Note: Descriptions are shown in the official language in which they were submitted.
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~ET~OD AND APPARATUS FOR SORTING
~NN~T- GUIDES BASED ON C~LL SIGN
R~R~OUND OF THE l~v~.. lON
1. Field of the Invention
The present invention relates generally to a subscription
television system, and more particularly, to a method and
apparatus for sorting channel guides based on ~he call sign of
the various channels.
2. Description of the Prior Art
As the subscription television industry has grown, providers
of subscription television continually offer more and more
channels to the individual subscriber. Typical systems of~er
more than 100 di~ferent channels. Such systems also typically
display a channel or program guide, which identifies all
available channels and the programs currently airing and upcoming
programs on the associated channel.
In known systems, for example, the system described in U.S.
Patent No. 5,353,121, which is herein incorporated by re~erence,
the channel guide is sorted by channel number. In other words,
channel no. 1 and the associated program is listed first in the
guide, then channel no. 2 is listed, and so on. However, each
subscription television provider is responsible for assigning a
given channel ~e.g., 1, 2, 3, etc.) to a program source (e.g.,
TNN, MTV, CNN, etc.). As such, the channel number corresponding
to a given program source varies from provider to provider.
Thus, a substantial problem arises for the individual
subscriber in that the subscri~er may have to scan over 100
channels in the program guide in order to locate the desired
program source (e.g., ABC). Due to the numerous channels
available, this searching can re~uire a considerable amount o~
time. Furthermore, even once the desired channel is initially
located, it becomes a significant mental challenge to recall the
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numerical designations associated with the numerous program
sources of interest, withou~ returning and scanning through the
program guide once again.
Accordingly, there exists a need for a program guide which
allows the subscriber to readily locate the desired program
source without the need for sc~nn;ng the entire program guide.
SUMMaRY OF THE l~V~'l'10~
The present invention provides a program guide which
satisfies the aforementioned needs. Specifically, the present
invention provides a program guide which lists ~he available
program sources in alphabe~ical order.
The present invention relates generally to a terminal device
for use with a receiver having a display screen. The terminal
device comprises means for receiving a signal containing program
source information and program event information for a plurality
of program sources (i.e., the program guide), memory means
coupled to the receiving means for storing the program guide,
display means for outputting the program guide to the display
screen and a system controller coupled to the memory means and
the display means. The system controller functions to control
the transfer of the program guide between the memory means and
the display means such that the plurality of program sources are
listed in alphabetical order in the program guide.
The present invention also relates to a method of~generating
a program guide. The method comprises receiving a signal
containing program source information and program event
information for a plurality of program sources, decoding the
signal so as to identify each program source and the
corresponding program event information for each program source,
and displaying the program source information and corresponding
program event information for each of the plurality of program
sources on the display screen such that the plurality of program
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sources are listed in alphabetical order.
As described in detail below, the method and apparatus of
the present invention provide important advantages. Most
importantly, the present invention eliminates the need for the
subscriber or viewer to scan over the entire range of available
channels in order to locate a desired program source.
Furt~ermore, the present invention eliminates the need for the
subscriber ~o memorize the numerical designation (which may
change from system to system) associated with a given program
source.
The invention itself, together with further objects and
attendant advantages, will best be understood by re~erence to the
following detailed description, taken in conjunction with the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig.-1 is a functional block diagram of one embodiment of
the terminal device of the present invention.
~ig. 2 illustrates an exemplary program guide produced in
accordance with the present invention.
DET~TT.~ DESCRIPTION OF THE DRAWINGS
Fig. 1 is a functional block diagram of one embodiment of
the terminal device 10 of the present invention. As shown in
Fig. 1, the terminal device lo includes receiving means 11
comprising tuner 12, demodulator 13 and FEC decoder 14. The
receiving means 11 is controlled by microprocessor 15, and
operates to receive a signal which includes program guide, and
video and audio information for all channels available on the
given system.
In the embodiment of Fig. 1, an antenna 8 and low noise
filter 9 function to receive the signal from a satellite source
and to couple the signal to the receiving means 11 of the
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terminal device 10. However, it is noted that the present
invention is not limited-to system providers which utilize
satellite tr~n~ sions to broadcast signals. The novel system
of the present invention could be readily used with system
providers who supply signals via, for example, cable or telephone
lines.
Upon receipt of the signal, tuner 12 functions to
downconvert the received signal to an intermediate fre~uency
("IF"). The IF signal is then converted to a digital equivalent
by the demodulator 13 and coupled to decoder 14, which provides
forward error correction on the received signal.
~ ppaxatus 10 also comprises a transport chip 11. The
transport chip 11 preferably comprises a channel demultiplexer
16, a decryption unit 17 and an access card interface 1~. The
output of the decoder 14 is coupled to the channel demultiplexer
16, which functions to separate the audio and video information
of each channel, and also separates the program guide
information. Under control o~ the microprocessor 15, the channel
demultiplexer 16 provides at its output port, the audio and video
information of a selected channel or the program guide
information.
Transport chip 11 further comprises an access card reader 19
which is coupled to the decryption unit 17 and the access card
interface 18. The access card interface 18 operates in
conjunction with the decryption unit 17 and the access~card
reader 19 to provide a means of preventing, for example,
unauthorized pay-per-view movies from being ordered by children.
Apparatus 10 ~urther comprises a modem 31 which allows the
microprocessor 15 to be coupled to, for example, the public
telephone network. The apparatus also includes microprocessor
peripherals 33, such as serial and/or parallel data ports, and a
power supply 35 for supplying power.
In the satellite system illustrated in Fig. 1, multiple
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transponders located in a satellite (not shown) are utilized to
transmit channel information (e.g., audio, video) to the terminal
device 10. Each transponder transmits information regarding
multiple channe~s ~i.e., multiple program sources, such as ABC,
CBS, etc.). However, each transponder also transmits the program
guide for every channel provided by the system provider on one of
the frequencies available within the given transponder.
As such, regardless of which transponder the tuner 12 is
tuned to, the program guide is available at the output of the
channel demultiplexer 16. Under control of the microprocessor
15, the program guide is stored in random access memory ( IIRAMII )
20, which is coupled to the channel demultiplexer 16. The system
RAM 20 also ~unctions to buffer the digital data associated with
the audio and video data of a given channel.
The microprocessor 15 operates to periodically update the
program guide stored in the system RAM 20. In the present
embodiment, the program guide is updated one of two ways. First,
the microprocessor 15 periodically analyzes the program guide
transmitted by the provider to determine if the program guide has
been updated. This can be accomplished, for example, by
utilizing a flag bit which indicates that the program guide has
heen modified. If the program guide has been modified, the
microprocessor 15 stores the updated guide in the system RAM 20.
Second, as an independent process, the microprocessor 15 monitors
an expiration date/time transmitted along with the program guide.
Upon reaching the expiration date/time, the microprocessor 15
updates the program guide stored in system RAM 20 with the
program guide currently being transmitted.
Returning to Fig. 1, the terminal device of the present
invention further comprises a MPEG chip 22, for example, Part No.
64002, manufactured by LSI ~ogic. The MPEG chip 22 comprises a
video decoder and on screen display ~enerator 24, and an audio
decoder 25. The MPBG chip 22 functions to decompress the audio
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and video data output by the channel demultiplexer 16, which is
transmitted by the provider in a compressed format. The NTSC
encoder 26 and audio subsystem 27 format the decompressed audio
and video data, respectively, for display on, for example, a
television receiver~ The ~uL~u~ drivers 28 function to transmit
the audio and video information of a selected channel to the
display screen of the television receiver.
In the event the subscriber selects to display the program
guide, which can be accomplished by selecting the predefined
channel associated with the program guide, via front panel 30,or
a remote control (not shown), the microprocessor 15 retrieves the
program guide from system RAM 20, and then accesses a font table
stored in memory. The microprocessor 15 then converts the
program guide stored in memory 20 into a displayable font data.
The displayable font data is then coupled to the MPEG chip 22.
As described above, the MPEG chip 22 in combination with NTSC
encoder 26 and the output drivers 28, functions to write the
program guide to the television receiver at the start of the next
available frame.
Importantly, when providing the displayable font information
to the MPEG chip 22, the microprocessor 15 arranges the program
guide such that the program source in~ormation (e.g., ABC, TNN,
CNN, etc.) is displayed on the television receiver in
alphabetical order.
Fig. 2 illustrates an exemplary program guide pro~duced in
accordance with the present invention. As shown in Fig. 2, the
program guide is presented in alphabetical order ~ased on program
source (i.e., call sign). The terminal device o~ the present
embodiment is capable of displaying approximately seven program
sources and the corresponding programs at a single time. As
shown in Fig. 2, the program source and the programs being shown
thereon are displayed on a single line comprising multiple cells
of varying length. The first cell indicates the program source
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and the channel number assigned to the source. In the present
embodiment, the program sources are listed alphabetically from
top to bottom. However, the reverse is also possible. In order
~o view additional program information, the subscriber simply
presses, for example, a page down key or a scroll key, on the
remote control (i.e., scroll down key) and the foregoing process
is repeated for the new program data to be displayed.
The alphabetical ordering of the program source information
can be accomplished in numerous ways. For example, prior to
initially storing the program guide in system RAM 20, the
microprocessor 15 can be programmed to analyze and identify all
program sources contained within the program guide, and
thereafter store the program guide in system memory 20 in an
alphabetical order based on program source. As such, when
subsequently transferring data to the MPEG chip 22, the
microprocessor 15 need only transfer program guide entries stored
in the system RAM 20 in a sequential fashion in order to maintain
and present the program sources in an alphabetical order.
Alternatively, the microprocessor 15 can be commanded to
alphabetize the program guide on the basis of program source
subsequent to the program guide initially being stored in system
RAM 20. This can be accomplished by indexing the program guide
stored in memory. Specifically, once stored, each program source
is identified and indexed so as create an alphabetical ordering
of the program sources. Indexing the program sources can entail,
for example, providing pointers to each program source such that
upon generation of the guide by accessing the pointers, the guide
is generated in alphabetical order. Of course other methods of
generating the alphabetical ordering is possible.
The two foregoing methods of generating a program guide
which displays the program sources in alphabetical order are only
exemplary of the numerous methods available. In the present
embodiment of the terminal device 10, it should be remembered
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that the program guide must be supplied to the MPEG chip 22 in
the order to be displayed. It is also understood that various
methods are available for mapping the program source information
with the corresponding program event information in memory 20.
The method and apparatus of the present invention provides
important advantages. Most importantly, ~he present invention
eliminates the need for the subscriber or viewer to scan over the
entire range of available channels in order to locate a desired
program source. Furthermore, the present invention eliminates
the need for the subscriber to memorize the numerical designation
(which changes from system to system) associated with a given
program source.
Of course, it should be understood that a wide range of
changes and modifications can be made to the preferred embodiment
described above. It is therefore intended that the foregoing
detailed description be regarded as illustrative rather than
limiting and that it be understood that it is the following
claims, including all equivalents, which are intended to define
the scope of the invention.
