CN2904508Y

CN2904508Y - Video signal multi-stage connector

Info

Publication number: CN2904508Y
Application number: CN 200620000339
Authority: CN
Inventors: 石崇源
Original assignee: EPIN TECHNOLOGIES Co Ltd
Current assignee: EPIN TECHNOLOGIES Co Ltd
Priority date: 2006-01-10
Filing date: 2006-01-10
Publication date: 2007-05-23
Anticipated expiration: 2016-01-10

Abstract

The utility model relates to a vedio signal multilevel connection device,in particular to a device which can transmit VGA signal to multiple display terminals(referred as VGA splitter).The utility model comprises an input terminal, a cascade output terminal connected with the input terminal and a local output terminal,in which the input terminal is connected with the input terminal of a signal buffer,meanwhile the output terminal of the signal buffer is connected with the local output terminal; the supply terminal of the signal buffer is connected with a supply conversion module.The local output terminal may be multiple and parallel mutually for the purposes of meeting the need of multiple local display terminals,and is corresponded by signal buffers one by one.The utility model obtains vedio signals from main trunk and ensures high-grade image quality,and makes the construction and maintenance more convenient.

Description

The multistage jockey of vision signal

Technical field

The utility model relates to the device of the multistage connection of a kind of vision signal, especially a kind of device that is used for the multistage connection of VGA vision signal in occasions such as video ads, multi-media classroom, exhibition.

Background technology

At present, in occasions such as video ads, multi-media classroom, exhibitions, usually the output of the vision signal of a vision signal source device need be delivered on a plurality of display terminals and shown that each display terminal need show duplicate content, and reach the preferable image quality.

Existing two kinds of devices that are used for the multistage connection of vision signal are realized this purpose, and a kind of is radio frequency (RF) splitter that is used for transmitting radio frequency signal, and it comprises an input terminal, a cascade lead-out terminal and a local lead-out terminal.When using this device, with the transmission of radiofrequency signal, with the cascade step by step of a plurality of RF splitters by coaxial cable.

There is following problem in the radio frequency transmission scheme:

1. the transmission of pure analog quantity, signal is disturbed easily: bigger after " the insertion loss " of splitter adds up step by step, cause the display terminal display effect of level more backward poor more." snowflake interference ", " reticulate pattern ", " black and white rolling " and irregular flicker, black and white pit or " beating " appear easily.

2. can't realize the transmission of high definition quality program: radiofrequency signal itself is with the compound transmission of the component of each demonstration, and display effect is relatively poor, and the resolution that shows as image is lower.When the image resolution ratio of signal source greater than 720 * 576 the time, just can't full backup by radio signal transmission, show as image blurring.

3. need to increase the tuner unit in display terminal image is carried out the demodulation demonstration, overall cost is higher.

Another kind is the VGA distributor that is used to transmit the VGA signal, and it comprises an input terminal and a plurality of local lead-out terminal.By the VGA distributor, one-channel signal there not being the identical signal of demultiplexing under the situation of the loss of signal, is exported to a plurality of display terminals.Adopt " star " topological structure.

Though the scheme of VGA signal distributor has solved the problem of high definition quality program transmission, outstanding picture quality can be provided, and still, the problem that it exists is that wiring is complicated, each display terminal all needs to be connected with the cable of drawing from distributor, and this will increase the cable cost greatly.Particularly, because the VGA signal cable is thicker, will consider passing property and locus in erection process, in some occasion, not having enough spaces can pass for a large amount of cables, makes troubles to construction.

The utility model content

The purpose of this utility model is to provide a kind of multistage jockey of vision signal that is used at the deficiencies in the prior art, by the buffer of high input impedance, realizes that obtaining vision signal from backbone obtains the high quality images quality, and is convenient to construction and maintenance.

For achieving the above object, the utility model provides a kind of vision signal multistage jockey, promptly a kind of the VGA signal is transferred to the device of a plurality of display terminals, is called for short the VGA splitter.It comprises input terminal, cascade lead-out terminal and local lead-out terminal, described cascade lead-out terminal is connected with described input terminal inner straight, wherein: described input terminal also is connected with the input of signal buffer, and the output of this signal buffer is connected with described local lead-out terminal; The power end of described signal buffer is connected with the power conversion module.

