 by press working or the like, and the engaging projection 24 is formed by the chrysanthemum. Seat 16
Is engaged with a guide groove 26 having a long hole shape formed in.
The engaging protrusion 24 has a V-shaped cross section, and the guide groove 26 has a concave shape. Furthermore, a bent portion 28 that is inclined and bent toward the holding ring 14 is formed at the tip portion 12b of the diaphragm blade 12. As shown in FIG. 2, the bent portion 28 is pressed and abutted against the side surface of the holding ring 14 fixed to the diaphragm frame body 18 to be elastically deformed.

Next, the diaphragm device 10 configured as described above.
The action of will be described. First, when the diaphragm blade 12, the retaining ring 14, and the chrysanthemum 16 are attached to the diaphragm frame 18 as shown in FIG. 2, the folded portion 28 of the diaphragm blade 12 presses and abuts against the side surface of the retaining ring 24. Feather 1
2 by the elastic force of 2,
The guide groove 26 is pressed. As a result, rattling due to the engagement between the engaging protrusion 24 and the guide groove 26 is eliminated.

In this state, the chrysanthemum 16 is attached to the optical axis 3 shown in FIG.
When swinging clockwise around 0, the diaphragm blades 12
The engaging convex portion 24 slides along the guide groove 26 of the chrysanthemum 16 without rattling, and the diaphragm blade 12 swings in the direction of the optical axis 30 with the turning pin 20 as a swinging fulcrum. As a result, the aperture size is reduced. Further, when the aperture diameter is enlarged, the chrysanthemum seat 16 is swung counterclockwise about the optical axis 30. As a result, the engaging projection 24 is guided by the guide groove 26.
Sliding along the backlash without moving the diaphragm blade 12
Since it swings in the direction away from the optical axis 30 with the swinging fulcrum as the swinging fulcrum, the aperture diameter can be increased.

Therefore, in this embodiment, when the aperture diameter is expanded or contracted, the engaging projection 24 slides along the guide groove 26 of the chrysanthemum 16 without any play, so that the aperture value is reduced in the direction of decreasing the aperture diameter. , And the aperture value in the direction of enlarging the aperture diameter will match. Thereby, the diaphragm accuracy can be improved as compared with the conventional diaphragm device. In this embodiment, the engaging convex portion 24 is formed in a V-shaped cross section and the guide groove 26 is formed in a concave cross section. However, the present invention is not limited to this. For example, as shown in FIG. 4, the engaging protrusion 24A may be formed in a concave shape in cross section, and the guide groove 26A may be formed in a V shape in cross section. Further, as shown in FIG. 5, the engaging convex portion 24B has a spherical cross section,
Further, the guide groove 26B may be formed in a V-shaped cross section.

[0013]

As described above, according to the diaphragm device of the present invention, the engaging convex portion of the diaphragm blade is caused by the elastic force of the diaphragm blade generated by the bent portion of the diaphragm blade pressingly contacting the retaining ring. Since it is pressed against the guide hole of the chrysanthemum seat, it is possible to eliminate rattling between the engaging convex portion and the guide hole. As a result, it is possible to improve the diaphragm precision of the diaphragm blades.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a diaphragm device according to the present invention.

FIG. 2 is a sectional view of an essential part of a diaphragm device according to the present invention.

FIG. 3 is an enlarged cross-sectional view showing an engagement state between a diaphragm blade and a chrysanthemum seat of a diaphragm device according to the present invention.

FIG. 4 is an enlarged sectional view showing another embodiment in which the diaphragm blade and the chrysanthemum seat are engaged with each other.

FIG. 5 is an enlarged sectional view showing another embodiment in which the diaphragm blade and the chrysanthemum seat are engaged with each other.

FIG. 6 is a perspective view showing an embodiment of a conventional diaphragm device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... A diaphragm device 12 ... A diaphragm blade 14 ... A holding ring 16 ... A chrysanthemum 18 ... A diaphragm frame 20 ... A rotation pin 22 ... A bearing hole 24, 24A, 24B ... An engaging convex part 26, 26A, 26B ... A guide groove 28 ... Bent section

Claims (1)

[Claims] 1. A plurality of diaphragm blades are superposed and held between a retaining ring and a chrysanthemum, and each diaphragm blade is pivotally positioned on the retaining ring and is guided to the chrysanthemum through a guide hole. In the diaphragm device that swings the chrysanthemum seat to swing the diaphragm blade according to the guide hole to expand or contract the diaphragm aperture, the tip end of each diaphragm blade is pressed and abutted against the holding ring. The bent portion of the diaphragm blade is formed, and the engaging convex portion guided by the guide hole is formed on each diaphragm blade by press working or the like, and the bent portion of the diaphragm blade is pressed and abutted against the retaining ring. The diaphragm device holds the diaphragm blade between the retaining ring and the chrysanthemum by pressing the engaging convex portion against the guide groove by the elastic force of the diaphragm blade.