CN109120882A - Video-conference phone system - Google Patents
Video-conference phone system Download PDFInfo
- Publication number
- CN109120882A CN109120882A CN201811212286.4A CN201811212286A CN109120882A CN 109120882 A CN109120882 A CN 109120882A CN 201811212286 A CN201811212286 A CN 201811212286A CN 109120882 A CN109120882 A CN 109120882A
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- Prior art keywords
- module
- video
- capacitor
- triode
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Classifications
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/14—Systems for two-way working
- H04N7/15—Conference systems
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/14—Systems for two-way working
- H04N7/141—Systems for two-way working between two video terminals, e.g. videophone
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N7/00—Television systems
- H04N7/14—Systems for two-way working
- H04N7/141—Systems for two-way working between two video terminals, e.g. videophone
- H04N7/142—Constructional details of the terminal equipment, e.g. arrangements of the camera and the display
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- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Rectifiers (AREA)
Abstract
The invention discloses a kind of video-conference phone systems, including audio-frequency module, video module, audio-video processing module, wireless communication module, microprocessor, display and power supply module, audio-frequency module and video module are connect with audio-video processing module, and microprocessor is connect with audio-frequency module, video module, display and power supply module respectively；Power supply module includes voltage input end, transformer, bridge rectifier, first capacitor, the first triode, second resistance, third capacitor, the second triode, first diode, the first potentiometer, the second capacitor and voltage output end, one end of the primary coil of transformer and one end of voltage input end connect, the other end of the secondary coil of transformer and the other end of voltage input end connect, and one end of the secondary coil of transformer and an input terminal of bridge rectifier connect.Circuit structure of the present invention is relatively simple, cost is relatively low, maintain easily, the safety and reliability of circuit is higher.
Description
Technical field
The present invention relates to video conference field, in particular to a kind of video-conference phone system.
Background technique
Video conferencing system, also known as TV conference system, this refers to the individual or group of two or more different places
Body, by sound, image and document data mutual transmission, realizes the communication immediately and interacted by transmission line and multimedia equipment, with
Realize the system equipment of teleconference.The use of video conference is somewhat like phone, in addition to that can see the people to converse with you and progress
Outside communication, moreover it is possible to which the expression and movement for seeing them make the people in different places just as linking up in same meeting room.
The component that the power pack of traditional video conference system uses is more, and circuit structure is complicated, and hardware cost is higher, it has not been convenient to tie up
Shield.In addition, since the power pack of traditional video conference system lacks corresponding circuit protection function, such as: current-limiting protection function
Can and signal interference function be prevented, causes the safety and reliability of circuit poor.
Summary of the invention
The technical problem to be solved in the present invention is that in view of the above drawbacks of the prior art, provide a kind of circuit structure compared with
For simple, cost is relatively low, maintains easily, the higher video-conference phone system of the safety and reliability of circuit.
The technical solution adopted by the present invention to solve the technical problems is: a kind of video-conference phone system is constructed, including
Audio-frequency module, video module, audio-video processing module, wireless communication module, microprocessor, display and power supply module, it is described
Audio-frequency module and video module are connect with the audio-video processing module, the audio-video processing module and the wireless communication
Module connection, the microprocessor are connect with the audio-frequency module, video module, display and power supply module respectively, the sound
Video processing module includes audio processing modules and video processing module, the audio processing modules respectively with the audio-frequency module
It is connected with wireless communication module, the video processing module is connect with the video module and wireless communication module respectively；
The power supply module includes voltage input end, transformer, bridge rectifier, first capacitor, the first triode, second
Resistance, third capacitor, the second triode, first diode, the first potentiometer, the second capacitor and voltage output end, the transformation
One end of the primary coil of device is connect with one end of the voltage input end, the other end of the secondary coil of the transformer and institute
State the other end connection of voltage input end, an input of one end of the secondary coil of the transformer and the bridge rectifier
End connection, another input terminal of the bridge rectifier are connect with the other end of the secondary coil of the transformer, the bridge
One output end of formula rectifier respectively with the collector of first triode, the cathode of first capacitor and third capacitor one
End connection, the base stage of the plus earth of the first capacitor, first triode are connect with one end of the second resistance, institute
State the other end ground connection of second resistance, the emitter of first triode respectively with the collector of second triode, the
The other end of three capacitors, a fixing end of the first potentiometer, the cathode of the second capacitor are connected with the cathode of voltage output end, institute
The emitter for stating the second triode is connect with the cathode of the first diode, the base stage of second triode and described first
One sliding end of potentiometer connects, the anode of the first diode, another fixing end of the first potentiometer, the second capacitor
Anode and the anode of voltage output end be grounded, the resistance value of the second resistance is 28k Ω, the capacitance of the third capacitor
For 340pF.
