Note: Descriptions are shown in the official language in which they were submitted.
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1
FIELD OF THE INVENTION
TELEVISION PROGRAM GUIDE
This invention relates to a system and method for controlling the broadcast
and recording
of television programs and for distributing information to be displayed on a
television screen.
BACKGROUND OF THE INVENTION
There are many known systems for controlling the operation of a television and
a video
recorder and for providing information on a television screen. One of the
primary types of
information that is displayed to viewers is programming information which may
include current
program information as well as future program information. Viewers often have
a need to access
current and future schedule information and often that requires locating an
appropriate television
directory in either a newspaper or weekly magazine.
For many years, users have also encountered significant difficulties in
programming video
recorders. In recent years systems have been developed which simplify the
recording process so
that it is easier for a user to program. These systems (for example, the VCR+
system), however,
require that the user locate program listings in some other source before he
or she can program
the VCR to record. If a program listing includes code information (termed
"plus codes"), the user
can use depress keys on a VCR+ infrared remote control device in a pattern
determined by the
code information to, in turn, program the VCR. The code information identifies
channel,
broadcast time and duration for a program that the user wishes to record. This
must be done for
each program to be recorded, and for each, for example, weekly episode.
In many known systems which provide programming information to the user, the
programming information is loaded at some periodic basis. Television stations,
however, often
change the programs that will be aired and there is no way for updating such
systems of last
minute programming changes. Therefore, if a user views programming information
on his
television and either sets a recorder to record the program or makes plans to
be able to watch a
program at a certain time and the station changes that programming
information, either the
wrong program will be recorded or the user would not be able to watch the
program that he
desired to watch.
In another system, called "Starlight", program information may be broadcast by
a
television broadcasting station on an interleaved basis while it is
broadcasting television
programs, in particular during a portion of the television signal termed the
"vertical blanking
interval." When the information is displayed, a program may be selected for
viewing or recording
by moving a highlight cursor to a program title on the display and depressing
a button on a
remote control device. However, it is not economical to guarantee that the
information is
available in the vertical blanking interval of every transmitted channel, so
this system generally
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1 cannot receive information updates while channels other than those carrying
the information
signal are being viewed.
SUMMARY OF THE INVENTION
The invention provides a new and improved system and method for controlling
the
broadcast and recording of television programs and for distributing
information to be displayed
on a television screen.
In brief summary, the new system includes a central broadcasting computer
which
receives television schedule and episode, news, sports and other information
from various
sources. The central broadcasting computer transmits this information over a
wide area network
to a multiplicity of radio transmitters covering a wide area, such as the
entire continental United
States. These transmitters transmit the information to individual set-top
boxes in homes and
businesses using a reserved nationwide pager frequency. Each set-top box
includes a CPU and
a memory means. The broadcast information is processed by the CPU and stored
in the memory
means until accessed by the user.
Each set-top box is configured so that the user may use a single,
ergonomically designed
user control device, such as an IR remote control to control his television
and external devices
(such as VCRs, video disk players, cable decoders and antennas). Using the
user control device,
the user can also cause the television to display the broadcast information in
various easy-to-
understand formats. Among these display screens are grids of television and
cable programming
organized by channel and time, news headlines and supporting information, and
up-to-date sports
scores and highlights. By selecting programs or other options from these
screens, the user may
cause the television to change channels to the desired program or may program
the VCR to
record certain programs. By selecting other menu options, the user may also
cause the television
to automatically be muted or switch to another channel during commercial
breaks, and to skip
commercial breaks when recording programs.
In a preferred embodiment, the RF transmitters broadcast information using the
nationwide pager bandwidth around 931 MHz. Information is encoded using any of
a number
of well-known transmission protocols, such as the POCSAG protocol or the
Motorola FLEX
protocol. The system includes a unique method of reducing noise and
interpreting broadcast data
in this format.
The. attainment of the foregoing and related objects, advantages and features
of the
invention should be more readily apparent to those skilled in the art after
review of the following
detailed description of the invention, which should be read in conjunction
with the
accompanying drawings.
DESCRIPTION OF THE DRAWINGS
This invention is pointed out with particularity in the appended claims. The
above and
further advantages of this invention may be better understood by referring to
the following
description taken in conjunction with the accompanying drawings, in which:
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1 FIG. 1 is a block diagram of the wide area system for transmitting
broadcasting
information of the present invention;
FIG. 2 is a block diagram of a pager terminal used in the system shown in FIG.
