JPH0462054B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an aperture blade that can be applied to an aperture device for a lens for cameras such as CCTV cameras, still cameras, and cine cameras.

[Conventional technology]

The conventional technology, as described in Japanese Utility Model Application Publication No. 50-105448, Japanese Utility Model Application Publication No. 51-40221, and Japanese Unexamined Utility Model Publication No. 52-117127, etc. An ND filter is installed and linked with opaque aperture blades so that when the aperture becomes small, the ND filter intervenes within the aperture to adjust the amount of transmitted light. -As stated in Publication No. 110281,
A colorless light-attenuating transmitting section made of a microhole or the like is provided in a part of the aperture blade to prevent over-diaphragm which would otherwise cause hunting or the like.

[Problem that the invention seeks to solve]

With the conventional technology of installing an ND filter near the opaque aperture blade, the ND filter of the aperture blade is separate, which of course complicates the configuration, but the aperture blade itself is heavy and requires a large driving force. In particular, there is a problem that shading occurs due to the spacing between the aperture blades and the ND filter. In the case of a configuration in which a colorless light-attenuating transmitting section consisting of micro holes etc. is provided, the purpose is simply to prevent the aperture from being stopped down too much due to rapid aperture reduction. No technology has been disclosed regarding how to achieve such changes.

[Means for solving problems]

Therefore, first of all, the present invention provides a CCTV camera that gradually narrows the diameter of the aperture aperture using two movable aperture blades, and eventually a portion of the aperture blades overlaps to close the aperture aperture. In the aperture blades of a wide-area aperture control device such as a commercial lens, the two movable aperture blades are printed or coated with an opaque material on a semi-transparent ND film having an arbitrary density, leaving a part of the translucent part as it is. It is composed of aperture blades having a semi-transparent part in part, and the semi-transparent part is provided so as to correspond to an overlapping part of the aperture blades that finally closes the aperture aperture, and a part of the semi-transparent part contacts the aperture aperture. A notch is provided in the opaque portion, and a correspondingly semitransparent notch portion is provided at the boundary between the semitransparent portion and the opaque portion, in which the semitransparent portion cuts into the opaque portion in a notch shape, and the notch and the semitransparent notch portion each form an aperture. A second aspect of the present invention is to provide an aperture blade configured to form a polygon in which the amount of transmitted light changes continuously and linearly in a small-diameter aperture state of the blade; The aperture blade is made by printing or coating an opaque material on both the front and back sides of a transparent ND film.

[Functions and effects of the invention]

The first configuration of the present invention combines the aperture blades and the ND filter, which were conventionally configured separately, into a single unit.
By printing or coating an opaque material on a portion of the ND film and forming an integrated aperture blade with a partially translucent ND filter, it is no longer possible to use multiple aperture blades and an independent ND filter like in the past. By eliminating the diaphragm mechanism consisting of the diaphragm mechanism and simply narrowing down two diaphragm blades, a diaphragm device with an ND filter can be configured. Since the diaphragm blades are constructed from ND film, the weight of the diaphragm blades can be reduced, making their driving particularly easy.
Since there is no space between the ND filter and the ND filter, shading can be almost prevented from occurring.Furthermore, a notch is provided in the part of the translucent part of the aperture blade that touches the aperture opening, and the translucent part and the opaque part are separated. A translucent notch-like part is provided in which the semi-transparent part cuts into the opaque part in a notch-like manner at the boundary with the opaque part, and the notch and the translucent notch-like part form a polygonal opening when the aperture aperture is small. In the present invention, the polygonal aperture, which was conventionally possible with a large number of aperture blades, is made possible with a minimum of two aperture blades, and the amount of transmitted light can be continuously and linearly adjusted. Since the amount of transmitted light is minimized, there is an effect that the aperture can be adjusted so that no shading occurs in the amount of transmitted light.Furthermore, according to the second configuration of the present invention, an opaque material is printed or printed on both sides of the aperture blades. As a result, the material on the front and back surfaces of the aperture blades is uniform, preventing warping due to environmental changes such as temperature changes, preventing adhesion caused by static electricity, and making the two aperture blades opaque to each other. By making the surfaces coated with the material touch, it is possible to eliminate the influence of the thickness of the film, prevent shading from occurring, and reduce frictional resistance, among other effects. Moreover, even if there is a pinhole in the opaque part of the surface, it is effective in preventing it from occurring from the back side.

