JPS58182966A - Video camera - Google Patents

Abstract

PURPOSE:To cut off an external radio wave and to remove a touching noise of a hand during operation, by mixing conductive metallic materials having less electric resistance such as Al and Ni with a plastic resin material, and connecting a structure to the earth point of an electric circuit. CONSTITUTION:The camera body structure 31 is formed of the plastic resin containing mixed conductive materials such as carbon black and Al powder and connected to the earth point of the electric circuit of the image pickup device of the camera. Then, a lens holding cylinder 34 is formed of plastic resin containing mixed conductive materials and has a relay lens barrel 36 for holding an image- forming lens internally. This cylinder 34 is fixed to the structure 31 with a screw 35. The lens barrel 36 is made of Al, etc., and fitted in the cylinder 34, and this is grounded with the screw 35 through the cylinder 34 and structure 31. Similarly, a cam ring 39, fixed lens barrel 37, and focusing holder 40 are also grounded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video camera, particularly one that receives radio waves from the outside.

Conventionally, this type of structure used metal materials such as Tki alloy or zinc die cast, and there was no need to pay special attention to electrical conduction (the lead effect).However, in recent years video cameras have 2. In % hump squid kametsu @
Due to the desire for lids, compactness, and low cost, plastic resins have been used as materials for structures. However, such a bidet has a mixture of plastic parts and 4 metal parts, and because the ground metal parts of the electric road are floating, it may cause electrical noise due to radio waves coming in from the outside, or operation. There has been a drawback in that the sheet image is severely deteriorated due to electrification over time.

A conventional example is shown in Fig. 1 (→, (b). 1 is a camera body structure, which is made of a metal material such as an aluminum frame and die cast. 2 is a camera body structure attached to the structure 1. The image pickup tube 5 is connected to a recorder or the like through a cable for power and signal transmission connected to the electric path of the imaging device housed in the structure 1, and the grounding portion of the power source is connected to the electric path through the electric path. The T-scanning of the structure 1 is being carried out. Reference numeral 4 denotes a photographic lens holding cylinder (made of a metal material such as aluminum), which is electrically connected to the structure 1 with a mounting screw 5. 6) The relay barrel of the photographic lens system holds the imaging lens, and is fitted with the photographic lens holding tube 4 to provide electrical continuity through the fitting part or a fixing screw to the holding tube 4. In this way, if the photographic lens barrel parts are made of metal, make them electrically conductive to the electric circuit inside the camera body (through the fitting part, island sliding part, and screw tightening part). be able to.

However, since everything had to be made of metal materials, there were drawbacks such as increased weight, increased material costs and processing costs due to metal processing, and poor mass production.

In addition, Figure 1 ('b) shows an example in which the parts shown in Figure 1 (-) are replaced with resin materials such as plastic.In order to shield radio noise, the surface of the plastic material is coated with a metal with low electrical resistance. It is coated with a thin film of

Reference numeral 11 denotes the structure of the camera body, which is molded from a plastic resin material. 11 & is a metal thin film for covering the surface side and inner surface of the camera structure 110; 12 is an image pickup tube; 15
is a cable for signal transmission with the camera source and the recorder, and connects the metal thin film 11& on the surface of the structure 11 to the power supply ground via an electric path (not shown). Reference numeral 14 denotes a photographing lens holding barrel, which is molded from a plastic material and houses a relay lens barrel 16 holding an imaging system lens therein. HoN*
14 and the relay lens barrel 16 require precision,
The inner and outer diameter fitting parts are coated with a thin metal film, and the relay tube 1 is coated with a thin metal film.
6 and the structure 11 are not electrically connected to each other. Also 19
is made of cam steel (Al-1-Ni-P-5 alloy, etc.) in a normal zoom lens, and has cam grooves for displacing the variable power lens 21 and the correction lens 22 in S movement. Normal cam ring 19
is thin and has a cam lift that requires 14 degrees, so a metal material such as aluminum is used because it is difficult to achieve the required angle with a plastic material. The cam ring 19 fits into the inner diameter of the fixed lens barrel 17 and rotates and slides within the fixed lens barrel 17 in conjunction with the zoom operation ring 18. The fitting part between the fixed lens barrel 17 and the cam ring 19 also requires precision, and since it is a rotating and sliding part, coating the J4 part of the fixed barrel 17 with a thin metal film or the like is difficult due to the thickness of the M1 film to be coated. not uniform,
Further, since strength against sliding friction is required, the fitting portion cannot be coated. For this reason, the cam ring 19 is in a floating state within the fixed lens barrel 17 without being grounded to the electric circuit within the camera body, and receives radio wave noise, causing unpleasant noise in the image. Reference numeral 20 denotes a focusing lens holder that holds a focusing lens, is fitted into the fixed lens barrel 17 in a heracoidal manner, and is rotated integrally in response to the rotational operation of the distance ring 25.

