JPH0637403Y2 - Light amount diaphragm device for camera - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a light amount diaphragm device for a camera such as a video camera.

[Conventional technology]

Conventionally, as a diaphragm device for a video camera, there is one disclosed in Japanese Utility Model Laid-Open No. 59-4524. As shown in FIG. 11, this diaphragm device includes a base plate 330 having a light receiving opening 331, a first diaphragm blade 361 having a diaphragm opening 363, and a second diaphragm blade 364 having a diaphragm opening 364.
Of the drive pins 321, 322 of the actuating lever 320 of the drive device 310.
Is a long hole 369,370 provided on one end side of the diaphragm blades 361,362.
The two aperture blades 361 and 362 adjust the opening area of the light receiving opening 331 through the driving pins 321 and 322 by the driving of the driving device 310.

Further, the diaphragm blades 361, 362 are configured such that guide shafts 332, 333, 334, 335 provided on the main plate 330 are engaged with and guided by guide slits 365, 366, 367, 368 provided on both sides thereof.

Further, the guide shafts 332 to 335 are step shafts having flanges α and β as shown in FIG. 12 and FIG. 13, and include a pair of guide shafts 332, 334 for supporting the blade 361 facing the main plate 330 and a blade 362. Protrusions 336,337,338,3 on the base plate 330 that form a step greater than the thickness of the blades 361 with the pair of guide shafts 333,335 supporting
It is planted in 39 each.

[Problems to be solved by the device]

However, the positioning of the diaphragm device and the lens barrel is performed by the main plate 330.
Since it is done with a plurality of fixing holes 336, 337, 338 provided in the
If the tightening of the screws inserted in 337, 338 is imbalanced, the diaphragm device cannot be mounted perpendicular to the optical axis,
The image is distorted.

In addition, one side of the diaphragm blades 361 and 362 is exposed,
Since the blades 361 and 362 are supported on the main plate 330 only by the guide shafts 332 to 335, the blades 361 and 362 easily flutter in the optical axis direction, and because the camera is used in various tilt angles and postures depending on the subject, gravity, centrifugal force, The diaphragm blades 361 and 362 bend around the guide shafts 332 to 335 due to impact, and the guide slits 365 to 368
There is a risk of rubbing around the edges with the projections 336 to 339 and the flanges α and β, and hindering stable and smooth opening / closing operation.

Further, when a large impact is applied, the elongated holes 369 and 370 may come off from the drive pins 321 and 322 due to the bending of the diaphragm blades 361 and 362.

[Purpose of device]

This invention stably supports two blades from both sides by the base plate and the pressing plate, and securely connects the base plate and the pressing plate around the light receiving opening and positions them with the lens barrel, so that the usage situation can be changed. An object of the present invention is to provide a light amount diaphragm device for a camera that can stably and smoothly open and close the blade without the pin hole of the blade coming out of the drive pin.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

<Structure> As shown in FIG. 1, the diaphragm device of this embodiment includes a guide plate such as a base plate 1, two diaphragm blades 3 and 5 shown in FIGS. 5 and 6 mounted on the base plate 1, and these. The pressing plate 7 that covers the diaphragm blades 3 and 5 and the driving device 9 that drives the diaphragm blades 3 and 5.

As shown in FIGS. 2 to 4, the main plate 1 has a light receiving opening 12 provided at the center and side walls 1 provided on both sides of the light receiving opening 12.
3,14, arc-shaped actuating holes 15 and 16, arc-shaped projecting portion 17 provided at the tip, mounting holes 18 and 19, fixing hole 21 (joint portion of the end portion) Protrusions 22 and 23 for positioning in the thickness direction (optical axis direction) with respect to the lens barrel, and guide portions provided on the side walls 13 and 14 side, for example guide pins 24 and 25
A rib 28 provided inside the operating hole 15 to support the diaphragm blade 5, ribs 30 and 31 provided from the inside of the operating hole 15 and 16 toward the light receiving opening 12 to support the diaphragm blade 3, and a side wall 13. Ribs 32 that are provided in the vicinity of the
Ribs 33, 34 provided on the 17 side for supporting the diaphragm blades 3, protective projections 35, 36 around the operating holes 15, 16 and a fixing hole 43 are provided.

