CN202713519U - Building visual intercom system - Google Patents
Building visual intercom system Download PDFInfo
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- CN202713519U CN202713519U CN 201220393134 CN201220393134U CN202713519U CN 202713519 U CN202713519 U CN 202713519U CN 201220393134 CN201220393134 CN 201220393134 CN 201220393134 U CN201220393134 U CN 201220393134U CN 202713519 U CN202713519 U CN 202713519U
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Abstract
The utility model discloses a building visual intercom system, comprising at least 2 building intercom equipment which are interconnected through the a transmission cable, wherein the building intercom equipment are internally or externally provided with video transceiver modules, each video transceiver module is internally provided with a module MCU. The building visual intercom system is characterized in that each video transceiver module is internally provided with a cable length measuring circuit and a video gain compensating circuit, and the cable length measuring circuit and the video gain compensating circuit are connected with the module MCU. The building visual intercom system has the advantages that the video transmission distance is long, the distance of compensation range can be up to 1200 meters, and the intercom system can be used for video compensation of coaxial cable and twisted pair, the image effect is good, the transmission demands of video signals on cables of various lengths can be satisfied, the video gain compensation is free of manual intervention, the engineering debugging difficulty can be greatly reduced, and then the engineering installation and debugging costs can be reduced, meanwhile, the stability of video transmission is guaranteed to the greatest extent.
Description
Technical field
The utility model relates to building visual intercommunication, the relevant safety-security area of video monitoring, particularly a kind of automatic measurement transmission cable length and the automatically storied building visible intercommunication system of adjusting gain compensation.
Background technology
Storied building visible intercommunication system is as the mandatory auxiliary facility of Modern Residence, and the extensive use that the prosperity of real estate develops into building talkback provides a good opportunity.
Yet in the practical application of building visual intercommunication, the long Distance Transmission quality of analog composite video signal (CVBS) is all the time unsatisfactory, becomes a large factor of restriction visible dialogue system universalness.Grow the loss of the amplitude-frequency characteristic of Distance Transmission for remedying vision signal, Video transmission system gain control method in the market is divided into two kinds: a kind of for the fixed gain transmission means, and the shortcoming such as image diffusion during excessively strong, the long transmission distance of vision signal when this mode exists transmission range near; Another kind of adjust compensating gain for gain compensation manually is set by artificial adjustment gain potentiometer or gain toggle switch, there is shortcomings such as need resetting compensating gain after Installation and Debugging complexity, device location adjustment or the transmission cable length adjustment in this mode.
Application number is that 201110317950.3 Chinese utility model patent application discloses " a kind of video transmission method of storied building visible intercommunication system ", main video discharge circuit and the compensating circuit of adopting amplifies with frequency compensation to realize the video automatic gain compensation non-equilibrium vision signal according to cable waste, the applicable cable of this technical scheme is twisted-pair feeder, can not be used for coaxial cable, its transmission range mostly is 1000 meters most, and transmission quality is subjected to the impact of video source, signal amplitude easily.
Summary of the invention
For the problems referred to above, the purpose of this utility model is to provide a kind of storied building visible intercommunication system that also can automatically regulate compensating gain with automatic measurement transmission cable length, it carries out automatic gain compensation according to measured length of cable to vision signal by automatically measuring transmission of video cable length.
For achieving the above object, the technical scheme that the utility model proposes is: a kind of storied building visible intercommunication system, comprise at least 2 building talkback equipment that mutually connect by transmission cable, the internal or external video receiving module of described building talkback equipment, described video receiving module is built-in with module MCU, it is characterized in that: described video receiving module is built-in with the length of cable measuring circuit, the video gain compensating circuit, described length of cable measuring circuit, video gain compensating circuit link to each other with module MCU.
Further, described building talkback equipment also comprises communicating circuit, video circuit, equipment MCU, other assembly circuits, and described video receiving module is built-in with: the module communication circuit: mainly carry out the transmission of communication instruction, control command between the equipment; Video conversion circuit: mainly carry out the transport mode translations of vision signal, as: impedance transformation, balance/non-equilibrium conversion etc.
Further, described cable is coaxial cable or twisted-pair feeder.
Further, described in the utility modelly vision signal is carried out automatic gain compensation comprise the vision signal HFS is carried out pre-lift and post-compensation, the vision signal low frequency part is carried out post-compensation.
The principle that length of cable described in the utility model is measured and video gain compensates is specific as follows.
