Anti-interference television system bidirectional user port capable of preventing creepage

Abstract

The invention discloses an anti-interference and creepage protective television system two-way user port which comprises an integral metallic shield casing, a circuit board, an input port and an output port arranged in the casing, wherein signal poles for connection with a coaxial signal cable and shaded poles for connection with a coaxial shield cable are arranged on both the input port and the output port, and the shaded poles of the input port respectively enter the casing through holes in the casing without communication with the casing and are isolated from the signal poles in a non-capacitance mode. The invention which not only meets the requirements of a digital TV but also is compatible with an analog TV has reliable and definite anti-interference and creepage protective functions which exist even in case of TV and set-top box circuit abnormality. In whatever cable TV networks of a digital TV system or an analog TV system, the invention can overcome the defects of the prior art and ensure the personnel safety of the user and excellent visual effect.

Description

Technical field: [0001] The invention relates to a connection device for television signals, in particular to a bidirectional user port for digital television signals. Background technique: [0002] Subscriber ports used in existing cable television reception systems, including digital television reception systems, whether unidirectional or bidirectional, regardless of the number of input ports and output ports, and whether standard F-type connectors or Other improved plug-in devices generally have the following common problems: 1. The input shielding wire of the coaxial cable is connected with the metal shielding shell of the user port. When the signal line or signal pole is passed in, the capacitor will not be able to isolate the electricity, so that the shell of the user port will be charged, and the electricity on the shell will be conducted to the TV or set-top box through the shielded wire of the output port of the user port to charge the TV or set-top box. At the sam...

AI Technical Summary

Problems solved by technology

[0002] Subscriber ports used in existing cable television reception systems, including digital television reception systems, whether unidirectional or bidirectional, regardless of the number of input ports and output ports, and whether standard F-type connectors or Other improved plug-in devices generally have the following common problems: 1. The input shielding wire of the coaxial cable is connected with the metal shielding shell of the user port. When the signal line or signal pole is passed in, the capacitor will not be able to isolate the electricity, so that the shell of the user port will be charged, and the electricity on the shell will be conducted to the TV or set-top box through the shielded wire of the output port of the user port to charge the TV or set-top box. At the same time, the electricity on the casing enters the entire network system through the shielded wire of the input port of the user port, so that all shielded wires, all user ports and all TV sets or set-top boxes of the same network system are charged, so that the entire TV network becomes The real power grid will be endangered, which will endanger the lives of all users and related workers (such as network maintenance personnel)

In addition, since the shielded wire is electrified, it will not be shielded, and various radio waves (such as broadcast waves, wireless TV waves, wireless communication waves), clutter generated by industrial appliances and household appliances, etc., will be strung together. Cable TV system, and superimposition or amplification in the system will cause interference to users of the entire system; 2. The connection is not firm, the connector is embroidered, which is equivalent to connecting a resistor and a frequency mixing diode, and poor contact will also generate noise and interference—distortion of public roads, which degrades the signal-to-noise ratio of the TV screen, resulting in snowflakes, black bars, and images moving up and down, left and right. screen window, and even frequent mosaics, static frames, bit errors, signal interruptions, failure to receive images, etc.

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