Since the focusing lens holder 20 has a helicoidal threaded portion, it is highly desirable to use an aluminum alloy in combination with the helicoidal threaded portion of the fixed lens barrel 17. Therefore,
The metal material of the focusing lens holder 20 is also not grounded to the camera body 1 and is in a floating state, which has the disadvantage that it receives radio wave noise and generates noise in the photographed image.

The present invention aims to provide a bidet device that eliminates the above-mentioned drawbacks, and includes a metal material with low electrical resistance such as aluminum or nickel in the plastic resin material constituting the body of the camera, or a metal material with low electrical resistance such as aluminum or nickel. The object of the present invention is to provide a video camera in which a conductive material such as carbon is mixed and the structure is grounded in an electric circuit.

FIG. 2 shows an embodiment of the present invention, in which 51 is a camera body structure, which is molded from a plastic resin mixed with four conductive materials such as a platter, aluminum powder, etc., and a camera imaging device (not shown). The ground Kt of the electric circuit that constitutes one! It is grounded. 62 is a recording tube stored in the camera (7); 56 is a cable connected to the electric enclosure inside the camera;
It is connected to a recorder and used for power supply and signal transmission.

Reference numeral 64 denotes a lens holding tube for connecting the lens system to the structure 31, which is molded with resin and made of plastic mixed with a conductive material, and houses a relay lens tube '56 for holding the imaging lens inside. are doing. The holding cylinder 54 is a screw 55) structure! It is fixed at 11. The relay lens barrel 56 is made of a metal material such as aluminum for accuracy, but since it is fitted with the holding tube 54, it is grounded to the ground of the electric circuit via the holding tube 64 and the structure 61. Therefore, the relay lens barrel 56 does not float relative to the ground of the electrical circuit of the main body. Similarly, the cam 1859 is also attached to the fixed lens barrel 6.
7, but by molding the fixed lens barrel 37 with plastic resin mixed with a conductive material, it is possible to connect the electrical circuit of the camera body through the holding tube 4 through the fitting contact. Ground to the ground. In the same way, the focusing lens holder 40 is also made of aluminum, but the fixed l1A
Since the fixed lens barrel 57 is made of plastic mixed with a conductive material, the focusing lens holder 40 is grounded to the electric circuit inside the main body of the focus lens holder 40, and is suspended relative to the electric circuit. It is grounded without any problem.

As explained above, the imaging optics of the video camera 2 are used to ensure electrical continuity between each part, and to provide the same route effect as when molded with gold material, preventing radio wave noise from entering from the outside and during operation. His role was to remove the Tatsutenoisu created by the humans. In addition, even in a situation where positive bracing parts and metal materials coexist in the photographic lens system, it is in charge of ensuring continuity without lifting all the metal materials from the ground, blocking radio waves from entering from the outside and spreading them all over the area. This is extremely effective in preventing noise from entering.

[Brief explanation of the drawing]

Figure 4 and Figure 2 are cross-sectional views of another example of the structure of the present invention. 51 is the main body of the camera 2, 52 is an image pickup tube, 66 is a cable, 5
4 is a lens holding tube, 55 is a mounting screw, 66 is a relay m tube, 67 is a fixed lens barrel, 6B is a χ-me operation, 59ki cam II, 40 is a focusing lens holder, 41 is a variable magnification lens,
42 represents a correction lens, and 46 represents an operating ring. Applicant Canon Co., Ltd. Agent Gi Marushima -): Yut

Claims (1)

[Claims] A bidet device consisting of an imaging optical system, an imaging device composed of an electric circuit, and a structure enclosing the optical system and the imaging device is molded from a solid plastic material, and a conductive material is applied to the sturdy material. A video camera characterized in that, at the same time as mixing, the structure is grounded in the electrical path.