One, the principle of length of cable measurement
Because there are the characteristics such as resistance loss, dielectric loss, radiation loss and distributed constant (distributed capacitance, distributed inductance) in conventional wire cable (comprising coaxial cable, twisted-pair feeder), when signal transmits in cable, signal power can attenuate when being sent to load from entering cable, and the size of attenuation is relevant with transmission range and signal frequency, transmission range is far away, signal frequency is higher, decay is just larger, such as the swept-frequency signal of accompanying drawing 26MHz shown in the attenuation characteristic of 300 meters coaxial cables.Along with the increase of transmission cable length, distributed constant also can increase, and signal attenuation is larger, and the attenuation characteristic of the signal of same frequency in the transmission medium of same type is consistent, utilizes this characteristic can measure the transmission line distance.Concrete grammar is as follows: during according to the signal f of a certain frequency input Double-strand transmission, the signal f attenuation that transmission length is different is different, in the transmission cable terminal, judge the distance of its transmission according to signal f by the attenuation of transmission cable, also namely learn the length of transmission cable.
Two, video comfort principle
This patent has been abandoned traditional amplifier and has been adopted gain potentiometer or gain toggle switch, and adopted the compensating circuit parameter designing different according to different length of cable Lookup protocols when utilizing above principle design gain compensation circuit.Because the cable of certain-length has different attenuation characteristics to different frequency component in the vision signal, frequency is higher, and it is larger to decay, as shown in Figure 2.The conventional video signals compensating circuit just adopts single gain control that all video signal components are compensated, and can cause like this low frequency component overcompensation of vision signal, and the high fdrequency component undercompensation.Therefore, this patent is taked different gain compensations to the high fdrequency component in the vision signal and low frequency component, to realize recovering preferably the purpose of vision signal.The method of video comfort generally has again two kinds: a kind of is pre-lift, and namely vision signal promotes certain amplitude to the HFS of signal in advance before transmission; Another kind is post-compensation, and namely vision signal is through promoting certain amplitude to the HFS of signal again after the cable transmission.We can find out from Fig. 2, and the HFS decay in the vision signal is very large.If just take separately the method for post-compensation, then can't satisfy so wide dynamic adjustments gain ranging, high-frequency signal will undercompensation so, cause not fogging clear, brightness is dimmed.Therefore, be necessary to take simultaneously the method for pre-lift, amplify in advance for HFS at the vision signal transmitting terminal that the utility model is to utilize simultaneously these two kinds of methods that the vision signal HFS is compensated.
Adopt technique scheme, the video transmission technologies that storied building visible intercommunication system described in the utility model is automatically measured transmission cable length by the length of cable measuring circuit and automatically regulated compensating gain by the video gain compensating circuit is before each transmission video signal, the range measurement circuit all can be measured transmission cable length automatically, then carry out gain compensation according to transmission cable length ride gain compensating circuit, the advantage that has is: the transmission of video distance, the compensation range distance can reach 1200 meters, and the video comfort that can be used for coaxial cable and twisted-pair feeder, image effect is good, can satisfy vision signal in the transmission demand of all lengths cable, and the video gain compensation need not manual intervention, greatly reduce the engineering debug difficulty, and then reduce the project installation and commissioning cost, guaranteed to greatest extent the stability of transmission of video simultaneously.
Description of drawings
Fig. 1 is storied building visible intercommunication system basic block diagram described in the utility model;
Fig. 2 is that the swept-frequency signal of 6MHz is in the attenuation characteristic of 300 meters coaxial cables;
Wherein: 1. the first building talk back equipment, 11. the first video receiving module, 110. the first module communication circuit, 111. the first video conversion circuit, 112. the first cable Length Measuring Circuit, 113. the first video gain compensating circuit, 114. the first module MCU, 12. the first communicating circuit, 13. the first video circuit, 14. the first equipment MCU, 15. first other assembly circuits, 2. the second building talkback equipment, 21. the second video receiving module, 210. the second module communication circuit, 211. the second video conversion circuit, 212. the second length of cable measuring circuit, 213. the second video gain compensating circuit, 214. the second module MCU, 22. the second communicating circuit, 23. the second video circuit, 24. the second equipment MCU, 25. second other assembly circuits, 3. transmission cable.
Embodiment
Below in conjunction with the drawings and specific embodiments, the present invention will be further described.
As shown in Figure 1, a kind of with automatic measurement transmission range and the video transmission technologies that can automatically regulate compensating gain, its typical scenario is that the first building talk back equipment 1 is called out another the second building talkback equipment 2 by transmission cable 3, is described in further detail implementation process below in conjunction with figure one.
