U.S. patent application number 10/265855 was filed with the patent office on 2003-02-20 for method and apparatus for receiving digital broadcasts.
This patent application is currently assigned to Sony Corporation. Invention is credited to Inoue, Hajime, Nakano, Takehiko, Sato, Sadaharu, Yamamoto, Noriyuki.
Application Number | 20030037343 10/265855 |
Document ID | / |
Family ID | 12107873 |
Filed Date | 2003-02-20 |
United States Patent
Application |
20030037343 |
Kind Code |
A1 |
Inoue, Hajime ; et
al. |
February 20, 2003 |
Method and apparatus for receiving digital broadcasts
Abstract
In a digital broadcast receiving apparatus, digital broadcast
signals provided by a digital broadcast method are supplied to
various types of external units and are effectively utilized. In
the above apparatus, a descrambler descrambles a transport stream
output from a front end unit and supplies it to a digital interface
and a demultiplexer. The demultiplexer extracts from the transport
stream a compressed video signal and a compressed audio signal of a
program specified by a user, and supplies the extracted signals to
an MPEG decoder. The MPEG decoder decompresses the supplied video
signal and the audio signal and supplies them to the digital
interface, an NTSC encoder, and an audio signal D/A converter. The
digital interface supplies either of the transport stream or the
decompressed data to a digital external unit under the control of
the controller.
Inventors: |
Inoue, Hajime; (Chiba,
JP) ; Yamamoto, Noriyuki; (Tokyo, JP) ; Sato,
Sadaharu; (Tokyo, JP) ; Nakano, Takehiko;
(Kanagawa, JP) |
Correspondence
Address: |
LERNER, DAVID, LITTENBERG,
KRUMHOLZ & MENTLIK
600 SOUTH AVENUE WEST
WESTFIELD
NJ
07090
US
|
Assignee: |
Sony Corporation
Tokyo
JP
|
Family ID: |
12107873 |
Appl. No.: |
10/265855 |
Filed: |
October 7, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10265855 |
Oct 7, 2002 |
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09244282 |
Feb 3, 1999 |
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6467093 |
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Current U.S.
Class: |
725/151 ;
348/E5.002; 348/E5.005; 348/E5.007; 725/95 |
Current CPC
Class: |
H04N 21/42646 20130101;
H04H 60/80 20130101; H04N 21/434 20130101; H04N 21/4147 20130101;
H04N 21/8106 20130101; H04H 60/27 20130101; H04N 21/440218
20130101; H04N 21/4334 20130101; H04N 7/162 20130101; H04H 40/90
20130101; H04N 21/4117 20130101; H04N 21/436 20130101; H04N 21/426
20130101 |
Class at
Publication: |
725/151 ;
725/95 |
International
Class: |
H04N 007/16 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 4, 1998 |
JP |
P10-023340 |
Claims
What is claimed is:
1. A digital broadcast receiving apparatus comprising: broadcast
program extraction means for extracting compressed data including a
broadcast program selected and specified by a user; decompression
means for decompressing the compressed data extracted by said
broadcast program extraction means and for outputting decompressed
data; digital interface means for receiving-the compressed data
extracted by said broadcast program extraction means and the
decompressed data from said decompression means, and for outputting
each of the compressed data and the decompressed data to a digital
external unit; and control means for controlling, based on an
instruction from the user, the selection of an output of the
compressed data extracted by said broadcast program extraction
means or an output of the decompressed data from said decompression
means to the digital external unit from said digital interface
means.
2. The digital broadcast receiving apparatus according to claim 1,
wherein said broadcast program extraction means comprises a tuner
for selecting a carrier component including the broadcast program
selected and specified by the user, a front end unit for
demodulating the carrier component selected by said tuner and for
outputting a transport stream, and selected-program extraction
means for extracting compressed data of the broadcast program
selected and specified by the user from the transport stream output
from said front end unit, and said broadcast program extraction
means outputs the transport stream from said front end unit to said
digital interface means and also outputs the compressed data of the
broadcast program from said selected-program extraction means to
said decompression means; wherein said digital interface means
receives the transport stream from said front end unit and
decompressed data from said decompression means and outputs each of
the transport stream and the decompressed data to the digital
external unit; and wherein said control means controls, based on an
instruction from the user, the selection of an output of the
transport stream or the decompressed data to the digital external
unit from said digital interface means.
3. The digital broadcast receiving apparatus according to claim 1,
wherein the compressed data comprises data which is compressed by
an MPEG method.
4. A digital broadcast receiving apparatus for receiving a mixture
of broadcast program signals provided as non-compressed data and
broadcast program signals provided as compressed data, said
apparatus comprising: a tuner for selecting a carrier component
including a signal of a broadcast program selected and specified by
a user; a front end unit for demodulating the carrier component
selected by said tuner and for outputting a transport stream;
selected-program extraction means for extracting the non-compressed
data or the compressed data of the broadcast program selected and
specified by the user from the transport stream supplied from said
front end unit; digital interface means for receiving the transport
stream from said front end unit and the non-compressed data
extracted by said selected-program extraction means and for
outputting each of the transport stream and the non-compressed data
to a digital external unit; and control means for controlling,
based on an instruction from the user, the selection of an output
of the transport stream or the non-compressed data to the digital
external unit from said digital interface means.
5. The digital broadcast receiving apparatus according to claim 4,
further comprising decompression means for decompressing, in a case
where the signal of the broadcast program extracted by said
selected-program extraction means is compressed data, the
compressed data, and for outputting decompressed data; wherein said
digital interface means receives the transport stream from said
front end unit, the non-compressed data from said selected-program
extraction means, and the decompressed data from said decompression
means, and outputs each of the transport stream, the non-compressed
data, and the decompressed data to the digital external unit; and
wherein said control means controls, based on an instruction from
the user, the selection of an output of the transport stream, the
non-compressed data, or the decompressed data from said digital
interface means.
6. The digital broadcast receiving apparatus according to claim 4,
wherein the compressed data comprises data which is compressed by
an MPEG method.
7. The digital broadcast receiving apparatus according to claim 4,
wherein the non-compressed data comprises digital data compressed
by a method other than an MPEG method.
8. A method of receiving a digital broadcast comprising the steps
of: (a) extracting a compressed data including a broadcast program
selected and specified by a user; (b) decompressing the compressed
data extracted in said extracting step (a) and outputting
decompressed data; (c) outputting each of the compressed data
extracted in said extracting step (a) and the decompressed data
output from said decompressing step (b) to a digital external unit;
and (d) controlling, based on an instruction from the user, the
selection of an output of the compressed data extracted in said
extracting step (a) and the decompressed data output from said
decompressing step (b) to the digital external unit from
said-outputting step (c).
9. The digital broadcast receiving method according to claim 8,
wherein said extracting step (a) comprises the steps of: (e)
selecting a carrier component including a signal of the broadcast
program selected and specified by the user; (f) demodulating the
carrier component selected in said selecting step (e) and
outputting a transport stream; (g) extracting the compressed data
of the broadcast program selected and specified by the user from
the transport stream output from said demodulating step (f), and
said extracting step (a) outputs the transport stream from said
demodulating step (f) to said outputting step (c), and also outputs
the compressed data of the broadcast program from said
selected-program extracting step (g); wherein said outputting step
(c) outputs each of the transport stream output from said
demodulating step (f) and the decompressed data from said
decompressing step (b) to a digital external unit; and wherein said
controlling step (d) controls, based on an instruction from the
user, the selection of an output of the transport stream or the
decompressed data from said outputting step (c) to the digital
external unit.