In video-conference phone system of the present invention, the power supply module further includes the 4th capacitor, and the described 4th
One end of capacitor is connect with the emitter of first triode, the other end and second triode of the 4th capacitor
Collector connection, the capacitance of the 4th capacitor are 430pF.
In video-conference phone system of the present invention, the power supply module further includes the second diode, and described
The anode of two diodes is connect with the emitter of first triode, the cathode of second diode and the voltage output
The cathode at end connects, the model L-1822 of second diode.
In video-conference phone system of the present invention, the power supply module further includes 3rd resistor, the third
One end of resistance is connect with another input terminal of the bridge rectifier, the other end of the 3rd resistor and the transformer
Secondary coil other end connection, the resistance value of the 3rd resistor is 36k Ω.
In video-conference phone system of the present invention, first triode and the second triode are positive-negative-positive
Triode.
In video-conference phone system of the present invention, the wireless communication module be bluetooth module, WIFI module,
Gsm module, GPRS module, CDMA module, CDMA2000 module, WCDMA module, TD-SCDMA module, Zigbee module or
LoRa module.
Implement video-conference phone system of the invention, has the advantages that due to being equipped with audio-frequency module, video screen module
Block, audio-video processing module, wireless communication module, microprocessor, display and power supply module；Power supply module includes voltage input
End, transformer, bridge rectifier, first capacitor, the first triode, second resistance, third capacitor, the second triode, the one or two
Pole pipe, the first potentiometer, the second capacitor and voltage output end, power supply of the power supply module relative to traditional video conference system
Point, the component used is less, due to saving some components, hardware cost can be reduced in this way, in addition, second resistance
Current-limiting protection is carried out for the base current to the first triode, third capacitor is for preventing the first triode and the second triode
Between interference, therefore circuit structure is relatively simple, cost is relatively low, maintain easily, the safety and reliability of circuit is higher.
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below
There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this
Some embodiments of invention for those of ordinary skill in the art without creative efforts, can be with
It obtains other drawings based on these drawings.
Fig. 1 is the structural schematic diagram in video-conference phone system one embodiment of the present invention；
Fig. 2 is the circuit diagram of power supply module in the embodiment.
Specific embodiment
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete
Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on
Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts every other
Embodiment shall fall within the protection scope of the present invention.
In video-conference phone system embodiment of the present invention, the structural schematic diagram of the video-conference phone system such as Fig. 1
It is shown.In Fig. 1, which includes audio-frequency module 1, video module 2, audio-video processing module 3, wireless communication
Module 4, microprocessor 5, display 6 and power supply module 7, wherein audio-frequency module 1 and video module 2 handle mould with audio-video
Block 3 connects, and audio-video processing module 3 connect with wireless communication module 4, microprocessor 5 respectively with audio-frequency module 1, video module
2, display 6 and power supply module 7 connect, and audio-video processing module 3 includes audio processing modules 31 and video processing module 32, sound
Frequency processing module 31 is connect with audio-frequency module 1 and wireless communication module 4 respectively, video processing module 3 respectively with video module 2 and
Wireless communication module 4 connects.
Audio-frequency module 1 includes microphone and loudspeaker (not shown), microphone and loudspeaker with audio-video processing module 3
Connection.Microphone is used to obtain the sound of video-conference phone position, and the sound that will acquire is converted to electric signal.Wheat
Gram wind can be dynamic microphones, Electret Condencer Microphone, electret condenser microphone, micro-electro-mechanical microphone, aluminium band type Mike
Wind, carbon microphone etc., can according to need in specific select and specific application scenarios are flexibly selected.Loudspeaker
Namely loudspeaker, for playing sound, the voice signal that will acquire is converted to sound and plays back.Loudspeaker can be electricity
Loudspeaker, electromagnetic loudspeaker, piezo-electric loudspeaker, electric pole type loudspeaker or plasma speaker etc. are specifically selecting
Used time can according to need and specific application scenarios are flexibly selected.
In the present embodiment, audio-frequency module 1 is connected by audio processing modules 31, may be implemented to the sound in audio-frequency module 1
Sound or voice signal are handled, and connect video module 2 by video processing module 32, can video figure to video module 2
Picture or video image data are handled.
Video module 2 includes camera (not shown), passes through the available neighbouring video data of camera, example
Such as: when carrying out meeting, there are four the branch companies of distance apart from each other to have a meeting, after getting video data, in the case, respectively
As soon as a branch company location can prevent the video-conference phone system, the camera in the video-conference phone system
The available video data to around place.Camera can be CMOS camera or CCD camera, can be by article institute
The light of reflection is converted to digital signal, is stored in memory after compression.