In addition, the ribs 28, 30, 31, 32, 33, 34 project toward the pressing plate 7 side,
The ribs 28, 32 are formed higher than the ribs 30, 31, 33, 34.

A recess 20 is provided on the periphery of the light receiving opening 12 as shown in FIG.

The side walls 13 and 14 have engaging protrusions 26, 27, 41 and 42 (side connecting portions).
And projections 10 and 1 for positioning in the thickness direction with respect to the lens barrel.
1 is provided.

As shown in FIG. 5, the aperture blade 3 includes a guide parallel to the side edge that engages with the guide pin 24, for example, a guide hole (oblong hole) 51, a pin hole 53 with which the drive pin 122 engages, and an aperture 54. Is equipped with. The aperture opening 54 is an arc portion 95 provided along the light receiving opening 12, an acute angle portion 60 connected to the arc portion 95 to form the minimum aperture 99 as shown in FIG. 10, and an aperture blade connected to the arc portion 95. 5 is provided with a bulge portion 52 for preventing interference (eating). The bulging portion 52 bulges toward the pin hole 52.

The diaphragm blade 5 has a diaphragm opening 56 having an acute angle portion 61 and a circular arc portion 96 as shown in FIG. 6 which forms a diaphragm minimum opening 99 as shown in FIG. A guide, for example, a guide hole (oblong hole) 57, a pin hole 59 with which the drive pin 121 is engaged, a protruding portion 58 for preventing interference with the diaphragm blade 3, and an edge portion 97 inclined in the opening / closing direction are provided.

As shown in FIG. 7, the pressing plate 7 has an opening 70 facing the light receiving opening 12 of the main plate 1 and operating holes 71, 72 facing the operating holes 15, 16.
, Holes 73, 74, 75 facing holes 18, 19, 21 and guide pin 2
Pins 77, 78 facing 4,25, ribs 81, 82 provided on the periphery of the operating holes 71, 72, a rib 83 provided between the operating holes 72 and 73, the opening 70 and the side Ribs provided between the parts 85,8
6, a rib 87, 88 provided on the tip side from the opening 70, a hole 84 at the tip used at the time of machining, and a hole (not shown) for engaging the engaging projections 26, 27, 41, 42. Engagement part having 79,80,89,90
(Side connecting portion). The hole 75 is the base plate 1
Together with the fixing hole (21), the end connecting portion is formed.

The ribs 81, 82, 82, 85, 86, 87, 88 project toward the main plate 1 side.

In the pressing plate 7 configured in this manner, the engaging portions 79, 80, 90 are engaged with the engaging protrusions 26, 27, 41, 42 of the main plate 1 as shown in FIG. It is attached by screwing it into the hole 21.

As shown in FIG. 10, the minimum aperture 99 formed by the apertures 54, 56 of the aperture blades 3, 5 is set at the center of the light receiving aperture 12 (center of the optical axis).

<Operation> In such a configuration, the diaphragm device is inserted into the lens barrel of the camera across the optical path, the projection 17 is used to position the tip, and the projections 10, 11, 22, 23 are used to adjust the thickness of the base plate 1. It is positioned in the vertical direction and is screwed and fixed to the lens barrel through the hole 43.

In such a state, when the diaphragm is manually set, the drive device 9 is driven in accordance with the set value, and the drive pins 121 and 122 rotate counterclockwise in an arc shape in FIG. Therefore, the diaphragm blade 3 is guided by the guide pin 25 to move to the left side, and the diaphragm blade 5 is guided to the guide pin 24 to move to the right side to form the set diaphragm aperture.

[Effect of device]

In short, the present invention has the connecting portions for connecting the main plate and the pressing plate on both sides of the main plate and the pressing plate in the direction intersecting the moving direction of the blade, and on both sides of the blade moving direction around the optical axis of the light receiving opening. Since it is provided, it is possible to reliably connect the base plate and the pressing plate around the light receiving opening and prevent the blade from fluttering in the optical axis direction.