10. A method of receiving a digital broadcast, which is a mixture
of broadcast program signals provided as non-compressed data and
broadcast program signals provided as compressed data, comprising
the steps of: (h) selecting a carrier component including a signal
of a broadcast program selected and specified by a user; (i)
demodulating the carrier component selected in said carrier
component selecting step (h) and outputting a transport stream; (j)
extracting the non-compressed data or the compressed data of the
broadcast program selected and specified by the user from the
transport stream output from said demodulating step (i); (k)
receiving the transport stream from said demodulating step (i) and
the non-compressed data extracted in said extracting step (j), and
outputting each of the transport stream and the non-compressed data
to a digital external unit; and (l) controlling, based on an
instruction from the user, the selection of an output of the
transport stream or the non-compressed data from said receiving
step (k) to the digital external unit.
11. The digital broadcast program receiving method according to
claim 10, further comprising the step of: (m) decompressing a
compressed data, in a case where the signal of the broadcast
program extracted in said extracting step (j) is compressed data,
and outputting decompressed data; wherein said receiving step (k)
outputs each of the transport stream from said demodulating step
(i), the non-compressed data from said extracting step (j), and the
decompressed data from said decompressing step (m) to the digital
external unit; and wherein said controlling step (l) controls,
based on an instruction from the user, the selection of an output
of the transport stream, the non-compressed data, or the
decompressed data from said receiving step (k).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method and an apparatus
for receiving digital broadcast signals, for example, digital
satellite broadcast signals.
[0003] 2. Description of the Related Art
[0004] As television broadcast systems using geostationary
satellites, digital broadcast systems, as well as analog broadcast
systems, are coming into use. In the digital broadcast system,
signals representing a plurality of television programs compressed
according to, for example, the Moving Picture Experts Group (MPEG)
method, can be multiplexed onto a single carrier and then be
provided.
[0005] In a digital broadcast receiving apparatus, a user selects a
carrier including the multiplexed television broadcast program that
the user would like to audio-visually observe. The selected carrier
is then demodulated, thereby obtaining a transport stream in which
compressed data representing a plurality of television broadcast
programs are multiplexed.
[0006] The compressed data of the target television broadcast
program is then extracted from the transport stream. The extracted
compressed data is decompressed, and an analog output video signal
and an analog output audio signal are formed from the decompressed
digital data. Images and sound of the target television broadcast
program are reproduced from the analog output video signal and the
analog output audio signal, respectively.
[0007] The above type of digital broadcast receiving apparatus is
provided with a digital interface. Through this interface, a
transport stream in which compressed data representing a plurality
of broadcast programs are multiplexed can be supplied to and
recorded on, for example, a digital video tape recorder
(hereinafter referred to as the "DVTR"). Also, the recorded
transport stream can be supplied from the DVTR to the digital
broadcast receiving apparatus, and a television broadcast program
contained in the supplied transport stream can be audio-visually
observed by using the digital broadcast receiving apparatus.
[0008] As discussed above, transport streams are supplied to and
received from the digital interface of the digital broadcast
receiving apparatus. Accordingly, it is impossible to record and
reproduce broadcast program signals output through the digital
interface by using only an apparatus that is not provided with a
compression/decompression function compatible with a compression
method used in digital broadcasting.
[0009] For example, it is now assumed that a broadcast program
signal provided by digital broadcasting has been recorded on a
video tape with a DVTR connected to a digital broadcast receiving
apparatus installed in a living room. Such a signal cannot be
reproduced by a DVTR installed in another room that is neither
connected to a digital broadcast receiving apparatus nor provided
with a compression/decompression function compatible with the
digital broadcast data compression method.
[0010] As noted above, the digital interface of the digital
broadcast receiving apparatus supplies and receives transport
streams. Thus, signals compressed by the MPEG method that are
normally used in broadcasts cannot be recorded on a recording
medium through this digital interface. For example, by using a
recording/reproducing apparatus that uses as a recording medium a
small magnetooptical disc, which is referred to as an MD, having a
compression format different from the MPEG method (this apparatus
will hereinafter be referred to as a "MD unit"), it is not possible
to record on the MD only digital audio signals of a target music
program or an education program concerning, for example, English
conversation.
[0011] As described above, in most cases, the transport streams
transmitted and received through the digital interface of a digital
broadcast receiving apparatus cannot be utilized without the
digital broadcast receiving apparatus. Accordingly, it is not
possible to record or reproduce only a target broadcast program on
or from a recording medium by using various digital external units,
such as a DVTR and an MD unit.
SUMMARY OF THE INVENTION
[0012] The present invention provides a method and an apparatus for
receiving digital broadcasts, in which broadcast program signals
provided by a digital broadcast system can be supplied to various
types of digital external units and be more effectively
utilized.
[0013] According to one aspect of the present invention, there is
provided a digital broadcast receiving apparatus comprising
broadcast program extraction means for extracting compressed data
including a broadcast program selected and specified by a user.
Decompression means decompresses the compressed data extracted by
the broadcast program extraction means and outputs decompressed
data. Digital interface means receives the compressed data
extracted by the broadcast program extraction means and the
decompressed data from the decompression means, and outputs each of
the compressed data and the decompressed data to a digital external
unit. Control means controls, based on an instruction from the
user, the selection of an output of the compressed data extracted
by the broadcast program extraction means or an output of the
decompressed data from the decompression means to the digital
external unit from the digital interface means.
[0014] This makes it possible to receive digital broadcasts in
which data is compressed and to directly supply the compressed data
of a target broadcast program to the digital external unit, or to
supply the decompressed data of a target broadcast program to the
digital external unit. Accordingly, it is possible to supply the
decompressed data even to a digital external unit which is not
provided with a decompression function compatible with the data
compression method of digital broadcasting and to utilize the
decompressed data by being recorded on a recording medium.
[0015] In the aforementioned digital broadcast receiving apparatus,
the broadcast program extraction means may comprise a tuner for
selecting a carrier component including the broadcast program
selected and specified by the user, a front end unit for
demodulating the carrier component selected by the tuner and for
outputting a transport stream, and selected-program extraction
means for extracting compressed data of the broadcast program
selected and specified by the user from the transport stream output
from the front end unit. The broadcast program extraction means may
output the transport stream from the front end unit to the digital
interface means and also outputs the compressed data of the
broadcast program from the selected-program extraction means to the
decompression means. The digital interface means may receive the
transport stream from the front end unit and decompressed data from
the decompression means and may output each of the transport stream
and the decompressed data to the digital external unit. The control
means may control, based on an instruction from the user, the
selection of an output of the transport stream or the decompressed
data to the digital external unit from the digital interface
means.
[0016] The extracted broadcast program signal may be digital data
which is compressed by, for example, the MPEG method. The digital
data is then supplied to the decompression means and is
decompressed, thereby reproducing the original digital data
(decompressed data).
[0017] This makes it possible to supply to the digital external
unit not only the transport stream in which a plurality of
broadcast program signals are multiplexed, but also to supply to
the digital external unit the decompressed data of a single
broadcast program and to record it on a recording medium used in
the digital external unit.
[0018] If the decompressed data of a single broadcast program is
recorded on a recording medium with the digital external unit, an
output audio signal can be formed with the digital external unit to
audio-visually observe the target broadcast program without needing
to input again the decompressed data into the digital broadcast
receiving apparatus provided with the decompression means.