In the present embodiment, it can be convenient by microprocessor 5 and audio-frequency module 1 and video module 2 controlled, such as:
Height-regulating volume can be executed, volume is turned down, opens or closes operation.
The video-conference phone system shows video image, and the video council by setting display 6, by display 6
View telephone system also can be carried out the input and output of sound and the acquisition of video image data, so as to realize meeting well
View is linked up.The video-conference phone system can smoothly realize communication, even if the people for participating in linking up is distributed in different regions,
It can effectively realize communication.
Wireless communication module 4 can transmit the video of generation and audio data, be also used to will acquire and need to transmit
To the video and audio data of the video-conference phone system.
In the present embodiment, wireless communication module 4 is bluetooth module, WIFI module, gsm module, GPRS module, CDMA mould
Block, CDMA2000 module, WCDMA module, TD-SCDMA module, Zigbee module or LoRa module.It is a variety of wireless by being arranged
Communication mode can not only increase the flexibility of communication, moreover it is possible to meet the needs of different user and different occasions.Especially
When it is using LoRa module, farther out, and communication performance is relatively stable, is suitable for higher to QoS requirement for communication distance
Occasion.
Fig. 2 is the circuit diagram of power supply module in the present embodiment, and in Fig. 2, which includes voltage input end
Vin, transformer T, bridge rectifier Z, first capacitor C1, the first triode Q1, second resistance R2, third capacitor C3, the two or three
Pole pipe Q2, first diode D1, the first potentiometer RP1, the second capacitor C2 and voltage output end Vo, the primary coil of transformer T
One end connect with one end of voltage input end Vo, the other end of the secondary coil of transformer T is another with voltage input end Vin's
End connection, one end of the secondary coil of transformer T are connect with an input terminal of bridge rectifier Z, and bridge rectifier Z's is another
A input terminal is connect with the other end of the secondary coil of transformer T, an output end of bridge rectifier Z respectively with the one or three pole
The collector of pipe Q1, the cathode of first capacitor C1 are connected with one end of third capacitor C3, the plus earth of first capacitor C1, and first
The base stage of triode Q1 is connect with one end of second resistance R2, the other end ground connection of second resistance R2, the hair of the first triode Q1
Emitter-base bandgap grading respectively with the collector of the second triode Q2, the other end of third capacitor C3, the first potentiometer RP1 a fixing end,
The cathode of second capacitor C2 is connected with the cathode of voltage output end Vo, and the emitter of the second triode Q2 is with first diode D1's
Cathode connection, the base stage of the second triode Q2 are connect with a sliding end of the first potentiometer RP1, the sun of first diode D1
Pole, another fixing end of the first potentiometer RP1, the anode of the second capacitor C2 and the positive of voltage output end Vo are grounded.
The power pack of the power supply module 7 relative to traditional video conference system, the component used is less, circuit knot
Structure is relatively simple, maintains easily, and due to saving some components, can reduce hardware cost in this way.In addition, second resistance R2
For Current Limiting Diodes, current-limiting protection is carried out for the base current to the first triode Q1, third capacitor C3 is coupled capacitor, is used
In preventing the interference between the first triode Q1 and the second triode Q2, therefore the safety and reliability of circuit is higher.It is worth
One is mentioned that, in the present embodiment, the resistance value of second resistance R2 is 28k Ω, and the capacitance of third capacitor C3 is 340pF, certainly,
In practical application, the resistance value of second resistance R2 and the capacitance of third capacitor C3 can be adjusted accordingly as the case may be
It is whole, that is, the resistance value of second resistance R2 and the capacitance of third capacitor C3 can be increased accordingly as the case may be or
Reduce.
The working principle of the power supply module 7 is as follows: bridge rectifier Z exports the direct current of an amplitude variation by transformation
Voltage, the voltage are added on the collector of the first triode Q1, in the case where guaranteeing the first triode Q1 conducting, the voltage
As the voltage output value of voltage output end Vo, while the second triode Q2 is by being connected to the first potentiometer RP1 of its base stage
Variation control the second triode Q2, and by the Voltage Feedback on the emitter of second triode Q2 give the first triode Q1,
Achieve the purpose that pressure stabilizing to offset the fluctuation of output voltage.
In the present embodiment, the first triode Q1 and the second triode Q2 are PNP type triode.The power supply module 7 uses
PNP type triode, while first capacitor C1 is polar capacitor, it is ensured that one stable negative value DC voltage of output.
