Television – Basic receiver with additional function – Multimode
Reexamination Certificate
2001-10-05
2003-07-08
Miller, John (Department: 2614)
Television
Basic receiver with additional function
Multimode
C348S725000, C348S726000, C348S731000, C348S729000, C348S385100, C348S388100
Reexamination Certificate
active
06590615
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a digital video receiving apparatus for receiving a digital video signal in relation to a digital TV, a digital CATV and a digital broadcasting device.
DESCRIPTION OF THE PRIOR ART
FIG. 14
shows a multimedia information processing apparatus disclosed in “a codec having broadcasting quality for satellite communication”, Hattori, Tanaka, Asano, Asai and Sakado, Mitsubishi Denki Technical Gazette, Vol. 67, No. 7, pp. 33-38 (1993).
A conventional digital video receiving apparatus is explained using FIG.
13
and FIG.
14
.
FIG. 13
shows an example of a signal frequency layout on a satellite transponder having a two-wave transmission mode. In
FIG. 13
, a high picture quality mode means a mode for transmitting two-waves on a transponder and a higher quality video and audio. SNG (Satellite News Gathering) multiplex mode means a mode for multiplexing two programs of SNG mode, which can transmit four waves in maximum via a transponder of a communication satellite “Super Bird”, and for transmitting two video programs via one wave. In
FIG. 13
, the two-waves are multiplexed and each wave multiplexes two programs.
When the two-waves shown in
FIG. 13
are demultiplexed and received simultaneously, four program digital video receiving apparatuses
400
(two apparatuses×two programs) (shown in
FIG. 14
) are necessary. In the high picture quality mode, one wave carries one program, but in the SNG multiplex mode two programs are carried in one wave as shown in FIG.
14
. The decoding operation of the SNG multiplex mode is explained below.
In
FIG. 14
, a down converter
402
selects any one of SNG multiplexed waves
511
or
512
in
FIG. 13
from a received IF (Intermediate Frequency) signal
401
. QPSK demodulator
403
digitally demodulates the selected wave. A Viterbi decoder
404
corrects errors and a 2CH demultiplexer
410
demultiplexes a wave signal into two programs. One of the program signals is corrected through a de-interleave portion
411
, a Reed-Solomon decoder
412
and a de-scramble portion
413
and outputted to a demulitplexer
430
.
The other program signal is demultiplexed by the 2CH demultiplexer
410
into a digital video output
422
, which is inputted into the 2CH demultiplexer
410
of the other program digital video receiving apparatus
400
as a digital video output
421
. The output signal from the 2CH demultiplexer
410
of the other program digital video receiving apparatus
400
is also corrected through the circuits
411
,
412
and
413
and outputted to the demultiplexer
430
in the same manner as described above.
Conventionally, one SNG multiplexed wave includes two programs. The respective SNG multiplexed wave is demultiplexed into one program by the 2CH demultiplexer
410
and outputted to the demultiplexer
430
. A video decoder
432
receives a VBI (vertical blanking line interval) signal
431
from the demultiplexer
430
and outputs a video signal
441
to a terminal. An audio decoder
433
decodes an audio coded signal received from the demultiplexer
430
to output an audio signal
422
. Similarly, an order-wire-interface
434
outputs a communication signal
443
and a data-interface
435
outputs a terminal data signal
444
.
Conventionally, only digitally coded programs can be received. Therefore, an analog video picture and a digital video picture cannot be received by the same receiving terminal apparatus.
A conventional digital video receiving terminal apparatus only can receive one digital video program, but it cannot display a multi-channel digital video picture.
Also, the conventional digital video receiving terminal apparatus cannot display respective different digital video pictures on a plurality of terminals (monitors).
A data demultiplexer of the conventional digital video receiving terminal apparatus can only demultiplex data accompanied with one program, but it cannot demultiplex data corresponding to a plurality of digital video programs.
For example, when the computing quantity for decoding HDTV (High Definition Television) of a high picture quality digital TV is six times as much as that for SDTV (Standard Definition Television) of a normal digital TV, a data decoder of the conventional digital video receiving terminal apparatus can decode one HDTV picture or one SDTV picture, but it cannot decode a plurality of SDTV pictures, simultaneously, or a plurality of SDTV pictures plus one HDTV picture, simultaneously.
SUMMARY OF THE INVENTION
It is an object of the present invention to be able to see different programs independently on a plurality of monitors using one digital video receiving apparatus.
It is another object of the present invention to be able to see one HDTV program as well as a plurality of SDTV programs at the same time on a monitor using one digital video receiving apparatus.
It is a further object of the present invention to be able to see digital TV programs sent by digital signal as well as analog TV programs sent by analog signal at the same time on a monitor using one digital video receiving apparatus.
According to one aspect of the invention, a digital video receiving apparatus receives digital broadcasting programs including a plurality of multiplexed media such as video, audio and data, and provides the programs to subscribers. The apparatus includes a tuner for receiving a multiplexed signal and converting it to a digital base band signal and a demodulator for decoding the digital base band signal provided from the tuner. The apparatus further includes a demultiplexer for selecting one or more programs from the multiplexed programs including a plurality of media such as a video signal, an audio signal and a data signal according to a program selection signal provided from outside, and for demultiplexing respective bit streams including a video signal, an audio signal or a data signal. The apparatus further includes a video decoder for decoding the video signal demultiplexed by the demultiplexer, an audio decoder for decoding the audio signal demultiplexed by the demultiplexer, and a data decoder for decoding the data signal demultiplexed by the demultiplexer.
According to another aspect of the invention, the video decoder in the digital video receiving apparatus includes a bit stream divider and a plurality of video decoding units, each of the video decoding units including a partial video decoder and a memory. The bit stream divider generates video streams including a video signal, an audio signal and a data signal for each channel, using a clock and a stream identification signal. Each video decoding unit decodes the respective video stream for each channel using the partial video decoder and the memory, and outputs the decoded signal as a video output signal.
According to a further aspect of the invention, the digital video receiving apparatus further includes a channel demultiplexer for generating a video stream, a clock signal and a stream identification signal for each channel, using a bit stream including a video signal, an audio signal and a data signal, a clock signal and a stream identification signal each of which is outputted from the demultiplexer. The video decoder, the audio decoder and the data decoder process the respective signals for each channel, decode and output the video signal, the audio signal and the data signal for each program.
According to a still further aspect of the invention, the video decoder in the digital video receiving apparatus includes a plurality of video decoding units, each of the video decoding units including a partial video decoder and a memory. Each video decoding unit decodes the bit stream including a video signal, an audio signal and a data signal outputted from the channel demultiplexer, using a clock signal and a stream identification signal, and outputs a decoded signal as a video output signal.
According to a further aspect of the invention, a digital video receiving apparatus receives digital broadcasting programs including a plurality of multiplexed media such as a video, audio and d
Murakami Tokumichi
Ohira Hideo
Miller John
Natnael Paulos
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