[0019] According to another aspect of the present invention, there
is provided a digital broadcast receiving apparatus for receiving a
mixture of broadcast program signals provided as non-compressed
data and broadcast program signals provided as compressed data. The
digital broadcast receiving apparatus comprises a tuner for
selecting a carrier component including a signal of a-broadcast
program selected and specified by a user. A front end unit
demodulates the carrier component selected by the tuner and outputs
a transport stream. Selected-program extraction means extracts the
non-compressed data or the compressed data of the broadcast program
selected and specified by the user from the transport stream
supplied from the front end unit. Digital interface means receives
the transport stream from the front end unit and the non-compressed
data extracted by the selected-program extraction means, and
outputs each of the transport stream and the non-compressed data to
a digital external unit. Control means controls, based on an
instruction from the user, the selection of an output of the
transport stream or the non-compressed data to the digital external
unit from the digital interface means.
[0020] With this arrangement, a multi-program transport stream and
non-compressed data of a single broadcast program can be supplied
to the digital external unit according to an instruction from the
user. That is, the non-compressed data can be utilized by being
recorded on a recording medium used in the digital external unit.
Unlike the transport stream, the non-compressed data is not
required to be decompressed, and it is unnecessary to input the
non-compressed data into the digital broadcast receiving apparatus
again when being reproduced. It is thus possible to supply the
non-compressed data provided by digital broadcasting to the digital
external unit and to effectively utilize it by being recorded on a
recording medium.
[0021] The aforementioned digital broadcast receiving apparatus may
further comprise decompression means for decompressing, if the
signal of the broadcast program extracted by the selected-program
extraction means is compressed data, the compressed data, and for
outputting decompressed data. The digital interface means may
receive the transport stream from the front end unit, the
non-compressed data from the selected-program extraction means, and
the decompressed data from the decompression means, and may output
each of the transport stream, the non-compressed data, and the
decompressed data to the digital external unit. The control means
may control, based on an instruction from the user, the selection
of an output of the transport stream, the non-compressed data, or
the decompressed data from the digital interface means.
[0022] With this arrangement, the multi-program transport stream,
the non-compressed data, or the decompressed data can be supplied
to the digital external unit according to an instruction from the
user. In this case, the digital data to be supplied to the digital
external unit can be exchanged in accordance with the type of
digital external unit or the method for the use of data. This makes
it possible to supply the non-compressed data and the decompressed
data provided by digital broadcasting to the digital external unit
and to effectively utilize them by being recorded on a recording
medium. As a result, information provided by digital broadcasting
can be employed more effectively.
[0023] In the aforementioned digital broadcast receiving apparatus,
the compressed data may comprise data which is compressed by the
MPEG method. The non-compressed data may comprise digital data
compressed by a method other than the MPEG method.
[0024] According to still another aspect of the present invention,
there is provided a digital broadcast receiving method comprising:
a broadcast program extraction step of extracting compressed data
including a broadcast program selected and specified by a user; a
decompression step of decompressing the compressed data extracted
in the broadcast program extraction step and outputting
decompressed data; a digital interface step of outputting each of
the compressed data extracted in the broadcast program extraction
step and the decompressed data output from the decompression step
to a digital external unit; and a control step of controlling,
based on an instruction from the user, the selection of an output
of the compressed data extracted in the broadcast program
extraction step and the decompressed data output from the
decompression step to the digital external unit from the digital
interface step.
[0025] In the aforementioned digital broadcast receiving method,
the broadcast program extraction step may comprise a carrier
component selection step of selecting a carrier component including
a signal of the broadcast program selected and specified by the
user, a front end step of demodulating the carrier component
selected in the carrier component selection step and outputting a
transport stream, and a selected-program extraction step of
extracting compressed data of the broadcast program selected and
specified by the user from the transport stream output from the
front end step. The broadcast program extraction step may output
the transport stream to the digital interface step from the front
end step, and may also output the compressed data of the broadcast
program to the decompression step from the selected-program
extraction step. The digital interface step may output each of the
transport stream output from the front end step and the
decompressed data from the decompression step to the digital
external unit. The control step may control, based on an
instruction from the user, the selection of an output of the
transport stream or the decompressed data to the digital external
unit from the digital interface step.
[0026] According to a further aspect of the present invention,
there is provided a digital broadcast receiving method for
receiving a mixture of broadcast program signals provided as
non-compressed data and broadcast program signals provided as
compressed data. The digital broadcast receiving method comprises:
a carrier component selection step of selecting a carrier component
including a signal of a broadcast program selected and specified by
a user; a front end step of demodulating the carrier component
selected in the carrier component selection step and outputting a
transport stream; a selected-program extraction step of extracting
the non-compressed data or the compressed data of the broadcast
program selected and specified by the user from the transport
stream output from the front end step; a digital interface step of
receiving the transport stream from the front end step and the
non-compressed data extracted in the selected-program extraction
step and outputting each of the transport stream and the
non-compressed data to a digital external unit; and a control step
of controlling, based on an instruction from the user, the
selection of an output of the transport stream or the
non-compressed data to the digital external unit from the digital
interface step.
[0027] The aforementioned digital broadcast receiving method may
further comprise a decompression step of decompressing, if the
signal of the broadcast program extracted in the broadcast program
extraction step is compressed data, the compressed data, and
outputting decompressed data. The digital interface step may output
each of-the transport stream from the front end step, the
non-compressed data from the selected-program extraction step, and
the decompressed data from the decompression step to the digital
external unit. The control step may control, based on an
instruction from the user, the selection of an output of the
transport stream, the non-compressed data, or the decompressed data
from the digital interface step.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a block diagram illustrating a digital broadcast
receiving apparatus according to a first embodiment of the present
invention:
[0029] FIG. 2 illustrates a digital broadcast transport stream;
[0030] FIG. 3 is a block diagram illustrating a demultiplexer shown
in FIG. 1;
[0031] FIG. 4 is a block diagram illustrating the essential
elements of the digital broadcast receiving apparatus shown in FIG.
1 to which an audio-visual hard disk drive (AVHDD) unit is
connected;
[0032] FIG. 5 is a block diagram illustrating the essential
elements of the digital broadcast receiving apparatus shown in FIG.
1 to which a mini disc (MD) unit is connected;
[0033] FIG. 6 is a flow chart illustrating the operation performed
by the digital broadcast receiving apparatus shown in FIG. 1 when
digital data is output via a digital interface;
[0034] FIG. 7 is a block diagram illustrating a digital broadcast
receiving apparatus according to a second embodiment of the present
invention; and
[0035] FIG. 8 is a flow chart illustrating the operation performed
by the digital broadcast receiving apparatus shown in FIG. 7 when
digital data is output via a digital interface.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] A description is given hereinbelow, with reference to the
drawings, of embodiments of a method and an apparatus for receiving
digital broadcasts in accordance with the present invention. As
discussed above, there is a certain digital broadcast method in
which a plurality of broadcast programs are multiplexed on a single
carrier. In receiving apparatuses constructed in accordance with
the embodiments described below, signals containing a plurality of
multiplexed broadcast programs on a single carrier can be received
and demodulated to extract a signal of a target broadcast
program.
