Multiplex communications – Communication techniques for information carried in plural... – Adaptive
Reexamination Certificate
1997-09-02
2001-08-28
Hsu, Alpus H. (Department: 2662)
Multiplex communications
Communication techniques for information carried in plural...
Adaptive
C370S469000, C345S504000, C348S014160, C709S208000
Reexamination Certificate
active
06282205
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates, generally, to an apparatus for interconnecting audio, video, and data components. More particularly, it relates to an apparatus that eliminates the noise and errors that occur during analog data transmission between such components.
2. Description of the Prior Art
A conventional audio component such as a speaker is connected to a source of audio signals by wires that carry analog signals. The speaker must therefore be positioned in relatively close proximity to the source of the audio signals if signal attenuation is to be minimized. However, even if the speaker is positioned in close proximity to the source of audio signals, the analog signal transmission will be imperfect. Moreover, extraneous noise will be induced because it is not possible to perfectly shield the wires that extend from the signal source to the speaker. Furthermore, there are many audio, video, or data components where more than one wire is required to make the interconnection. Where there are a relatively large number of audio and video components to be interconnected, such as in a home entertainment center having a television set (which may be of the analog or digital type and which may include a video monitor and the like), a VCR, a CD player, a DVD player, a casette tape player, a radio tuner, a television tuner, a graphics equalizer, and the like, the number of wires is quite high and the connections are rather complicated and messy.
Another drawback of the present system for interconnecting components is that the number of components that may be interconnected is limited. Once the “audio in,” “audio out,” “video in,” and “video out” ports of a component such as a VCR have been occupied, no further connections can be made.
What is needed, then, is a means for reducing or eliminating signal transmission errors of the type that occur in analog environments, for reducing or eliminating the amount of noise that exists in a conventional set up of multiple components that includes analog components, a means for reducing the number of wires in such a set up so that intallation complexity is reduced, a means that would enable various audio, video, or data components to be widely spaced apart from their respective signal sources and from each other, a means for providing positive communication between the various components of such a system, and a means for increasing the number of components that may be interconnected.
However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in this art how these desireable ends could be attained.
SUMARY OF THE INVENTION
The longstanding but heretofore unfulfilled need for an apparatus that overcomes the limitations of the prior art is now met by a new, useful, and nonobvious invention. The present invention includes an apparatus interconnecting a network of components in a master/slave relationship so that each component is controlled by the master. The apparatus is called a
D
igital
A
udio-
Vi
deo N
e
twork
S
ystem (DAVieS) and includes a central control unit for controlling a plurality of components. The central control unit has digital internal circuitry.
At least one component of the plurality of components has analog internal circuitry. A single physical transmission path for interconnecting the central control unit to each component of the plurality of components is provided. The transmission paths is in the form of a predetermined signal transmission media, and at least one decoder D/A (digital-to-analog) unit, hereinafter referred to as a DDA means, is provided for decoding and converting digital signals from the central control unit to decoded analog signals at the input of said at least one component having analog internal circuitry. Said at least one DDA means is positioned at the input of said at least one component and there may be as many DDA means as there are components having internal analog circuitry.
At least one A/D (analog-to-digital) encoder unit, hereinafter referred to as an ADE means, is provided for encoding and converting analog signals from said at least one component having analog internal circuitry to encoded digital signals, and said at least one ADE means is positioned at the output of said at least one component having analog internal circuitry. There may be as many ADE means as there are components having analog internal circuitry.
The components of any DAVieS may include input devices, output devices, and input/output devices. An ADE means will be positioned between the DAVieS and all input devices, such as an FM radio with an independently controlled tuner, for example. A DDA means will be positioned between the DAVieS and all output devices, such as a speaker, for example. Both ADE and DDA means will be positioned between the DAVieS and all input/output devices, such as a TV tuner, for example.
The DDA meanss and the ADE means are under the control of the central control unit so that no signal travels from a component to the central control unit unless the central control unit commands a component to send a signal and so that no signal travels between components in the absence of a command from the central control unit. The central control unit is adapted to transmit digital commands to the components in accordance with a predetermined communication protocol.
Accordingly, all transmission and command signals in the network are digital. Thus, noise arising from analog signal transmission is eliminated, external induced noise is eliminated or substantially attenuated, the components may be remotely positioned from the central control unit and from each other without introducing noise, the wiring of the audio and video system is simplified, and the number of components that may be connected to the network is limitless for all practical purposes.
It is a primary object of this invention to overcome many of the limitations associated with analog transmission of signals in audio and video systems.
A more specific object is to provide an apparatus for interconnecting audio and video components that reduces signal transmission errors.
Another specific object is to provide an apparatus for reducing external induced noise in such a system.
Another object is to provide an interconnection system that would reduce the number of wires employed to set up a video and audio component system.
Still another object is to facilitate remote placement of components with respect to their respective sources of signals and with respect to each other.
It is also an object to provide a means for components to communicate with each other.
These and other important objects, features, and advantages of the invention will become apparent as this description proceeds.
The invention accordingly comprises the features of construction, combination of elements and arrangement of parts that will be exemplified in the construction hereinafter set forth, and the scope of the invention will be indicated in the claims.
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Hsu Alpus H.
Smith Ronald E.
Smith & Hopen , P.A.
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