In the present embodiment, which further includes the 4th capacitor C4, one end of the 4th capacitor C4 and the first triode Q1
Emitter connection, the other end of the 4th capacitor C4 connect with the collector of the second triode Q2.4th capacitor C4 is coupling electricity
Hold, for preventing the interference between the first triode Q1 and the second triode Q2, with further enhance circuit safety and can
By property.It is noted that the capacitance of the 4th capacitor C4 is 430pF in the present embodiment, certainly, in practical applications, the 4th
The capacitance of capacitor C4 can adjust accordingly as the case may be, that is, the capacitance of the 4th capacitor C4 can be according to tool
Body situation is increased accordingly or is reduced.
In the present embodiment, which further includes the second diode D2, the anode of the second diode D2 and the one or three pole
The emitter of pipe Q1 connects, and the cathode of the second diode D2 is connect with the cathode of voltage output end Vo.Second diode D2 is limited
Diode is flowed, current-limiting protection is carried out for the emitter current to the first triode Q1, further to enhance the safety of circuit
Property and reliability.It is noted that in the present embodiment, the model L-1822 of the second diode D2, certainly, in practical application
In, the second diode D2 can also have the diode of similar functions using other models.
In the present embodiment, which further includes 3rd resistor R3, one end of 3rd resistor R3 and bridge rectifier Z
The connection of another input terminal, the other end of 3rd resistor R3 connect with the other end of the secondary coil of transformer T.3rd resistor
R3 is current-limiting resistance, for carrying out current-limiting protection, to further enhance current limitation effect.It is noted that in the present embodiment, the
The resistance value of three resistance R3 is 36k Ω, and certainly, in practical applications, the resistance value of 3rd resistor R3 can carry out as the case may be
Corresponding adjustment, that is, the resistance value of 3rd resistor R3 can be increased accordingly or be reduced as the case may be.
In short, in the present embodiment, which is used
Component is less, and circuit structure is relatively simple, maintains easily, due to saving some components, can reduce in this way hardware at
This.In addition, being equipped with current-limiting resistance and coupled capacitor in the power supply module 7, therefore the safety and reliability of circuit is higher.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in essence of the invention
Within mind and principle, any modification, equivalent replacement, improvement and so on be should all be included in the protection scope of the present invention.
Claims (6)
1. a kind of video-conference phone system, which is characterized in that including audio-frequency module, video module, audio-video processing module, nothing
Line communication module, microprocessor, display and power supply module, the audio-frequency module and video module are handled with the audio-video
Module connection, the audio-video processing module connect with the wireless communication module, the microprocessor respectively with the audio
Module, video module, display are connected with power supply module, and the audio-video processing module includes at audio processing modules and video
Module is managed, the audio processing modules are connect with the audio-frequency module and wireless communication module respectively, the video processing module
It is connect respectively with the video module and wireless communication module；
The power supply module includes voltage input end, transformer, bridge rectifier, first capacitor, the first triode, the second electricity
Resistance, third capacitor, the second triode, first diode, the first potentiometer, the second capacitor and voltage output end, the transformer
One end of primary coil connect with one end of the voltage input end, the other end of the secondary coil of the transformer with it is described
The other end of voltage input end connects, an input terminal of one end of the secondary coil of the transformer and the bridge rectifier
Connection, another input terminal of the bridge rectifier are connect with the other end of the secondary coil of the transformer, the bridge-type
One output end of rectifier one end with the collector of first triode, the cathode of first capacitor and third capacitor respectively
Connection, the base stage of the plus earth of the first capacitor, first triode is connect with one end of the second resistance, described
The other end of second resistance is grounded, the emitter of first triode respectively with the collector of second triode, third
The other end of capacitor, a fixing end of the first potentiometer, the cathode of the second capacitor are connected with the cathode of voltage output end, described
The emitter of second triode is connect with the cathode of the first diode, the base stage of second triode and first electricity
The sliding end connection of position device, the anode of the first diode, another fixing end of the first potentiometer, the second capacitor
The anode of anode and voltage output end is grounded, and the resistance value of the second resistance is 28k Ω, and the capacitance of the third capacitor is
340pF。
2. video-conference phone system according to claim 1, which is characterized in that the power supply module further includes the 4th electricity
Hold, one end of the 4th capacitor connect with the emitter of first triode, the other end of the 4th capacitor with it is described
The collector of second triode connects, and the capacitance of the 4th capacitor is 430pF.
3. video-conference phone system according to claim 2, which is characterized in that the power supply module further includes the two or two
Pole pipe, the anode of second diode are connect with the emitter of first triode, the cathode of second diode with
The cathode of the voltage output end connects, the model L-1822 of second diode.