In the such scheme, described input terminal, cascade lead-out terminal and local lead-out terminal are equipped with R/G/B analog signal terminal and H/V digital signal terminal; Described signal buffer is R/G/B analog signal buffer and H/V digital signal buffer.

And in order to satisfy the needs of local many display terminals, described local lead-out terminal can be for a plurality of, are connected with independently a R/G/B analog signal buffer and a H/V digital signal buffer between each local lead-out terminal and the described input terminal.Described R/G/B analog signal buffer and described H/V digital signal buffer respectively with described local lead-out terminal in R/G/B analog signal terminal and H/V digital signal terminal corresponding one by one.

R/G/B analog signal buffer and H/V digital signal buffer are high input impedance, make that a plurality of VGA splitters can cascade and very little to the vision signal influence of backbone.

By such scheme, realized obtaining vision signal and having obtained the high quality images quality, and made things convenient for construction and maintenance from backbone.

Below by drawings and Examples, the technical solution of the utility model is described in further detail.

Description of drawings

Fig. 1 has the theory diagram of the multistage jockey of vision signal of a local output for the utility model;

Fig. 2 has the power module circuitry figure of the multistage jockey of vision signal of a local output for the utility model;

Fig. 3 has the working cell circuit diagram of the multistage jockey of vision signal of a local output for the utility model;

Fig. 4 has the application circuit topological diagram of the multistage jockey of vision signal of a local output for the utility model;

Fig. 5 has the theory diagram of the multistage jockey of vision signal of two local outputs for the utility model;

Fig. 6 has the application circuit topological diagram of the multistage jockey of vision signal of two local outputs for the utility model;

Fig. 7 is the distribution schematic diagram of LCD display in the hard-seat coach that can use the multistage jockey of the utility model vision signal.

Embodiment

Fig. 1 has the theory diagram of the VGA splitter of a local output for the utility model, and the VGA splitter comprises:

One signal input part (INPUT) 10: R/G/B analog signal, H/V digital signal from the signal output apparatus of prime is sent here are called the signal on the trunk signal line jointly;

One cascade output (NEXT) 30: this output port with the R/G/B analog signal of signal input, the H/V digital signal is corresponding directly joins, and is used to export the input that is connected to second level splitter, be used to realize cascade so that project installation.

One local output (LOCAL) 20: the signal of input is exported after an analog signal buffer 21 and a digital signal buffer 22 buffered, be used to connect local display terminal.

Analog signal buffer 21 is connected with power conversion module 23 with digital signal buffer 22, this power conversion module 23 is provided with direct current bridge rectifier 231 and two commutator transformers 232, and these rectifier 231 outputs are connected to the input of this DC converter 232.Direct current bridge rectifier 231 and two DC converter 232 mutual group become DC power supply conversion module 23.

Wherein analog signal buffer 21 is made up of for+2 high-speed video analog signal buffer three gains, and Red, Green, three analog signalses of Blue (abbreviation R/G/B) are amplified and drive; Digital signal buffer 22 is made up of two high-speed line digital signal buffers, and two digital switch signals of HSync, VSync (being called for short H/V) are driven.

And analog signal buffer 21 has following characteristic:

1. good consistency: differential gain error＜0.01%, differential phase error＜0.01 °, be used for guaranteeing that the amplification to three components of R/G/B is consistent, make that the color on the display terminal deviation can not occur;

2. high input impedance: input impedance＞10M Ω, have high input impedance, make buffer less to the influence (insertion loss) of backbone signal transmission, make that can " articulate " a plurality of splitters on the circuit is used to drive local display terminal.

The digital signal driver has the characteristic of low input leakage current, input leakage current＜1uA, and this will make driver less to the influence (insertion loss) of backbone signal transmission, be convenient to " articulating " a plurality of splitters equally and be used to drive local display terminal.

Fig. 2 has the power module circuitry figure of the VGA splitter of a local output for the utility model, present embodiment adopts the direct voltage of bridge rectifier input AC point source acquisition+36V, then respectively by two transformer MC 34063 acquisition+5V ,-the 5V direct voltage is buffer power supply, being specially is AD8075 among Fig. 3 and 74HCT244 power supply.In some environment, train for example, for guaranteeing safety, system should adopt the following safe voltage of direct current 36V directly to power for many display terminals.Correspondingly, the VGA splitter input power specification that should adapt to is: input voltage 24～38V.

