GB2374226A - Automatic audio-video output circuit - Google Patents

Automatic audio-video output circuit Download PDF

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Publication number
GB2374226A
GB2374226A GB0108377A GB0108377A GB2374226A GB 2374226 A GB2374226 A GB 2374226A GB 0108377 A GB0108377 A GB 0108377A GB 0108377 A GB0108377 A GB 0108377A GB 2374226 A GB2374226 A GB 2374226A
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GB
United Kingdom
Prior art keywords
video
audio
signal
signal output
terminals
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB0108377A
Other versions
GB0108377D0 (en
Inventor
Chin-Chi Ho
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JOIN COMP CO Ltd
JOIN Computer Co Ltd
Original Assignee
JOIN COMP CO Ltd
JOIN Computer Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by JOIN COMP CO Ltd, JOIN Computer Co Ltd filed Critical JOIN COMP CO Ltd
Priority to GB0108377A priority Critical patent/GB2374226A/en
Publication of GB0108377D0 publication Critical patent/GB0108377D0/en
Publication of GB2374226A publication Critical patent/GB2374226A/en
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
    • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
    • H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
    • H04N21/436—Interfacing a local distribution network, e.g. communicating with another STB or one or more peripheral devices inside the home
    • H04N21/4363—Adapting the video or multiplex stream to a specific local network, e.g. a IEEE 1394 or Bluetooth® network
    • H04N21/43637—Adapting the video or multiplex stream to a specific local network, e.g. a IEEE 1394 or Bluetooth® network involving a wireless protocol, e.g. Bluetooth, RF or wireless LAN [IEEE 802.11]
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/76—Television signal recording
    • H04N5/765—Interface circuits between an apparatus for recording and another apparatus
    • H04N5/775—Interface circuits between an apparatus for recording and another apparatus between a recording apparatus and a television receiver

Abstract

An automatic audio and video output circuit has a plurality of audio (<B>12</B>) and video (<B>10</B>) inputs (e.g. provided from various equipment) which provide input signals to an electronic switch (<B>18</B>). The switch is controlled by a central processing unit (<B>16</B>) which itself receives and stores (e.g. in an internal memory) information representing the order in which signals are inputted to the circuit. Upon detecting that the last inputted signal is turned off, the CPU controls the switch so that the previously inputted signal is output. The signals outputted from the switch are amplified (<B>20</B>, <B>22</B>) and provided to a television (<B>34</B>) or a S terminal TV (<B>32</B>) for reproduction of sound and picture. The signals may be transmitted to a TV via a radio link (<B>26</B>, <B>30</B>).

Description

AUTO AUDIO/VIDEO OUTPUT CIRCUIT WITH MULTIPLE AUDIO/VIDEO INPUTS BACKGROUND OF THE INVENTION The present invention relates to an auto audio/video output circuit with multiple audio/video inputs, and more particularly to such an auto audio/video output circuit which receives inputted audio/video signals from different audio/video equipment, and selects the last inputted audio/video signal for output.
A regular audio/video output device, for example a TV, has only one set of audio/video input terminals. When connecting different audio/video equipment to a TV, a selector shall be used and connected between the TV and the audio/video equipment, so that the user can select one audio/video equipment for output to the TV.
Further, a variety of audio/video equipment including DVD, VDC, video tape recorder/player, V8, video cassette recorder, etc. have been developed, and have appeared on the market. Various adapters are known, and used for connection between different audio/video equipment. These adapters are commonly made from wave band switches or wave link switches. Because these switches are passive devices, they cannot automatically set the output signal channel. When in use, the user have to find the accurate output channel for signal output. Because these switches are mechanical
devices, they wear quickly with use. There are also known remote-controlled audio/video adapters for controlling the connection between audio/video equipment. These remotecontrolled audio/video adapters are convenient in use, however their manufacturing cost is high.
SUMMARY OF THE INVENTION The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide an auto audio/video output circuit with multiple audio/video inputs which receives audio/video input signals from different audio/video equipment, and automatically replaces the previously inputted audio/video signal with the last inputted audio/video signal for output, and automatically catches the previously inputted audio/video signal (if not turned off) when the last inputted audio/video signal is turned off. It is another object of the present invention to provide an auto audio/video output circuit with multiple audio/video inputs which is an electronic circuit without mechanical switch means.
BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a circuit block diagram of the present invention.
Figure 2 is a detailed circuit diagram of the present invention.
Figure 3 shows an output state of the present invention where only one audio/video equipment is turned on.
Figure 4 shows an output state of the present invention where multiple audio/video equipment are turned on.
Figure 5 is a circuit block diagram of an alternate form of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to Figures I and 2, an auto auto-video output circuit in accordance with the present invention is generally comprised of a video input interface 10, an audio input interface 12 including a left sound channel input interface 120 and a right sound channel input interface 122, an analog/digital converter 14, a CPU (central processing unit) 16, an analog electronic switch unit 18, a video output amplifier 20, and an audio output amplifier unit 22 including a left sound channel amplifier 220 and a right sound channel amplifier 222.
The video input interface 10 has a plurality of input terminals VinA; VinB; VinC; VinD; VinE for receiving video signals from a plurality of audio/video equipment, and a plurality of output terminals respectively connected to input terminals of the analog/digital converter 14 and input terminals of the analog electronic switch unit 18. Video signals from the audio/video
equipment are respectively transmitted to the analog/digital converter 14, and converted into corresponding digital signals. The analog/digital converter 14 is comprised of a plurality of analog to digital converting ICs (see U5 in Figure 2). The analog to digital converting ICs of the analog/digital converter 14 receive video output signals from the output terminals of the video input interface 10. When one analog to digital converting IC of the analog/digital converter 14 receives a video output signal from the corresponding output terminal of the video input interface 10, it provides a high potential output signal to a respective video input pin at the CPU 16 (see U6 in Figure 2). When several audio/video equipment are turned on, the video signals are transmitted in proper order to the respective video input pins of the CPU 6 through the video input interface 10 via the analog/digital converter 14, and then stored in internal memory means in the. CPU 6, and the video signal from the audio/video equipment which was last turned on is selected and processed for output (this will be described further).
The input terminals of the left sound channel input interface 120 and the right sound channel input interface 122 of the audio input interface 12 are respectively connected to the left sound channel output terminals and right sound channel output terminals of the audio/video equipment. The output terminals of the left sound
channel input interface 120 and the right sound channel input interface 122 of the audio input interface 12 are respectively connected to the respective input terminals of the analog electronic
switch unit 18. Input signals VinA-ALA-ARA ; Vins, ALB-ARB ; VinCALC ARC ; VinD ALD-ARD ; VinE ALE.. ARE from the video input interface 10 and the audio input interface 12 are respectively connected to respective input terminals of the analog electronic switch unit 18.
The output terminals of the analog electronic switch unit 18 are respectively connected to the input terminals of the video output amplifier 20, the left sound channel amplifier 220 and the right sound channel amplifier 222. The analog electronic switch unit 18 has a control terminal connected to one output pin of the CPU 16.
When the CPU 16 judges one input signal to be the last input signal, it immediately outputs a control signal to the control terminal of the analog electronic switch unit 18, causing the analog electronic switch unit 18 to select the desired video signal left/right sound channel signal for output to the video output amplifier 20 or the left/right sound channel amplifier 220 (222).
When the user turns on one audio/video equipment, the signal outputted from the audio/video equipment is detected by the CPU 16, causing the analog electronic switch unit 18 to open the
corresponding output terminal, permitting the video signal to be transmitted to the corresponding amplifier.
Referring to Figure 3 and Figure 2 again, when only one Av signal (VinA"ALA"ARA) is inputted to the analog/digital converter 14, the analog/digital converter 14 catches one segment of the video signal VinA from the inputted Av signal and converts it into a high potential voltage signal, then outputs the high potential voltage signal to the CPU 16, enabling the CPU 16 to memorize the video signal VinA as a first input signal. After the first input signal has been memorized in memory means in the CPU 16, the CPU 16 immediately outputs a high potential to the analog electronic switch unit 18 (the analog electronic switch unit 18 is comprised of switching ICs U1 ; U2; U3; U4), causing it to output the selected signal VinA"ALA"ARA to a regular TV 34 through the amplifiers 20; 220; 222.
Referring to Figure 4 and Figure 2 again, when different audio/video equipment are irregularly turned on at different times, the CPU 16 memorizes the sequences of the inputted video signals (see Figure 4) and let the last inputted audio/video signals (i. e., number 5) be transmitted the regular TV 34 through the amplifiers 20; 220; 222 (according to the present embodiment, these amplifiers are transistor amplifier circuits).
Referring to Figure I again a transmitter circuit 26 may be provided and connected to the output terminals of the video output amplifier 20, the left sound channel amplifier 220 and the right sound channel amplifier 222 for signal output by radio to a radio receiver TV 30. Further, a Y/C signal separator 24 may be installed to output amplified signals to a S terminal TV 32.
Figure 5 is a circuit block diagram of an alternate form of the present invention, in which a time delay circuit 28 (RC circuit) is connected between the analog/digital converter 14 and the CPU 16 to extend the existing time of the high potential signals by means of a charging discharging operation.
It is to be understood that the drawings are designed for purposes of illustration only, and are not intended as a definition of the limits and scope of the invention disclosed.

Claims (13)

  1. What the invention claimed is : 1. An auto audio/video output circuit comprising: a video input interface having a plurality of signal input terminals for receiving video signal from at least one audio/video equipment, and a plurality of signal output terminals : at least one audio input interface each having a plurality of signal input terminals for receiving audio signal from at least one audio/video equipment and a plurality of signal output terminals; at least one analog/digital converter respectively connected to the signal output terminals of said video input interface for converting video signal into corresponding digital signal; a CPU (central processing unit) having a plurality of signal input pins respectively connected to respective signal output terminals of said at least one analog/digital converter for receiving converted digital signals from said analog/digital converter, permitting received digital signals to be memorized in proper order in memory means in said CPU, and a control signal output pin; an analog electronic switch unit having a plurality of signal input terminals respectively connected to the signal output terminals of said video input interface and the signal output terminals of said at least one audio input interface, a plurality of signal output terminals, and a control terminal connected to the control signal
    output pin of said CPU to receive a control signal from said CPU for controlling the closing/opening of the signal output terminals of said electronic switch unit; a video output amplifier having a plurality of video signal input terminals respectively connected to the signal output terminals of said analog electronic switch unit to receive video signals from said analog electronic switch unit, and a video signal output terminal; and an audio output amplifier having a plurality of signal input terminals respectively connected to the signal output terminals of said analog electronic switch unit to receive audio signals from said analog electronic switch unit and a plurality of audio signal output terminals; wherein the video signal output terminal of said video output amplifier and the audio signal output terminals of said audio output amplifier are respectively connected to the video input terminal and audio input terminals of a TV for output.
  2. 2. An auto audio/video output circuit comprising: a video input interface having a plurality of signal input terminals for receiving video signal from at least one audio/video equipment, and a plurality of signal output terminals; at least one audio input interface each having a plurality of
    signal input terminals for receiving audio signal from at least one audio/video equipment and a plurality of signal output terminals; at least one analog/digital converter respectively connected to the signal output terminals of said video input interface for converting video signal into corresponding digital signal; a CPU (central processing unit) having a plurality of signal input pins respectively connected to respective signal output terminals of said at least one analog/digital converter for receiving converted digital signals from said analog/digital converter, permitting received digital signals to be memorized in proper order in memory means in said CPU, and a control signal output pin; an analog electronic switch unit having a plurality of signal input terminals respectively connected to the signal output terminals of said video input interface and the signal output terminals of said at least one audio input interface, a plurality of signal output terminals, and a control terminal connected to the control signal output pin of said CPU to receive a control signal from said CPU for controlling the closing/opening of the signal output terminals of said electronic switch unit; a video output amplifier having a plurality of video signal input terminals respectively connected to the signal output terminals of said analog electronic switch unit to receive video signals from
    said analog electronic switch unit, and a video signal output terminal ; and an audio output amplifier having a plurality of signal input terminals respectively connected to the signal output terminals of said analog electronic switch unit to receive audio signals from said analog electronic switch unit and a plurality of audio signal output terminals; and a radio transmitter connected to the signal output terminals of said analog electronic switch unit; wherein the video signal output terminal of said video output amplifier and the audio signal output terminals of said audio output amplifier are respectively connected to the video input terminal and audio input terminals of a TV, so that an audio/video signal set can be provided to the connected TV or a radio receiver TV for output after audio/video signals from audio/video equipment have been inputted into said video input interface and said at least one audio input interface.
  3. 3. An auto audio/video output circuit comprising: a video input interface having a plurality of signal input terminals for receiving video signal from at least one audio/video equipment, and a plurality of signal output terminals; at least one audio input interface each having a plurality of
    signal input terminals for receiving audio signal from at least one audio/video equipment and a plurality of signal output terminals; at least one analog/digital converter respectively connected to the signal output terminals of said video input interface for converting video signal into corresponding digital signal ; a CPU (central processing unit) having a plurality of signal input pins respectively connected to respective signal output terminals of said at least one analog/digital converter for receiving converted digital signals from said analog/digital converter, permitting received digital'signals to be memorized in proper order in memory means in said CPU, and a control signal output pin; an analog electronic switch unit having a plurality of signal input terminals respectively connected to the signal output terminals of said video input interface and the signal output terminals of said at least one audio input interface, a plurality of signal output terminals, and a control terminal connected to the control signal output pin of said CPU to receive a control signal from said CPU for controlling the closing/opening of the signal output terminals of said electronic switch unit; a video output amplifier having a plurality of video signal input terminals respectively connected to the signal output terminals of said analog electronic switch unit to receive video signals from
    said analog electronic switch unit, and a video signal output terminal ; and an audio output amplifier having a plurality of signal input terminals respectively connected to the signal output terminals of said analog electronic switch unit to receive audio signals from said analog electronic switch unit and a plurality of audio signal output terminals; a radio transmitter connected to the signal output terminals of said analog electronic switch unit; and a Y/C signal separator connected to the signal output terminals of said analog electronic switch unit; wherein the video signal output terminal of said video output amplifier and the audio signal output terminals of said audio output amplifier are respectively connected to the video input terminal and audio input terminals of a TV, so that an audio/video signal set can be provided to the connected TV, a radio receiver TV, or a S terminal TV for output after audio/video signals from audio/video equipment have been inputted into said video input interface and said at least one audio input interface.
  4. 4. The auto audio/video output circuit of claim 1 further comprising a time delay circuit connected between said at least one analog/digital converter and said CPU to extend the digital signals
    transmitted from said least one analog/digital converter to said CPU.
  5. 5. The auto audio/video output circuit of claim 2 further comprising a time delay circuit connected between said at least one analog/digital converter and said CPU to extend the digital signals transmitted from said least one analog/digital converter to said CPU.
  6. 6. The auto audio/video output circuit of claim 3 further comprising a time delay circuit connected between said at least one analog/digital converter and said CPU to extend the digital signals transmitted from said least one analog/digital converter to said CPU.
  7. 7. An auto audio/video output circuit substantially as herein described and illustrated with reference to accompanying drawings, of Figures 1,2, 3, 4 & 5.
  8. 8. An auto audio/video output circuit with multiple audio/video inputs which receives audio/video signals from different audio/video equipment, and automatically replaces the previously inputted audio/video signal with the last inputted audio/video signal for output, and automatically catches the previously inputted audio/video signal (if not turned off) when the last inputted audio/video signal is turned off.
  9. 9. An auto switching circuit comprising: a plurality of inputs; at least one output; a switching unit for routing a signal from one of said inputs to said output; input detection means for detecting a signal being switched on or off at each of said inputs; memory means for storing information regarding the sequence in which signals on said inputs are switched on or off; and control signal generating means for generating a control signal for controlling said switching unit, wherein said information stored in said memory means is used to generate said control signal.
  10. 10. An auto switching circuit as claimed in claim 9, wherein when a new signal is switched on at one of said inputs, said switching unit routes this new signal to the output; and when a signal being routed to said output is switched off, said control signal generating means consults said memory means and said switching unit routes the signal which was next most recently switched on to the output.
  11. 11. An auto switching circuit as claimed in claim 9 or 10, wherein said inputs are adapted to receive audio and/or video signals.
  12. 12. An auto switching circuit as claimed in claim 9,10 or 11, wherein each said input comprises means for simulaneously carrying a video, a right audio, and a left audio signal, said output comprises means for carrying a video, a right audio, and a left audio signal, and said switching unit is adapted to switch the video, right audio and left audio signals from any selected input to the output.
  13. 13. An auto switching circuit as claimed in any one of claims 9 to 12, wherein said control signal generating means comprises an input for an over-ride signal, and said control signal is generated according to both said information stored in said memory means, and said over-ride signal.
GB0108377A 2001-04-03 2001-04-03 Automatic audio-video output circuit Withdrawn GB2374226A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB0108377A GB2374226A (en) 2001-04-03 2001-04-03 Automatic audio-video output circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB0108377A GB2374226A (en) 2001-04-03 2001-04-03 Automatic audio-video output circuit

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GB0108377D0 GB0108377D0 (en) 2001-05-23
GB2374226A true GB2374226A (en) 2002-10-09

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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6118496A (en) * 1998-03-03 2000-09-12 Ho; Chin-Chi Auto audio/video output circuit with multiple audio/video inputs

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6118496A (en) * 1998-03-03 2000-09-12 Ho; Chin-Chi Auto audio/video output circuit with multiple audio/video inputs

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Publication number Publication date
GB0108377D0 (en) 2001-05-23

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