[0037] First Embodiment
[0038] FIG. 1 is a block diagram illustrating a digital broadcast
receiving apparatus 3 (hereinafter simply referred to as the
"receiving apparatus") according to a first embodiment of the
present invention. In FIG. 1, satellite broadcast waves in a 12 GHz
band received by a receiving antenna 1 are frequency-converted into
an intermediate frequency signal in a 1 GHz band by a low-noise
converter 2, and are then input into the receiving apparatus 3 of
the first embodiment via an input terminal 3in.
[0039] The receiving apparatus 3 of this embodiment is basically
formed of a received-signal processor 10, a digital interface 20
through which digital data is supplied to and received from digital
external units, and a controller 30. The received-signal processor
10, which includes a tuner 11, a front end unit 12, a transport
unit 13, and a decoding unit 14, outputs a broadcast program
selected by the user by executing processing, such as demodulating
a received and selected carrier.
[0040] The controller 30 serves as a microcomputer having a central
processing unit (CPU) 32, a dynamic random access memory (DRAM) 33,
a program read only memory (program ROM) 34, and a Japanese
Character (Kanji) ROM 35, all of which are connected via a bus 31,
and controls the individual elements of the receiving apparatus 3.
The DRAM 33 is used as a work area for the processing executed by
the controller 30. The program ROM 34 stores processing programs
executed by the controller 30 and data used for various processing.
The Kanji ROM 35 stores font data, such as Kanji font data, used
for characters and signs for display.
[0041] Connected to the controller 30 are a modem 41, an integrated
circuit (IC) card interface 42 (indicated as IC card I/F in FIG.
1), an interface 43 with a remote commander (indicated as a remote
controller I/F in FIG. 1), an interface 44 with a florescent
display tube provided for the main unit (indicated as a main-unit
display I/F in FIG. 1), and information can be transmitted and
received between the controller 30 and the above elements.
[0042] In this embodiment, the tuner 11 is formed as a
synthesizer-type tuner, and phase locked loop (PLL) data, which
serves as a channel-selecting control signal, i.e., data
representing the scaling ratio of a variable scaling circuit of a
PLL loop, is supplied to the tuner 11. The controller 30 is
provided with a memory for storing PLL data corresponding to each
channel, though this is not shown.
[0043] Upon receiving the PLL data, which serves as a
channel-selecting control signal, from the controller 30, the tuner
11 selects one of a plurality of carriers contained in the
intermediate frequency signal input via the input terminal 3in. The
carrier to be selected is determined by a remote command signal in
response to a channel selection command input from a remote
commander (not shown) according to the user's input operation.
[0044] That is, the user inputs a channel selection command by
operating the remote commander, and a remote command signal in
response to the channel selection command is output from the remote
commander. The remote command signal is input into the controller
30 of the receiving apparatus 3 through the remote commander I/F 43
connected to the controller 30, and the PLL data corresponding to
the remote command signal is supplied to the tuner 11 from the
controller 30. Alternatively, an operation button key provided for
the receiving apparatus 3 may be used to input a channel selection
command, though this is not shown.
[0045] The output of the tuner 11 is supplied to the front end unit
12. The front end unit 12 includes an analog-to-digital (A/D)
converter, a demodulator, a channel equalizer, an error correction
decoder, etc. The front end unit 12 converts the signal from the
tuner 11 into a digital signal, and performs digital demodulation
on the signal.
[0046] The front end unit 12 performs, so-called "ghost canceling",
on the digital-demodulated signal, based on the control information
from the controller 30, and also corrects bit errors generated on a
transmission channel, thereby obtaining a transport stream output.
In satellite digital television broadcasting, intensive
error-correction-code processing is applied to signals in order to
preserve the high and stabilized receiving quality even when
signals are received at a low carrier-to-noise (C/N) ratio due to
rain or other reason. For example, a modulation method using the
Viterbi code, the Reed Solomon code, and the Trellis code is
employed.
[0047] The front end unit 12 transmits to the transport unit 13 the
transport stream output obtained by demodulating and
error-correcting the signal. In the transport stream output, the
signal is, in most cases, scrambled for limited reception, such as
for pay broadcasting.
[0048] The transport unit 13 has, as shown in FIG. 1, a descrambler
131, a demultiplexer 132, and a DRAM 133 used as a work area for
performing demultiplex processing. The transport stream output from
the front end unit 12 is supplied to the descrambler 131 of the
transport unit 13. The transport stream signal is descrambled by
the descrambler 131.
[0049] In order to descramble the transport stream signal in the
descrambler 131, an IC card, which is provided by making a contract
with a digital broadcast company, is loaded into the IC card
interface 42 formed of an IC card reader. The user information,
such as contract conditions, is recorded on the IC card. The user
information can be overwritten by means such as performing
communications with the account center of the broadcast company via
the modem 41.
[0050] As described later, a descramble key, which is one of the
data required for limited reception and which is provided while
being multiplexed in the transport stream and extracted by the
demultiplexer 132, is supplied to the controller 30. Then, the
controller 30 determines, based on the contract information stored
in the IC card, whether the transport stream signal is permitted to
be descrambled in the receiving apparatus 3. If it is found that
the transport stream signal is permitted to be descrambled in the
receiving apparatus 3, the descramble key is supplied to the
descrambler 131 from the demultiplexer 132 so as to descramble the
transport stream signal.
[0051] The descrambled transport stream, which consists of a
plurality of multiplexed programs, is supplied to the demultiplexer
132. The transport stream is also supplied to the digital interface
20 in order to provide it to digital external units, which will be
discussed later.
[0052] FIG. 2 illustrates the configuration of a transport stream
consisting of a plurality of multiplexed programs. The transport
stream is, as illustrated in FIG. 2, a bit stream defined by the
MPEG system, and is a group consisting of 188-byte fixed-length
packets (transport packets).
[0053] Each transport packet is formed of a header, an adaptation
field for inputting additional information into a specific
individual packet, and a payload representing the content of each
packet. Stored in the payload are an MPEG-compressed video signal
(MPEG V), an MPEG-compressed audio signal (MPEG A), and program
data selected by the user, such as various types of data (indicated
by Web in FIG. 2), for example, homepages produced by Hyper Text
Markup Language (HTML) and game programs.
[0054] Further, transport packets storing channel selection data,
data representing, for example, a descramble key required for
limited reception, service information data for implementing an
Electronic Program Guide (EPG) are also multiplexed with transport
packets storing the program data. That is, in a transport stream,
packets storing data of a plurality of programs are multiplexed
with packets indicating program selection data and limited
reception data, and service information data.
[0055] The header of each transport packet is formed of four bytes,
and the leading byte is a synchronizing byte. The header stores not
only the synchronizing byte, but also a packet ID (PID)
representing packet identification information, and control
information concerning the presence or the absence of scrambling,
and the presence or the absence of the subsequent adaptation field
or the payload.
[0056] The demultiplexer 132 executes demultiplexing processing in
accordance with the channel-selecting control signal input from the
controller 30 via the remote controller interface 43 in response to
the program selected by the user by inputting a remote command. As
a consequence, the required packets including the MPEG-compressed
video signal, the MPEG-compressed audio signal, and the program
selection data or the limited reception data, and the service
information data, all of which represent the program selected by
the user, are separated and extracted.
[0057] FIG. 3 is a block diagram illustrating the demultiplexer
132. The demultiplexer 132 has a PID filter 321 and a section
filter 322. In the PID filter 321, based on the PID added to the
header of each transport packet, the MPEG-compressed video signal V
and the MPEG-compressed audio signal A of the program selected by
the user are extracted, and various data S concerning program
selection or limited reception is separated and extracted.
[0058] The video signal V and the audio signal A of the program
selected by the user are then supplied to the decoding unit 14.
Meanwhile, the data S is supplied to the section filter 322, and
the data, for example, the data concerning program selection or
limited reception, is separated and extracted. The data is then
supplied to the controller 30.
[0059] In the demultiplexer 132, a program clock reference, which
is used as a reference for reproducing the video signal and the
audio signal, is reproduced based on the synchronizing bit.
[0060] The decoding unit 14 is, as shown in FIG. 1, formed of an
MPEG decoder 141, a DRAM 142 used as a work area for MPEG-decoding
processing, a National Television System Committee (NTSC) encoder
143, and an audio signal digital-to-analog (D/A) conversion circuit
144.
[0061] As noted above, the video signal and the audio signal of the
program selected by the user are MPEG-compressed. Accordingly, the
MPEG decoder 141 decompresses the MPEG-compressed video signal and
the MPEG-compressed audio signal supplied from the demultiplexer
132. That is, the MPEG decoder 141 performs MPEG decoding.
[0062] The MPEG decoder 141 has an on-screen display (OSD) function
so that an EPG or a menu can be overlaid on an image of a target
program.
[0063] The decompressed video signal is then supplied to the NTSC
encoder 143, and is converted into an NTSC analog video signal. The
analog video signal is then supplied to a monitor receiver via an
external output terminal 15, and an image is displayed on the
screen of the monitor receiver.
[0064] Meanwhile, the decompressed audio signal is supplied to the
audio signal D/A conversion circuit 144, and is converted into an
analog audio signal. The analog audio signal is then supplied to a
speaker of the monitor receiver via an external output terminal 16,
and a sound is emitted from the speaker of the monitor
receiver.
[0065] According to this embodiment, the digital audio signal
(pulse code modulation (PCM) audio signal) decompressed in the MPEG
decoder 141 is supplied to the digital interface 20 through which
the digital audio signal or the transport stream can be provided to
external units.
[0066] The digital interface 20 forms output data from the data
processed by the receiving apparatus 3 of the first embodiment. The
digital interface 20 then transmits the output data to a digital
external unit via an input/output terminal 20T, and also receives
data input from the digital external unit via the input/output
terminal 20T in such a manner that the data can be processed in the
receiving apparatus 3. In this manner, according to the receiving
apparatus 3 of the first embodiment, the digital interface 20
serves as an interface for outputting a digital signal to the
digital external unit from the receiving apparatus 3 and for
inputting a digital signal into the receiving apparatus 3 from the
digital external unit.
[0067] According to the receiving apparatus 3 of the first
embodiment, the input/output terminal 20T is an IEEE1394
input/output terminal, which is an interface standard defined by
Institute of Electrical and Electronics Engineers (IEEE). Through
this input/output terminal 20T, digital data can be input into and
output from digital external units, such as a DVTR, a hard disk
drive unit for recording and reproducing digital video signals and
digital audio signals (hereinafter referred to as the "AVHDD
unit"), and an MD unit.
[0068] Supplied to the digital interface 20 are, as discussed
above, a multi-program transport stream including an
MPEG-compressed video signal and an MPEG-compressed audio signal of
a plurality of broadcast programs supplied from the descrambler 31,
and a digital audio signal of a single broadcast program separated
and extracted from the transport stream by the demultiplexer 132
and decompressed by the MPEG decoder 141.
[0069] The digital interface 20 of the receiving apparatus 3
outputs either the transport stream or the digital audio signal to
the external unit via the input/output terminal 20T under the
control of the controller 30 in response to the user's instruction.
In the first embodiment, the type of digital signal to be output is
selected in accordance with the external unit specified by the
user.
[0070] As noted above, digital units, such as a DVTR, an AVHDD
unit, an MD unit, etc., can be connected to the receiving apparatus
3 of the first embodiment via the input/output terminal 20T.
Accordingly, the user of the receiving apparatus 3 operates, for
example, a remote commander to supply to the receiving apparatus 3
command information for specifying the digital external unit as a
remote command signal.
[0071] Upon receiving the command information for specifying the
external unit, the controller 30 of the receiving apparatus 3
controls the digital interface 20 in response to the command signal
to supply the digital data in accordance with the selected digital
external unit via the input/output terminal 20T.
[0072] In the first embodiment, the receiving apparatus 3 supplies
a transport stream to the DVTR or the AVHDD unit, and supplies an
MPEG-decoded digital audio signal of a single broadcast program to
the MD unit.
[0073] It is now assumed that the input/output terminal 20T of the
receiving apparatus 3 of the first embodiment is connected to the
digital input terminal of a DVTR via an IEEE interface cable. When
the user specifies the DVTR as the digital external unit, as
discussed above, the digital interface 20 is operated as
follows.
[0074] Under the control of the controller 30, the digital
interface 20 converts the transport stream output from the
descrambler 131 to digital data so that the data can be output via
the IEEE1394 interface cable. The digital interface 20 then outputs
the digital data to the DVTR via the input/output terminal 20T.
This enables the DVTR to record on a vide tape the transport stream
supplied from the receiving apparatus 3 of the first
embodiment.
[0075] It is now assumed that the input/output terminal 20T of the
receiving apparatus 3 of the first embodiment is connected to the
digital input terminal of the DVTR via an IEEE interface cable.
When the user designates the DVTR as the digital external unit so
as to input a transport stream recorded on a video tape loaded into
the DVTR into the receiving apparatus 3 of the first embodiment,
the digital interface 20 is operated as follows.
[0076] Digital data having a format of the transport stream
compliant with the IEEE1394 standard has been input from the DVTR
via the IEEE1394 interface cable and the input/output terminal 20T.
Under the control of the controller 30, the digital interface 20
converts such digital data into digital data having a format that
can be processed by the receiving apparatus 3, and then supplies it
to the demultiplexer 132.
[0077] Upon receiving the transport stream, the demultiplexer 132
separates and extracts a video signal and an audio signal of a
target program from the transport stream, and performs a set of
processing, such as MPEG decoding, on the signals. Thus, an image
and a sound of the target program can be output and audio-visually
observed through the monitor receiver.
[0078] FIG. 4 illustrates the operation of the digital interface 20
performed when the user specifies an AVHDD unit as the digital
external unit, as discussed above. In FIG. 4, the input/output
terminal 20T of the receiving apparatus 3 is connected to the
digital input terminal of the AVHDD unit via an IEEE interface
cable. FIG. 4 shows essential portions of the receiving apparatus 3
of the first embodiment, i.e., the transport unit 13, the decoding
unit 14, the controller 30, and an AVHDD unit 200 connected to the
digital interface 20 via the IEEE1394 interface cable.
[0079] As described above, a transport stream output from the
descrambler 131 and an MPEG-decoded digital audio signal of a
single broadcast program from the MPEG decoder 141 are supplied, as
shown in FIG. 4, to the digital interface 20 of the receiving
apparatus 3.
[0080] When the user specifies the AVHDD unit 200 as the external
unit, the digital interface 20 converts, under the control of the
controller 30, the transport stream from the descrambler 131 into
digital data that can be output via the IEEE1394 interface cable.
The digital interface 20 then outputs the converted digital data to
the AVHDD unit 200 via the input/output terminal 20T. This enables
the AVHDD unit 200 to record on a hard disk (HDD) the transport
stream supplied from the receiving apparatus 3 of the first
embodiment.
[0081] It is now assumed that the input/output terminal 20T of the
receiving apparatus 3 is connected to the digital output terminal
of the AVHDD unit 200 via an IEEE interface cable. When the user
designates the AVHDD unit 200 as the digital external unit so as to
input a transport stream recorded on a hard disk of the AVHDD unit
into the receiving apparatus 3 of the first embodiment, the digital
interface 20 is operated as follows.
[0082] Digital data having a format of the transport stream
compliant with the IEEE1394 standard has been input from the AVHDD
unit 200 via the IEEE1394 interface cable and the input/output
terminal 20T. Under the control of the controller 30, the digital
interface 20 converts such digital data into digital data having a
format that can be processed by the receiving apparatus 3, and then
supplies the converted data to the demultiplexer 132.
[0083] Upon receiving the transport stream, the demultiplexer 132
separates and extracts a video signal and an audio signal of a
target program from the transport stream, and performs a set of
processing, such as MPEG decoding, on the signals. Thus, an image
and a sound of the target program can be output and audio-visually
observed through the monitor receiver.
[0084] As described above, according to this embodiment, it is
possible to supply transport streams to the DVTR and the AVHDD unit
200 and to record them on recording media. It is also possible to
supply to the receiving apparatus 3 transport streams recorded on
recording media with the DVTR and the AVHDD unit 200 and to
reproduce the transport streams.
[0085] FIG. 5 illustrates the operation of the digital interface 20
performed when the user specifies an MD unit 300 as the digital
external unit, as discussed above. In FIG. 5, the input/output
terminal 20T of the receiving apparatus 3 is connected to the
digital input terminal of the MD unit 300 via an IEEE interface
cable. FIG. 5 shows essential portions of the receiving apparatus 3
of the first embodiment shown in FIG. 1, i.e., the transport unit
13, the decoding unit 14, the controller 30, and the MD unit 300
connected to the digital interface 20 via the IEEE1394 interface
cable.
[0086] Among a transport stream from the descrambler 131 and an
MPEG-decoded digital audio signal of a single broadcast program
from the MPEG decoder 141, the digital interface 20 selects and
outputs the MPEG-decoded digital audio signal from the MPEG decoder
141 under the control of the controller 30. More specifically, the
digital interface 20 converts the MPEG-decoded digital audio signal
(PCM audio signal) supplied from the MPEG decoder 141 into a
digital audio signal which is in compliance with the IEC958
standard defined by the International Electrotechnical Commission
(IEC) and which can be output via the IEEE1394 interface cable. The
digital interface 20 then outputs the converted audio signal to the
MD unit 300 via the input/output terminal 20T.
[0087] This enables the MD unit 300 to record on an MD the
MPEG-decoded digital audio signal of a single broadcast program
supplied from the receiving apparatus 3 of the first embodiment.
The digital audio signal recorded on the MD is then reproduced with
the MD unit 300 and audibly output via, for example, headphones
connected to the MD unit 300.
[0088] That is, it is possible to record on an MD only the sound
of, for example, a music program, or an education program, such as
for languages, demodulated by the receiving apparatus 3 of the
first embodiment, and to easily reproduce the recorded sound with
the MD unit 300. A digital audio signal supplied from the MD unit
300 can be input into the receiving apparatus 3 of the first
embodiment via the digital interface 20, and can be D/A-converted
and output.
[0089] It is now assumed that the input/output terminal 20T of the
receiving apparatus 3 is connected to the digital output terminal
of the MD unit 300 via an IEEE interface cable. When the user
designates the MD unit 300 as the digital external unit so as to
input a digital audio signal recorded on an MD of the MD unit into
the receiving apparatus 3, the digital interface 20 is operated as
follows.
[0090] A digital audio signal which can be input and output via an
IEEE1394 interface cable and which is in compliance with the IEC958
standard defined by the IEC has been input from the MD unit 300 via
the IEEE1394 interface cable and the input/output terminal 20T.
Under the control of the controller 30, the digital interface 20
converts such a digital audio signal into a digital audio signal
having a format that can be processed by the receiving apparatus 3.
The digital audio signal is then supplied, as shown in FIG. 5, to
the audio signal D/A converter 144.
[0091] In the audio signal D/A converter 144, the digital audio
signal is converted into an analog audio signal, which is then
supplied to a speaker via an AV amplifier and a monitor receiver.
Sound is then emitted from the speaker.
[0092] In this manner, the MPEG-decoded digital audio signal
recorded on an MD loaded into the MD unit 300 is converted into an
analog audio signal by the receiving apparatus 3, and is then
supplied to a speaker via an AV amplifier. As a consequence, sound
contained in the digital audio signal recorded on the MD unit 300
can be emitted.
[0093] A description is now given, with reference to the flow chart
of FIG. 6, of the operation of the receiving apparatus 3 of the
first embodiment performed when digital data is output via the
digital interface 20.
[0094] As discussed above, digital external units, such as a DVTR,
an AVHDD unit, an MD unit, etc., can be connected to the receiving
apparatus 3 of the first embodiment via the input/output terminal
20T and the digital interface 20.. The digital external unit is
selected so that digital data in accordance with the selected
digital external unit can be supplied to and received from the
receiving apparatus 3.
[0095] According to the receiving apparatus 3 of the first
embodiment, when the user operates the remote commander provided
for the receiving apparatus 3 to select the digital external unit
to which digital data is to be supplied or from which it is to be
received, the controller 30 starts the processing shown in FIG.
6.
[0096] More specifically, upon receiving the operation for
selecting the external unit to or from which digital data is to be
supplied or received, the controller 30 displays an EPG, based on
the EPG data obtained from the transport stream, by using the OSD
function provided for the MPEG decoder 141 (step 101). The
controller 30 waits for a program contained in the transport stream
to be selected and input (step 102).
[0097] Subsequently, the controller 30 controls the demultiplexer
132 to select the program based on the program selected by the user
(step 103). The controller 30 then displays a list of digital
external units to be selected (step 104). The display of the list,
as well as the display of the EPG, is performed by using the OSD
function provided for the MPEG decoder 141. In the first
embodiment, as noted above, a list of external units, such as a
DVTR, an AVHDD unit, and an MD unit, to be selected, is
displayed.
[0098] Thereafter, the controller 30 waits for the digital external
unit to be selected (step 105), and determines which type of
digital external unit has been selected (step 106).
[0099] If it is determined in step 106 that the user has selected
the DVTR, the controller 30 controls the digital interface 20 to
output the transport stream from the descrambler 131 via the
input/output terminal 20T (step 107).
[0100] If it is determined in step 106 that the user has selected
the AVHDD unit, the controller 30 controls the digital interface 20
to output the transport stream from the descrambler 131 via the
input/output terminal 20T in a manner similar to the processing of
step 107 (step 108).
[0101] If it is found in step 106 that the user has selected the MD
unit, the controller 30 controls the digital interface 20 to output
the MPEG-decoded digital audio signal of a single broadcast program
from the MPEG decoder 141 via the input/output terminal 20T (step
109).
[0102] As described above, according to the receiving apparatus 3
of the first embodiment, digital data to be output can be switched
in accordance with the type of digital external unit connectable to
the receiving apparatus 3 via the external input terminal 20T and
the digital interface 20 and selected by the user. Further, when
digital data is to be input from the digital external unit via the
input/output terminal 20T and the digital interface 20, the digital
data is processed in accordance with the selected digital external
unit.
[0103] More specifically, according to the receiving apparatus 3 of
the first embodiment, when information is to be reproduced from
digital data by a digital external unit and output to the receiving
apparatus 3, processing is performed in a manner similar to the
processing executed when digital data is output to the digital
external unit, as described above with reference to FIG. 6. That
is, a list of digital external units to be selected is displayed so
that the digital external unit to supply the digital data to the
receiving apparatus 3 can be selected by the user.
[0104] If the user selects the DVTR or the AVHDD unit, the
controller 30 determines that digital data to be input complies
with the format of the transport stream. The controller 30 then
controls the digital interface 20 to receive the transport stream
from the DVTR or the AVHDD unit, as discussed above, and supplies
the received transport stream to the demultiplexer 132.
[0105] If the user selects the MD unit as the digital external
unit, the controller 30 determines that digital data to be input
represents an MPEG-decoded digital audio signal of a single
broadcast program. The controller 30 then controls the digital
interface 20 to receive the digital audio signal from the MD unit,
and supplies it to the audio signal D/A converter 144.
[0106] Thus, no matter which digital external unit supplies digital
data, processing can be suitably performed in accordance with the
digital data, and information can be reproduced from the digital
data and be output.
[0107] According to the receiving apparatus 3 of the first
embodiment, as described above, digital data to be output can be
switched in accordance with the type of digital external unit
connected to the receiving apparatus 3 via the digital interface 20
and the input/output terminal 20T and selected by the user.
Additionally, the receiving apparatus 3 can receive and process
digital data in accordance with the digital external unit which
supplies the digital data.
[0108] In particular, concerning digital data to be output, not
only digital data in the format of the transport stream, but also
an MPEG-decoded digital audio signal of a single broadcast program
can be output.
[0109] Accordingly, when an MPEG-decoded digital audio signal of a
single broadcast program is supplied from the receiving apparatus 3
and is recorded on a recording medium by using the MD unit, the
recorded digital data is not required to be MPEG-decoded when being
reproduced. Thus, the digital data supplied from the receiving
apparatus 3 can be directly reproduced and utilized without needing
to be input into the receiving apparatus 3 again. That is,
broadcast programs provided by digital broadcasting can be utilized
more effectively.
[0110] In the first embodiment, the video signal and the audio
signal of a program provided by digital broadcasting are compressed
according to the MPEG method. However, signals compressed according
to a method other than the MPEG method may be supplied.
[0111] It may be considered, for example, that an audio signal
compressed according to the Adaptive Transform Acoustic Coding
(ATRAC) method is provided by digital broadcasting. In the ATRAC
method, the audible masking effect of humans is utilized to select
major sound components and eliminate unnecessary sound components
so as to compress audio signals. Audio signals of music programs,
for example, may be compressed according to the ATRAC method and be
broadcast.
[0112] If the audio signal compressed according to the ATRAC method
is provided by digital broadcasting, as discussed above, a
transport packet containing the ATRAC-compressed audio signal is
extracted in the demultiplexer 132 of the receiving apparatus 3.
The extracted transport packet is then supplied to the controller
30 via the bus 31 and is temporarily stored in the DRAM 33 of the
controller 30.
[0113] By the controller 30, the ATRAC-compressed audio signal is
extracted from the transport packet temporarily stored in the DRAM
33. The extracted audio signal is then supplied to the digital
interface 20 via the bus 31.
[0114] The digital interface 20 is provided with a decompression
function of decompressing ATRAC-compressed audio signals, and the
ATRAC-compressed audio signal supplied from the controller 30 is
then decompressed and is output.
[0115] According to the first embodiment, it is thus possible to
decompress the ATRAC-compressed audio signal and to provide it to a
digital external unit, for example, an MD unit, an AVHDD unit, or a
DVTR.
[0116] Alternatively, a software decoder compatible with the ATRAC
method and executable by the controller 30 may be stored in the
program ROM 34, and the ATRAC-compressed audio signal may be
decompressed by using the software decoder and be provided to a
digital external unit, such as an MD unit.
[0117] The ATRAC-compressed audio signal can be directly output
from the digital interface 20 via the input/output terminal 20T
without being decompressed. This is effective for external units,
such as MD units, that can receive ATRAC-compressed audio signals
and directly record them on a recording medium.
[0118] To reproduce ATRAC-compressed audio signals, an ATRAC
decoder, which is a decompression function for decompressing
ATRAC-compressed audio signals, may be provided for the decoding
unit 14 of the receiving apparatus 3. Then, the ATRAC-compressed
audio signals can be reproduced by the receiving apparatus 3.
[0119] Alternatively, the receiving apparatus 3 may not be provided
with an ATRAC decoder and directly provide ATRAC-compressed audio
signals by digital broadcasting. Accordingly, the audio signals are
received, but cannot be utilized before they are recorded on a
recording medium with, for example, an MD unit. That is, it is
possible to provide a new provision form of audio signals by using
digital broadcasting.
[0120] The transport stream includes, as discussed above, not only
video signals and audio signals of broadcast programs, but also
data, such as, what is called, homepages and game programs. That
is, in digital television broadcasting, not only television
broadcast programs, but also content data, such as homepages and
game programs can be broadcast. Such data utilized by the user, as
well as the above-described ATRAC-compressed audio signals, is
extracted by the demultiplexer 132, and is then supplied to the
controller 30 via the bus 31 and further to the digital interface
20 via the controller 30.
[0121] The user data, such as homepages and game programs, provided
by digital broadcasting, can be supplied to the digital external
unit, for example, a DVTR, an AVHDD unit, or an MD unit, via the
input/output terminal 20T from the digital interface 20, and can be
recorded on a recording medium with the digital unit.
[0122] As described above, transport streams are supplied to the
DVTR or the AVHDD unit from the receiving apparatus 3.
Alternatively, either of the transport stream, or digital data,
such as content information, to be supplied from the demultiplexer
132 via the controller 30, may be selected. As a result, the
content information, as well as the transport streams, can be
recorded on a recording medium with the DVTR or the AVHDD unit.
[0123] That is, the user data, such as content information,
provided by digital television broadcasting, can be supplied to a
digital external unit via the digital interface 20, and be recorded
on a recording medium. The user data recorded on the recording
medium can also be reproduced with the use of the digital external
unit and be utilized.
[0124] Second Embodiment
[0125] FIG. 7 is a block diagram illustrating a digital broadcast
receiving apparatus 4 according to a second embodiment of the
present invention. The digital broadcast receiving apparatus 4 of
the second embodiment, as well as the receiving apparatus 3 of the
first embodiment described with reference to FIG. 1, includes a
received-signal processor 10, and a controller 30 to which a modem
41, an IC card interface 42, a remote commander interface 43, and a
main-unit display interface 44 are connected. The received-signal
processor 10 and the controller 30 are constructed similarly to
those of the receiving apparatus 3 of the aforementioned first
embodiment.
[0126] More specifically, a target carrier is selected from
intermediate frequency signals supplied via the received-signal
processor 10, an antenna 1, a converter 2, and an input terminal
4in. From the selected carrier, a transport stream in which a
plurality of broadcast program signals are multiplexed is obtained.
Then, a target broadcast program signal is extracted from this
transport stream, and the extracted signal is decompressed and D/A
converted so that an analog output video signal and an analog
output audio signal can be formed and output. The controller 30
serves to control the individual elements of the receiving
apparatus 4.