Also, on both sides in the direction intersecting the blade movement direction of the main plate,
Moreover, since the positioning projections for aligning the optical axis direction with the lens barrel are provided on both sides of the blade movement direction around the optical axis so as to project in the optical axis direction, when mounted on the lens barrel, The position in the optical axis direction around the light receiving opening is determined by the positioning protrusion, and the two blades can be held by the base plate and the pressing plate to hold the accurate position in the optical axis direction.

Further, the center of the optical axis is provided at the end of the main plate and the holding plate on the drive unit side, and the connecting portion of the end that connects the main plate and the holding plate, and both sides in the direction intersecting the blade movement direction of the main plate and the holding plate. To the drive device side, the periphery of the operating hole is fixed from three sides by the connecting portion provided on the side of the drive device, and the base plate and the pressing plate around the operating hole are securely connected, and the blade side is provided between the pair of operating holes of the pressing plate. The protruding rib that supports the one end side of the blade in the moving direction restricts the movement of the one end side of the blade in the moving direction toward the pressing plate, and the pin hole from the drive pin to the one end side in the moving direction of the blade. It can be prevented from coming off.

[Brief description of drawings]

1 to 10 show an embodiment of the present invention,
Each figure represents the following: 1 is a side view of the diaphragm device, FIG. 2 is a front view of the main plate 1,
3 is a sectional view taken along the line AA in FIG. 2, FIG. 4 is a rear view of the main plate 1, FIGS. 5 and 6 are views showing the shapes of two diaphragm blades 3 and 5, and FIG. 7 is a holding plate. 7 is a diagram showing the structure of FIG. 7, FIG. 8 is a diagram showing a state in which diaphragm blades 3 and 5 are mounted on the main plate 1, and FIG. 9 is a diagram in which the diaphragm blades 3 and 5 are sandwiched between the main plate 1 and the pressing plate 7. FIG. 10 is a diagram showing a state, and FIG. 10 is a diagram showing a state of the minimum aperture of the diaphragm. 11 to 13 are views for explaining the conventional technique. 1 ... Main plate 3,5 ... Aperture blade 7 ... Pressing plate 9 ... Drive device 10,11,22,23 …… Positioning protrusion 12 …… Light receiving opening 21 …… Fixing hole (end coupling part) ) 24,25 …… Guide pin 26,27,41,42 …… Engagement protrusion (side engagement part) 79,80,89,90 …… Engagement part (side connection part) 51,57 ...... Guide hole 54,56 …… Throttle opening 53,59 …… Pin hole 71,72 …… Operating hole 75 …… Hole (joint part of the end) 121,122 …… Drive pin

Claims (1)

[Scope of utility model registration request] 1. A light quantity diaphragm for a camera mounted on a lens barrel for adjusting the area of a light receiving opening by movably supporting two blades in opposite directions between a base plate and a pressing plate having light receiving openings facing each other. In the device, there is a drive pin that engages with a pin hole provided on one end side in the moving direction of the two blades and extends from the main plate side to the holding plate side, and the two blades are rotated by A drive unit attached to one end side of the main plate to be moved along the holding plate, a pair of operation holes formed in the holding plate and facing a rotation region of the drive pin, and the pair of the holding plates. A protruding rib that is provided between the operation holes to project toward the blade and supports one end side of the blade in the moving direction, and a rib provided at the end of the main plate and the pressing plate on the drive device side, Of the joining ends The connecting portion is provided on both sides of the main plate and the holding plate in a direction intersecting the blade moving direction, and on both sides of the blade moving direction centered on the optical axis of the light receiving opening. Alignment with the lens barrel in the optical axis direction is provided at both sides of the coupling section and the direction crossing the blade movement direction of the main plate, and projecting in the optical axis direction on both sides of the blade movement direction around the optical axis. A light amount diaphragm device for a camera, comprising: