CN2664126Y

CN2664126Y - A novel video transmission cable

Info

Publication number: CN2664126Y
Application number: CN 200320121020
Authority: CN
Inventors: 李基生
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-11-27
Filing date: 2003-11-27
Publication date: 2004-12-15
Anticipated expiration: 2013-11-27

Abstract

The utility model discloses a video transmission cable with double-insulation and double-shielded structure which comprises an inner conductor (1), the outside of which is provided with a insulating layer (2) which provided outside with a shielding layer (8). The cable is characterized in that: the outside of the shielding layer (8) is provided with the insulating layer (5); the outside of the insulating layer (5) is provided with the shielding layer (6) which is provided outside with an outer protection sheathing to form a coaxial-cable with two electric insulating layers and two electric shielding layers structure; the coaxial-cable is a coaxial-cable which can effectively resist the interference of the external potential loop and the external space electromagnetism.

Description

A kind of novel video transmission cable

(1) technical field:

The utility model relates to the transmission line technology field, is the coaxial cable of a kind of two insulation, double shield structure specifically.

(2) background technology:

At present, a large amount of video transmission coaxial cables that use, transmission range coaxial cable far away in the TV monitor system engineering particularly, its electrical structure all are made of coaxial inner conductor heart yearn, insulating barrier, conductive shielding layer and four essential parts of oversheath from inside to outside; On actual design and process structure, conductive shielding layer has one deck, two-layer, the conductive layer of different structures such as three layers or four layers is formed, but the conductive shielding layer that these are different, on electrical equipment, remain a conductive shielding layer of mutual conduction, four essential parts constitute so still belong to, present widely used a kind of typical case " four shieldings " structure coaxial cable, it comprises inner wire (heart yearn), first insulating barrier (is the standard insulating barrier of coaxial cable, core polyethylene strictly according to the facts, lotus root core polyethylene, insulating material such as physical blowing polyethylene), the aluminium foil conductive shielding layer, metal knitted net screen, second foil shielding layer, the second metal knitted net screen, oversheath, aluminium foil conductive shielding layer wherein, metal knitted net screen, second foil shielding layer, four screen mutual conduction of the second metal knitted net screen, on the electrical equipment conductive shielding layer, so still belong to the coaxial cable of forming by four essential parts.In actual signal transmission system circuit, inner conductor and conductive shielding layer have been formed signal transmission closed-loop path jointly.When in than the environment of strong electromagnetic, using this cable, on the cable outer shielding layer, be easy to induce disturbance current, form and disturb electromotive force, thereby in the video signal transmission closed-loop path, form interference signal, this interference signal increases along with the lengthening of cable, this is the problem that often runs into during engineering is used, equally, in the engineering of long cable is used, because the coaxial cable outer shielding layer is two-terminal-grounding normally, when the epd at two ends is big, also can on the cable outer shielding layer, produce loop earth potential disturbance current and induced electromotive force, the interference signal that formation is difficult to get rid of.

(3) summary of the invention:

The purpose of this utility model is intended to overcome the deficiency of above-mentioned prior art, and the coaxial cable of a kind of two insulation, double shield structure is provided, mainly solved cable in engineering is used, easily produced the problem of interference signal when in having, easily producing interference signal and current potential loop interference externally than the environment of strong electromagnetic.

In order to achieve the above object, the utility model is achieved in that a kind of novel video transmission cable, it comprises inner wire 1, inner wire 1 peripheral hardware insulating barrier 2, insulating barrier 2 outer provided with shielding layer 8, its special character are that provided with shielding layer 6 outside insulating barrier 5 at screen 8 peripheral hardware insulating barriers 5, screen 6 peripheral hardware oversheaths 7 form the coaxial cable of two electric insulation layers and two electric shield layer structures.

In order further to realize above-mentioned purpose, a kind of novel video transmission cable of the present utility model, its described screen 6 and screen 8 are made up of the conductive layer of one deck or two-layer above mutual conduction; The electric insulation layer that described insulating barrier 5 can be made up of different materials, different-thickness, the different insulative number of plies.

Compared with the prior art a kind of novel video transmission cable described in the utility model has following good effect: because video transmission cable of the present utility model has two insulating barriers and two screens, thereby be used for vision signal remote transmission engineering, be highly resistant to current potential loop interference externally and space outerpace electromagnetic interference.

(4) description of drawings:

Fig. 1---structural representation of the present utility model;

Another structural representation of Fig. 2---utility model.

(5) embodiment:

In order to understand better and to implement, provide its body embodiment below in conjunction with accompanying drawing and describe a kind of novel video transmission cable of the utility model in detail.

Embodiment 1, referring to Fig. 1, adopt coaxial inner conductor 1 (heart yearn), on its excircle, process insulating barrier 2 with extruder, insulating barrier 2 is standard insulating barriers of coaxial cable, can adopt insulating material such as core polyethylene, lotus root core polyethylene, physical blowing polyethylene strictly according to the facts, on insulating barrier 2 excircles, process screen 8, insulating barrier 5, screen 6, oversheath 7 successively, screen 8 and screen 6 adopt metal knitted net screen respectively, insulating barrier 5 is a thin dielectric film, can form an electric insulation layer by different materials, different-thickness, the different insulative number of plies.

Embodiment 2, and referring to Fig. 2, with embodiment 1, difference is that screen 8 is made up of one deck foil shielding layer 3 and layer of metal mesh grid screen 4.

A kind of novel video transmission cable described in the utility model, be used for vision signal remote transmission engineering, outside electromagnetic interference, can only on outer screen, produce induced current and induced electromotive force, for the external disturbance electromagnetic field, in the inner space of cable outer layer screen the inside, then be an equivalent potential screen space that does not have interfere with electromagnetic field.Because vision signal is formed the transmission closed-loop path by inner wire and internal layer screen, they all are in this glitch-free shielding space, so can not form disturbance current and electromotive force on the internal layer screen; Owing to insulate between the interior outer shielding layer, the disturbance current that produces on the outer screen can not be transmitted to the internal layer screen yet and form the interference electromotive force again, so just can not produce interference in vision signal actual transmissions closed-loop path yet.Equally, disturb for the loop earth potential, even outer field screen two ends are ground connection all, can only on outer field screen, produce at most and disturb electromotive force, because the buffer action of outer insulation, this interference electromotive force does not constitute the closed-loop path with the internal layer screen, so can not produce interference in vision signal actual transmissions closed-loop path yet.Thereby the utility model is being used for vision signal remote transmission engineering, can effectively resist externally the current potential loop and disturb and the space outerpace electromagnetic interference.

A kind of novel video transmission cable described in the utility model, the coaxial cable structure that its inner wire 1, insulating barrier 2, internal layer screen 8 formed is applicable to the coaxial cable of different qualities impedance.

Claims

1, a kind of novel video transmission cable, it comprises inner wire (1), inner wire (1) peripheral hardware insulating barrier (2), the outer provided with shielding layer of insulating barrier (2) (8), it is characterized in that at screen (8) peripheral hardware insulating barrier (5), provided with shielding layer (6) outside insulating barrier (5), screen (6) peripheral hardware oversheath (7) forms the coaxial cable of two electric insulation layers and two electric shield layer structures.

2, by the described a kind of novel video transmission cable of claim 1, it is characterized in that described screen (6) and screen (8) by one deck or two-layer more than the conductive layer of mutual conduction form.

3,, it is characterized in that the electric insulation layer that described insulating barrier (5) can be made up of different materials, different-thickness, the different insulative number of plies by claim 1 or 2 described a kind of novel video transmission cables.