[0127] The receiving apparatus 4 of the second embodiment has a
plurality of digital interfaces 21 through 23 and input/output
terminals 21T through 23T corresponding to the respective digital
interfaces 21 through 23, so that a plurality of digital external
units can be simultaneously connected to the receiving apparatus
4.
[0128] When a digital external unit is connected to one of the
input/output terminals 21T through 23T, the controller 30 of the
receiving apparatus 4 is adapted to identify what type of digital
unit is connected to which input/output terminal.
[0129] The receiving apparatus 4 of the second embodiment is, as
shown in FIG. 7, configured as follows. When a DVTR 100', an AVHDD
unit 200, and an MD unit 300 are simultaneously connected to the
receiving apparatus 4, the connected digital units can be
designated. Then, the digital interfaces 21 through 23
corresponding to the designated digital units are controlled to
supply or receive digital data to or from the receiving apparatus
4.
[0130] FIG. 8 is a flow chart illustrating the operation performed
when digital data is output via the digital interfaces 21 through
23 in the receiving apparatus 4 of the second embodiment.
[0131] According to the receiving apparatus 4 of the second
embodiment, as well as the receiving apparatus 3 of the
aforementioned first embodiment, when the user operates a remote
commander provided for the receiving apparatus 4 so as to select
the external unit to which digital data is supplied or from which
it is received, the controller 30 starts the processing shown in
FIG. 8.
[0132] In the flow chart illustrated in FIG. 8, processing of steps
201 through 203 are similar to processing of steps 101 through 103
performed by the receiving apparatus 3 of the first embodiment
described with reference to FIG. 6.
[0133] Subsequent to the display of an EPG (step 201), the input of
selecting a program (step 202), and the execution of selecting a
program (step 203), the controller 30 displays a list of digital
external units to be selected in accordance with the digital
external units connected to the receiving apparatus 4 of the second
embodiment (step 204).
[0134] When digital external units are connected to the
input/output terminals 21T through 23T, as noted above, the
controller 30 of the receiving apparatus 4 is able to identify
which type of external unit is connected to which input/output
terminal.
[0135] Then, in step 204, the controller 30 displays a list of
digital external units connected to the receiving apparatus 4. The
display of the list, as well as the display of the EPG, is
performed by using the OSD function of the MPEG decoder 141.
[0136] Subsequently, the controller 30 receives the input of
selecting a digital external unit from the list of digital external
units (step 205), and then identifies the type of selected digital
external unit (step 206).
[0137] The controller 30 then controls one of the digital
interfaces 21, 22, and 23 connected to the selected digital
external unit to output digital data to the selected digital
external unit (step 207).
[0138] If the selected digital external unit is the DVTR 100 or the
AVHDD unit 200, the controller 30 controls the digital interface
connected to the selected digital external unit to output a
transport stream from the descrambler 131 to the digital external
unit.
[0139] In the embodiment illustrated in FIG. 7, when the DVTR 100
is selected, the controller 30 controls the digital interface 21 to
supply a transport stream from the descrambler 131 to the DVTR 100.
When the AVHDD unit 200 is selected, the controller 30 controls the
digital interface 22 to supply a transport stream from the
descrambler 131 to the AVHDD unit 200.
[0140] When the selected digital external unit is the MD unit 300,
the controller 30 controls the digital interface 23 connected to
the MD unit 300 to output an MPEG-decoded digital audio signal of a
single broadcast program from the MPEG decoder 141 to the MD unit
300.
[0141] That is, in the embodiment shown in FIG. 7, when the MD unit
300 is selected, the controller 30 controls the digital interface
23 to supply a digital audio signal from the MPEG decoder 141 to
the MD unit 300.
[0142] In this manner, the receiving apparatus 4 of the second
embodiment, as well as the receiving apparatus 3 of the first
embodiment, can switch digital data to be output in accordance with
the external unit connected to the receiving apparatus 4 and
selected by the user.
[0143] Any of the DVTR 100, the AVHDD unit 200, and the MD unit 300
can be connected to the input/output terminals 21T through 23T.
Accordingly, no matter which digital external unit is connected to
any input/output terminal, digital data can be supplied to and
received from the digital unit selected by the user.
[0144] In the second embodiment, transport streams are supplied to
the DVTR 100 or the AVHDD unit 200, while MPEG-decoded digital
audio signals are supplied to the MD unit 300. However, this is not
exclusive.
[0145] Transport streams from the descrambler 131 and decompressed
digital audio signals of a single broadcast program from the MPEG
decoder 141 are supplied, as shown in FIG. 7, to each of the
digital interfaces 21, 22, and 23. Accordingly, a modification is
made, for example, so that a transport stream and an MPEG-decoded
digital audio signal may be supplied to each of the DVTR 100 and
the AVHDD unit 200, and the user may select the transport stream or
the digital audio signal to be output.
[0146] That is, digital data supplied from the receiving apparatus
of the present invention via the digital interface may be selected
according to the purpose of the use of the digital external unit to
be connected or the capacity or the function of a recording medium
for use in the digital external unit.
[0147] According to the receiving apparatus 4 of the second
embodiment, as well as the receiving apparatus 3 of the first
embodiment, digital audio signals compressed by, for example, the
ATRAC method, and content data, such as what is called, homepages
and game programs, can be output to external units via the
controller 30 and the digital interfaces 21, 22, and 23.
[0148] Moreover, digital data having a format of the transport
stream which is input from a digital external unit may be supplied
to the demultiplexer 132 via each of the digital interfaces 21, 22,
and 23, and a decompressed digital audio signal input from a
digital external unit may be supplied to the audio signal D/A
converter 144.
[0149] This makes it possible to receive digital data and suitably
process it in accordance with the digital external unit that is to
supply the data. That is, digital data having a format of the
transport stream and decompressed digital audio signals can be
received and reproduced and output.
[0150] In the foregoing first and second embodiments, transport
streams and MPEG-decoded digital audio signals, or content data are
supplied to the digital interfaces. This is not, however,
exclusive. MPEG-decoded digital video signals may be supplied to
the digital interfaces, for example, MPEG-decoded digital video
signals and MPEG-decoded digital audio signals of a single
broadcast program may be supplied to the DVTR and the AVHDD unit.
In this case, since the MPEG-decoded digital video signals contain
a large amount of data, the transmission rate can be increased to
implement this modification.
[0151] In the foregoing first and second embodiments, as external
units connectable to the digital broadcast receiving apparatus, a
DVTR, an AVHDD unit, and an MD unit are used. However, various
types of digital units for recording and reproducing digital data
on and from recording media may be used. For example, a digital
video disk (DVD) unit for recording and reproducing digital data on
and from a DVD, which serves as a recording medium, a floppy disk
unit using a floppy disk as a recording medium, and a CD-ROM unit
using a rewritable CD-ROM as a recording medium, may be connected
to the receiving apparatus of the present invention.
[0152] In the digital broadcast receiving apparatuses of the
respective first and second embodiments, a digital broadcast in
which a plurality of broadcast program signals are multiplexed on a
single carrier is received and processed. The present invention is,
however, applicable to a digital broadcast in which a single
broadcast program signal is carried on a single carrier.
[0153] More specifically, a single broadcast program signal carried
on a single carrier may be received and demodulated. Then, the
demodulated signal and a signal obtained by decompressing this
demodulated signal may be supplied to the digital interface and be
output to the external unit according to the user's
instruction.
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