4. video-conference phone system according to claim 3, which is characterized in that the power supply module further includes third electricity
Resistance, one end of the 3rd resistor are connect with another input terminal of the bridge rectifier, the other end of the 3rd resistor
It is connect with the other end of the secondary coil of the transformer, the resistance value of the 3rd resistor is 36k Ω.
5. video-conference phone system according to any one of claims 1 to 4, which is characterized in that the one or three pole
Pipe and the second triode are PNP type triode.
6. video-conference phone system according to any one of claims 1 to 4, which is characterized in that the wireless communication
Module is bluetooth module, WIFI module, gsm module, GPRS module, CDMA module, CDMA2000 module, WCDMA module, TD-
SCDMA module, Zigbee module or LoRa module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811212286.4A CN109120882A (en) | 2018-10-09 | 2018-10-09 | Video-conference phone system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811212286.4A CN109120882A (en) | 2018-10-09 | 2018-10-09 | Video-conference phone system |
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| Publication Number | Publication Date |
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| CN109120882A true CN109120882A (en) | 2019-01-01 |
Family
ID=64855034
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811212286.4A Pending CN109120882A (en) | 2018-10-09 | 2018-10-09 | Video-conference phone system |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022139894A1 (en) * | 2020-12-21 | 2022-06-30 | Arris Enterprises Llc | Providing synchronization for video conference audio and video |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6076853A (en) * | 1983-10-01 | 1985-05-01 | Nippon Telegr & Teleph Corp <Ntt> | Switch control circuit for telephone circuit |
| US20030223160A1 (en) * | 2002-05-31 | 2003-12-04 | Henry Pixley | Ground fault circuit interrupter for coaxial drop cable and method of operation |
| CN203827453U (en) * | 2013-11-29 | 2014-09-10 | 广州华工信元通信技术有限公司 | Video conference system |
| CN206226309U (en) * | 2016-11-17 | 2017-06-06 | 王旋 | A kind of low-power power regulation device |
| CN206878738U (en) * | 2017-04-18 | 2018-01-12 | 鄂尔多斯职业学院 | A kind of motor controller |
| CN207052228U (en) * | 2017-07-20 | 2018-02-27 | 宁夏瑞博云电系统技术有限公司 | A kind of convenience-for-people information system of electric power |
| CN207560201U (en) * | 2017-12-20 | 2018-06-29 | 厦门优数科技有限公司 | A kind of net meeting system |
| CN207625682U (en) * | 2017-12-27 | 2018-07-17 | 珠海市德宇辉煌信息科技有限公司 | Video monitoring equipment |
| CN207851026U (en) * | 2018-01-31 | 2018-09-11 | 珠海市中科领航科技有限公司 | Systematic gas monitoring system |
-
2018
- 2018-10-09 CN CN201811212286.4A patent/CN109120882A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6076853A (en) * | 1983-10-01 | 1985-05-01 | Nippon Telegr & Teleph Corp <Ntt> | Switch control circuit for telephone circuit |
| US20030223160A1 (en) * | 2002-05-31 | 2003-12-04 | Henry Pixley | Ground fault circuit interrupter for coaxial drop cable and method of operation |
| CN203827453U (en) * | 2013-11-29 | 2014-09-10 | 广州华工信元通信技术有限公司 | Video conference system |
| CN206226309U (en) * | 2016-11-17 | 2017-06-06 | 王旋 | A kind of low-power power regulation device |
| CN206878738U (en) * | 2017-04-18 | 2018-01-12 | 鄂尔多斯职业学院 | A kind of motor controller |
| CN207052228U (en) * | 2017-07-20 | 2018-02-27 | 宁夏瑞博云电系统技术有限公司 | A kind of convenience-for-people information system of electric power |
| CN207560201U (en) * | 2017-12-20 | 2018-06-29 | 厦门优数科技有限公司 | A kind of net meeting system |
| CN207625682U (en) * | 2017-12-27 | 2018-07-17 | 珠海市德宇辉煌信息科技有限公司 | Video monitoring equipment |
| CN207851026U (en) * | 2018-01-31 | 2018-09-11 | 珠海市中科领航科技有限公司 | Systematic gas monitoring system |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2022139894A1 (en) * | 2020-12-21 | 2022-06-30 | Arris Enterprises Llc | Providing synchronization for video conference audio and video |
| US11522929B2 (en) | 2020-12-21 | 2022-12-06 | Arris Enterprises Llc | Providing synchronization for video conference audio and video |
| US11824908B2 (en) | 2020-12-21 | 2023-11-21 | Arris Enterprises Llc | Providing synchronization for video conference audio and video |
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