〔Example〕

In the embodiment, an aperture device having two symmetrical aperture blades according to the present invention is shown, and a single aperture blade is shown in FIG. In the figure, 1 is the aperture mechanism main body,
It consists of a fixed part that has a fulcrum shaft 3 for the aperture blade 2, and a movable part that has a moving shaft 4 that drives the aperture blade 2. The fulcrum shafts 3 are arranged symmetrically across the diaphragm opening 5 at the center of the mechanism body 1, and the moving shaft 4 is configured to rotate counterclockwise inside the fulcrum shaft 3 to drive the diaphragm blades 2 in the diaphragm direction. It has been done. The aperture blade 2 is provided at one end with a fulcrum hole 6 into which the fulcrum shaft 3 is fitted, and a cam groove 7 into which the moving shaft 4 is fitted to rotate the aperture blade 2 around the fulcrum shaft 3. There is. In the figure, the two aperture blades 2 are stacked so that the left side is on top and the right side is on the bottom.
includes a semicircular inner edge 8 of the diaphragm so as to cover the periphery of the diaphragm opening 5 at the open position shown in FIG. 1, and a semicircular arc so as to completely cover the diaphragm opening 5 at the small diaphragm position of FIG. It has an aperture outer edge 9. The aperture blades 2 are made of a translucent ND film made of, for example, a photographic film exposed to an appropriate density or a polyester film containing blackened silver, and a part of the surface is left as a translucent part to give a glossy finish. It is constructed by printing or coating an opaque material such as erasable black ink. In the case of this embodiment, as shown in FIGS. 3 and 4, the translucent portion 10 is provided at the center of the inner edge 8 of the diaphragm, which overlaps each other when the diaphragm aperture is in a small aperture state. In the diagram, the shaded area is the semi-transparent part 1
The white part at 0 is the opaque part 11. Translucent part 1
A notch 12 is provided on the inner edge 8 of the approximately central aperture 0, and correspondingly, the translucent portion 10 has a translucent cut-out portion 1 that cuts into the opaque portion 11 in a notch shape.
3 is provided, and in the small aperture state shown in Fig. 3,
The notch 12 and the translucent cutout 13 form a substantially rectangular aperture aperture, and at the small aperture position shown in FIG. From the time of the caliber to the 4th figure through the 3rd figure
Continuous linear aperture adjustment is possible over a wide range, down to small apertures as shown in the figure. Furthermore, by making the two aperture blades 2 contact each other with their surfaces coated with opaque material, it is possible to eliminate the influence of film thickness, further prevent shading, and prevent friction. It is possible to reduce the resistance, and by appropriately setting the shape and size of the notches 12 and 13, it is possible to adjust the aperture as desired.

In addition, when the above-mentioned two aperture blades 2 are arranged so that the surfaces coated with opaque material are in contact with each other, if the two aperture blades 2 have the same shape, the lower blade is on the front surface and the upper blade is on the back surface. It is sufficient if an opaque material is applied or printed respectively.

FIG. 5 explains the manufacturing method of the aperture blades of the present invention, and 14 is a semi-transparent part having an arbitrary density.
A mask 15 shown surrounded by a solid line is applied to this surface using an ND film, and an opaque material is printed or coated.
In the case of the embodiment, a mask 1 indicated by a broken line having a slightly larger area than the mask 15 is also provided on the back side of the film 14.
6, and print or apply an opaque material in the same manner.
In this case, a mask 15 on the front side defines the exact outline of the translucent part, and a mask 16 on the back side protects the outline of this translucent part from the opaque material applied to the back side. Of course, the areas of the masks 15 and 16 may be the same as long as sufficient positioning accuracy can be obtained. After that, masks 15 and 16 are removed,
Each film piece cut out from the film 14 along the cut line shown by the dashed line is the aperture blade 2 of the present invention.
becomes. In this case, an opaque material is printed or coated on both sides of the aperture blade 2, but this makes the material on the front and back sides of the aperture blade 2 uniform,
Warping does not occur due to environmental changes such as temperature changes.
As mentioned above, it has the effect of preventing adhesion caused by static electricity and reducing frictional resistance, and even if there is a pinhole in the opaque part of the surface, it can prevent it from happening from the back side. be.

[Brief explanation of the drawing]

FIG. 1 is a front view showing how an embodiment of the present invention is used, FIG. 2 is a front view of an aperture blade according to the present invention, and FIGS. 3 and 4 are front views showing how it works. FIG. 5 is a schematic explanatory diagram showing the method for manufacturing the aperture blades of the present invention. 1...Aperture mechanism main body, 2...Aperture blade, 3...
Fulcrum axis, 4...Moving axis, 5...Aperture opening, 6...
Fulcrum hole, 7...cam groove, 8...inner edge of the aperture, 9...
...outer edge of the aperture, 10...translucent part, 11...opaque part, 12...notch, 13...translucent notch-like part,
14...ND film, 15...mask, 16...
...Mask, 17...Aperture blade cut line.

Claims (1)

[Claims] 1. A CCTV camera lens, etc., in which the diameter of the diaphragm aperture is gradually narrowed by two movable diaphragm blades, and eventually a portion of the diaphragm blades overlap to close the diaphragm aperture. In the aperture blades of a wide-area aperture control device, the two movable aperture blades are covered with a semi-transparent ND film having an arbitrary density, and a part of which is printed or coated with an opaque material while leaving a part of the translucent part as a semi-transparent part. The aperture blade has a translucent part, and the translucent part is provided so as to correspond to an overlapping part of the aperture blades that finally closes the aperture aperture, and a notch is provided in a part of the translucent part that contacts the aperture aperture. In addition, correspondingly, a translucent notch-like part is provided at the boundary between the semi-transparent part and the opaque part, in which the semi-transparent part cuts into the opaque part, and the notch and the semi-transparent notch-like part have a small diameter of the aperture blade. Aperture blades configured to form a polygon in which the amount of transmitted light changes continuously and linearly in the aperture state. 2. In a wide-range aperture control device for a CCTV camera lens, etc., in which the diameter of the aperture aperture is gradually narrowed by two movable aperture blades, and eventually a portion of the aperture blades overlap to close the aperture aperture. In the diaphragm blade, the two movable diaphragm blades are formed by printing or coating an opaque material on both the front and back surfaces of a semi-transparent ND film having an arbitrary density, leaving a part as a semi-transparent part, and printing or applying an opaque material on the part. The translucent part is provided so as to coincide with the overlapping part of the aperture blades that finally closes the aperture aperture, and a notch is provided in a part of the semitransparent part that contacts the aperture aperture, Correspondingly, a translucent notch-like part is provided at the boundary between the semi-transparent part and the opaque part, and the semi-transparent part cuts into the opaque part in a notch-like manner, and the notch and the semi-transparent notch-like part are arranged in a state where the aperture blade has a small diameter aperture. Aperture blades configured to form a polygon in which the amount of transmitted light changes continuously and linearly.