JPH041548Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) A telescope in a dark box camera, which is a relatively large type of camera in which the front and rear elements are mounted across a lens board, and lenses can be replaced along with the lens board. This concerns the installation of the converter.

(Prior Art) Until now, no teleconverter has been developed for this type of large dark box camera. In other words, since the lenses of this type of camera can be replaced, a variety of wide telephoto lenses are on the market, and the use of a standard lens with a teleconverter or wide converter is not considered in reality. . In small cameras, it is well known that teleconverters are mounted in front of the front element and behind the rear element.

(Problem to be solved by the invention) It is almost impossible to apply the teleconverter technology of the above-mentioned small camera to a large dark box camera.In other words, since these cameras generally have a lens of about 150 mm as standard, it takes a considerable amount of time. A large-diameter lens (especially the frontmost lens) is used, and if a teleconverter is attached to this lens, an extremely large-diameter lens is required.Also, the rear diameter of the rear lens varies and a fixed mounting diameter cannot be used. It is impossible and almost impractical to attach it to various types of lenses. Therefore, in a lens configuration in which the front element is attached to the front and the rear element is attached to the rear via the lens board, an external screw at the rear of the front element is attached further behind the rear element. With this configuration, the present invention solves the problem without the need for an extremely large diameter lens and various mounting rings.

(Means for Solving the Problems) The present invention provides a teleconverter mounting device for a dark box camera, which includes a centering step on the front outer periphery that is fitted into an optical axis hole of a lens board, and an outer side of the centering step. A set ring is provided with a fixed clamping surface that contacts the lens board, a front lens mounting screw is provided on the inner periphery of the front, an adapter mounting screw is formed on the rear, and a connecting screw that fits with the adapter mounting screw is provided around the front. This is a teleconverter mounting device for a dark box camera, characterized in that it comprises an adapter ring formed with a teleconverter mounting screw for mounting the teleconverter on the rear thereof.

(Function) Fit the centering step part of the set ring into the optical axis hole from the rear surface of the lens board, screw the front lens external screw into the front lens mounting screw from the front surface of the board, and secure the front lens with the fixed clamping surface of the set ring. Match the center to the lens board and clamp it accurately. Next, screw the rear lens onto the inner screw of the front lens formed at the rear end of the front lens from the back side of the lens board, and then attach the adapter mounting screw so as to cover the outer periphery of the rear lens using the connection screw of the adapter ring. Then, the teleconverter screw is screwed into the teleconverter mounting screw at the rear of the adapter ring.The lens board attached in this way can be attached to the front of the dark box camera for telephotography. It is something to do.

(Example) Next, one example of the device of the present invention shown in the drawings will be explained in detail.

Reference numeral 1 denotes a lens board for mounting a photographing lens for a dark box camera (not shown), and this board is provided with an optical axis hole 2 for aligning and accurately fixing the optical axes of the front and rear lenses. The front lens 3 has a front lens outer screw 4 which is inserted into the optical axis hole 2 and is screwed with a conventionally used front lens fixing ring (not shown), and a front lens inner screw into which the rear lens 6 is screwed. It has a screw 7, and a front ball internal screw 7.
A rear ball screw 8 of the rear lens 6 is screwed into the rear lens 6 to form a commonly used dark box photographing lens.

Therefore, the present invention allows the centering step portion 1 to be tightly positioned in the optical axis hole 2 without using the above-mentioned front lens fixing ring.
A settling ring a that is connected to the front lens outer screw 4 that fits into the front lens mounting screw 1 and is fixed to the lens board 1, and an adapter ring that is connected to this and is installed so as to cover the rear lens 6. Consists of b.

That is, the settling ring a has an outer periphery that fits into the optical axis hole 2 at the front, and a front ball mounting screw 1 on the inner surface thereof.
2, this screw 12 and the front ball outer screw 4 are screwed together, and the fixing clamping surface 13 comes into contact with the surface of the board 1, thereby accurately fixing the optical axis of the front ball 3 and also fixing the optical axis of the rear ball 6. The rear ball screw 8 is screwed into the front ball inner screw 7 of the front ball 3, and the rear ball 6 and the front ball 3 are precisely fixed.

The connection screw 15 of the adapter ring b is screwed into the adapter installation screw 14 at the rear of the set ring a to connect it so as to cover the entire circumference of the rear ball 6, and the teleconverter 18 is connected to the rear adapter installation screw 16 of the ring b. It is configured such that a teleconverter 18 is attached by screwing a teleconverter screw 17.

(Effect of the invention) Since the present invention is constructed as described above, the lens board, front lens, rear lens, and their related components can be fixed with high precision as before, and the teleconverter can also be connected with high precision via the adapter ring. In addition, it is possible to replace and attach various converters whose focal lengths can be changed, so there is no need to carry and carry a large number of heavy photographic lenses as in the past, making it extremely suitable as a converter for a camera using a large dark box.

[Brief explanation of the drawing]

The figures show one embodiment of the device of the present invention, in which Fig. 1 is a cutaway side view, Fig. 2A is a partially cutaway perspective view of the settling ring, and Fig. 2B is a partially cutaway perspective view of the adapter ring. It is. a...Settling, b...Adapter ring,
1...Lens board, 2...Optical axis hole, 3...Front lens, 4...Front ball external thread, 6...Rear ball, 7...Front ball internal thread, 8...Rear ball screw, 11... ...centering step,
12... Front ball mounting screw, 14... Adapter mounting screw, 15... Connection screw, 16... Converter mounting screw.

Claims (1)

[Scope of Claim for Utility Model Registration] In a teleconverter mounting device for a dark box camera, there is a centering step on the front outer periphery that fits into the optical axis hole of the lens board, and a centering step that comes into contact with the lens board on the outside of the centering step. A fixed clamping surface is provided, a front ball mounting screw is provided on the inner periphery of the front, a setting ring with an adapter mounting screw formed on the rear, and a connecting screw that fits with the above adapter mounting screw is provided around the front, and a telescope is provided on the rear. A teleconverter mounting device for a dark box camera, comprising an adapter ring formed with a teleconverter mounting screw for mounting the converter.