Fig. 3 has the working cell circuit diagram of the VGA splitter of a local output for the utility model, in the present embodiment, the analog signal buffer adopts chip AD8075, and it includes three analog signal buffers that meet the demands, and the buffering that is respectively applied for the R/G/B signal is amplified.

The digital signal buffer adopts chip 74HCT244, and it includes the digital signal buffering area of 8 passages, with wherein 2 tunnel drivings that are respectively applied for the HSync/VSync signal.

By the VGA splitter that this circuit design goes out, can on 1～20 display terminal, show the digital high-definition video frequency program of identical content simultaneously.Resolution is up to 1920 * 1080.

The input interface of VGA signal requires:

Signal level: analog rgb (VGA) 700mV (pp), the row field synchronization is separated (TTL)

Input impedance: 75 Ω (non-equilibrium);

Row locking range: 30～70KHz;

Field synchronization scope: 56～70Hz;

VGA physical interface form: DB15 Female or other are convenient to the connector terminals of site operation.

The VGA splitter connects the VGA output signal of single channel step by step, by buffer local display terminal is driven to show, can realize that the same screen of 1～20 display terminal shows.Its line topological as shown in Figure 4.The VGA holding wire is responsible for the VGA vision signal 23 of media player 24 outputs is sent on every display terminal 21, and the VGA line length does not wait from 1.5 meters to 20 meters, is linked to each other with display terminal 21 by VGA splitter 22.Last display terminal is directly connected on the backbone.

Fig. 5 has the theory diagram of the VGA splitter of two local outputs for the utility model.Exist in this locality under the situation of the display terminal more than 1, for simplified design, can increase by a cover drive circuit in the VGA splitter 25, promptly increase by one group of analog quantity buffer and set of number amount buffer simultaneously, drive the demonstration of many display terminals in this locality, its line topological as shown in Figure 6.The VGA holding wire is responsible for the VGA vision signal 23 of media player 24 outputs is sent on every display terminal 21, is linked to each other with two display terminals 21 by VGA splitter 25.Last display terminal is directly connected on the backbone.

Especially, this VGA splitter is used for that the same screen of a plurality of displays shows in the compartment of train environment, has received good effect.For example, in soft, carriage with semi-cushioned berth, 9～11 LCD display have been installed, for a plurality of displays are shown with screen,, a VGA splitter is installed in each display back, be used for the local driving that shows, significantly reduced the quantity of cable, be convenient to the installation of system.In the situation of hard seat, as shown in Figure 7, it is to be adjacent to together that two LCD display 11 are arranged, and installs back-to-back, just can adopt the VGA splitter of the local output of two-way, obtains vision signal and obtains the high quality images quality from backbone.

It should be noted last that, above embodiment is only unrestricted in order to the explanation the technical solution of the utility model, although the utility model is had been described in detail with reference to preferred embodiment, those of ordinary skill in the art is to be understood that, can make amendment or be equal to replacement the technical solution of the utility model, and not break away from the spirit and scope of technical solutions of the utility model.

Claims

1, the multistage jockey of a kind of vision signal, comprise input terminal, cascade lead-out terminal and local lead-out terminal, described cascade lead-out terminal is connected with described input terminal inner straight, it is characterized in that: described input terminal also is connected with the input of signal buffer, and the output of this signal buffer is connected with described local lead-out terminal; The power end of described signal buffer is connected with the output of power conversion module.

2, the multistage jockey of vision signal according to claim 1 is characterized in that described input terminal, cascade lead-out terminal and local lead-out terminal are equipped with R/G/B analog signal terminal and H/V digital signal terminal; Described signal buffer is R/G/B analog signal buffer and H/V digital signal buffer.

3, the multistage jockey of vision signal according to claim 1 and 2, it is characterized in that described local lead-out terminal is a plurality of, be connected with independently a R/G/B analog signal buffer and a H/V digital signal buffer between each local lead-out terminal and the described input terminal.

4, the multistage jockey of vision signal according to claim 2 is characterized in that R/G/B analog signal buffer and H/V digital signal buffer are the buffer of high input impedance.