Wherein:
The first building talk back equipment 1 built-in (or external) the first video receiving module 11, the first communicating circuit 12, the first video circuit 13, the first equipment MCU 14 and first other assembly circuits 15;
Wherein, have in the first video receiving module 11:
The first module communication circuit 110: mainly carry out the transmission of communication instruction, control command between the equipment;
The first video conversion circuit 111: mainly carry out the conversion of non-equilibrium vision signal and difference video signal;
The first cable Length Measuring Circuit 112: send measuring-signal, detect measuring-signal;
The first video gain compensating circuit 113: vision signal is weighted gain compensation, signal is carried out pre-lift or post-compensation;
The first module MCU114: communication control circuit, transceiving data, calculate the transmission line distance according to distance measurement signals amplitude fading amount, and control video gain compensation rate.
During work:
1) when the first building talk back equipment 1 carried out transmission of video by transmission cable 3 and the second building talkback equipment 2, the first communicating circuit 12, the first module communication circuit 110, the first module communication circuit 210, the second communicating circuit 22 carried out communication and set up video link by host-host protocol;
2) after video link connected, the first cable Length Measuring Circuit 112 in the first video receiving module 11 was transmitted the square-wave test signal loading of certain frequency, certain amplitude in transmission cable 3; The second length of cable measuring circuit 212 in the second video receiving module 21 is measured the test signal amplitude that receives, and the second module MCU 214 is given in transmission; The second module MCU 214 calculates transmission cable length according to test signal amplitude fading amount, afterwards by communication line with the communication of transmission cable length to the first module MCU114;
3) the first module MCU 114 determines the length of transmission cable and controls the first video gain compensating circuit 113 according to the information that receives, realization is carried out pre-lift to the vision signal HFS, and postbacks to the second module MCU 214 by the communications protocol transmission line; Control the second video gain compensating circuit 213 carries out post-compensation to vision signal HFS and low frequency part after the second module MCU 214 reception information;
4) after the compensated video signal amount was determined, the first video conversion circuit 111 carried out the transport mode translations (comprising impedance transformation, balance/non-equilibrium conversion etc.) of vision signal.Video signal transmission to the second video conversion circuit 211, the second video conversion circuits 211 recover receive and output through the vision signal of pattern conversion;
5) the first communicating circuit 12, the first module communication circuit 110, the second module communication circuit 210, the second communicating circuit 22 finish transmission of video by host-host protocol.
Although specifically show and introduced the utility model in conjunction with preferred embodiment; but the those skilled in the art should be understood that; within not breaking away from the spirit and scope of the present utility model that appended claims limits; in the form and details the utility model is made a variety of changes, be protection range of the present utility model.
Claims (5)
1. storied building visible intercommunication system, comprise at least 2 by the interconnective building talkback equipment of transmission cable, the internal or external video receiving module of described building talkback equipment, described video receiving module is built-in with module MCU, it is characterized in that: described video receiving module is built-in with the length of cable measuring circuit, the video gain compensating circuit, described length of cable measuring circuit, video gain compensating circuit link to each other with module MCU.
2. a kind of storied building visible intercommunication system according to claim 1, it is characterized in that: described building talkback equipment also comprises communicating circuit, video circuit, equipment MCU.
3. a kind of storied building visible intercommunication system according to claim 1, it is characterized in that: described video receiving module is built-in with: module communication circuit and video conversion circuit.
4. a kind of storied building visible intercommunication system according to claim 1, it is characterized in that: described cable is coaxial cable.
5. a kind of storied building visible intercommunication system according to claim 1, it is characterized in that: described cable is twisted-pair feeder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220393134 CN202713519U (en) | 2012-08-09 | 2012-08-09 | Building visual intercom system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201220393134 CN202713519U (en) | 2012-08-09 | 2012-08-09 | Building visual intercom system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202713519U true CN202713519U (en) | 2013-01-30 |
Family
ID=47593773
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201220393134 Expired - Lifetime CN202713519U (en) | 2012-08-09 | 2012-08-09 | Building visual intercom system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN202713519U (en) |
-
2012
- 2012-08-09 CN CN 201220393134 patent/CN202713519U/en not_active Expired - Lifetime
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: Five, building 2, building 361000 Fujian Xinglian Electronic City Xiamen Province torch torch high tech Zone Innovation Park Road Patentee after: XIAMEN DNAKE INTELLIGENT TECHNOLOGY CO.,LTD. Address before: Five, building 2, building 361000 Fujian Xinglian Electronic City Xiamen Province torch torch high tech Zone Innovation Park Road Patentee before: XINGTEL SECURITY XIAMEN Co.,Ltd. |
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| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20130130 |