l;
FIG. 3 is a block diagram of the components of a set-top box used in the
system and
process of the present invention for providing information and for controlling
the operation of
a television and associated external devices;
FIG. 4 is a block circuit diagram of the RF receiver used in the set-box shown
in FIG. 3;
FIG. 5a is a block circuit diagram of the data deserialization module 74 shown
in FIG. 4;
FIG. 5b is a block circuit diagram of an alternate embodiment of the
comparator operation
used in the data deserialization module shown in FIG. 5a;
FIG. 6 is a block circuit diagram of the bit sampling module shown in FIG. 5a;
FIGs. 7a and 7b are representative signal samples processed by the bit
sampling module
of FIG. 5a;
FIG. 8 is another signal representation which is processed by the bit sampling
module
shown in FIG. 5a;
FIG. 9 is a flow chart of the operation of the CPU of the present invention
which provides
task scheduling. and communications facilities for the system;
FIG. 10 is a functional diagram of the information processed by the system of
the present
invention;
FIG. 11 is a data representation of a data record transmitted by the system of
the present
invention;
FIG.12 is a diagram illustrating the data flow in a particular application in
the system and
method of the present invention;
FIG.13 is a block diagram showing the relationship of various functional
components of
the system and process of the present invention used for displaying
information on a television
screen;
FIG. 14 is a flow chart showing the steps associated with a memory request
made by the
system and process of the present invention;
FIG. 15 is a functional diagram of the remote control used in the system of
the present
invention;
FIG. 16 is a representation of the main screen display generated by the system
of the
present invention;
FIG. 17 is a representation of a Navigation Screen generated by the system of
the present
invention;
FIG. 18 is a representation of a Program Grid screen generated by the system
of the
present invention;
FIG. 19 is a representation of a Sports Ticker screen generated by the system
of the
present invention;
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1 FIG. 20 is a representation of a News Screen generated by the system of the
present
invention;
FIG. 21 is a flowchart of the steps of the automatic recording process
utilized by the
system of the present invention;
FIG. 22 is a flowchart of the steps utilized by the system of the present
invention for
implementing the "While recording" commercial avoidance feature;
FIG. 23 is a flowchart of the steps utilized by the system of the present
invention for
implementing the "While Viewing" commercial avoidance feature;
FIG. 24 is a block diagram of the components of the commercial avoidance
systems of
the present invention;
FIG. 25 is a diagram of the commercial monitoring center as shown in FIG. 24;
FIG. 26 is a diagram of an alternate embodiment of the commercial monitoring
center
shown in FIG. 25.
FIG. 27 is a diagram of the components utilized by the system of the present
invention to
process remotely issued commands.
DETAILED DESCRIPTION OF THE INVENTION
A. Transmission Network.
FIG. 1 depicts a wide area television information transmission and utilization
system 5
constructed in accordance with the invention. With reference to FIG. 1, system
5 includes an
information transmission subsystem 6 which transmits television scheduling and
other
information as described below to a plurality of user locations 7. Each user
location 7 includes
a conventional television receiver, and may include a conventional video
cassette recorder
(VCR), and a user device that receives the television scheduling and other
information and uses
this information, along with inputs provided by a user, to control the
television receiver and
VCR, as also described below.
As shown in FIG. 1, the information transmission subsystem 6 includes a
central
information broadcasting computer 10, which receives television schedule
information,
television episode, news, sports, weather and other information (generally
identified as
"miscellaneous information"), as well as certain command and system
information used by the
system (generally identified as "system information") from a variety of
external information
sources 12, including third party vendors, other parts of the subsystem 7, and
internal databases.
Broadcasting computer 10 stores this scheduling, miscellaneous and system
information in its
own databases 14 and periodically transmits it electronically (in the manner
described below)
over wide area network ("WAN"~ 16 to a plurality of pager terminals 18. In a
preferred
embodiment, wide area network 16 is a conventional commercial frame relay
digital data
transmission network which transmits data using the conventional TCP/IP
communications
protocol.
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1 Referring now to Fig. 2, each pager terminal 18 includes a computer 20
connected to the
WAN 16. Computer 20 is connected to converter 22, which converts the
information received
from WAN 16, which is received in conventional digital form, into radio
frequency (RF) signals
suitable for radio transmission. Converter 22 is connected to a high-power RF
transmitter 24
S which broadcasts the information from pager terminal 18 in the form of
analog radio pager
signals in the 931 MHz frequency band, which is the frequency band designated
for pager use
by the Federal Communications Commission. In the preferred embodiment, over
one hundred
pager terminals are used to cover the continental United States. The
information sent to each
pager terminal, in particular the scheduling information, is customized to
reflect accurate data
(program listings, times, etc.) for the geographic region covered by that
terminal. The broadcast
computer 10 preferably transmits the scheduling, miscellaneous and system
information to the
pager terminals 18, and the pager terminals 18 preferably broadcasts the
information to the user
locations 7, during the night, when there is low usage of the pager frequency
band. The pager
terminals 18 broadcast the information using any of a number of well-known
paging transmission
protocols, including POCSAG or the Motorola FLEX protocol.
B. User Location 7
Referring again to FIG. 1, as noted above the information transmission
subsystem 6,
through the pager terminals 18, broadcasts the scheduling, miscellaneous and
system information
to user locations 7. Each user location 7 includes a user device, identified
herein as a set-top box
30, a conventional television receiver 32, and may also include a conventional
VCR (not shown).
The set-top box 30 receives the scheduling, miscellaneous and system
information, and uses the
scheduling and miscellaneous information, in particular, to generate
information displays which
it provides to the television receiver 32 at the user location 7. In addition,
by means of a user
control device 50 (see FIG. 3), such as a remote control device, the user may
provide user
information to control the set-top box 30 to, in turn, control the television
receiver 32, to, for
example, to change channels, display programs at their scheduled times, and
also to enable the
VCR to facilitate recording of certain programs. For example, the set-top box
30 will receive and
store user information relating to displaying certain programs which are
broadcast at certain
times, and, at the appropriate times will generate appropriate infrared
control signals which are
received by the television receiver's remote control infrared detector to
enable the television to
mm itself on (if it is not already on), switch to the appropriate channel and
display the program.
At the end of the program, the set-top box 30 may enable the television
receiver 32 to switch to
another program, or a user has enabled that to occur, to remain on at the same
channel, or to
switch itself off. In addition, the set-top box 30 will receive and store user
information relating
to recording of certain programs which are broadcast at certain times, and
will generate the
appropriate infrared control signals which are received by the VCR's remote
control infrared
detector to program the VCR to record. The set-top box 30 may also enable the
VCR to play the
recording over the television receiver 32 at a selected time.
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1 FIG. 3 depicts a functional block diagram of a set-top box 30 useful in a
user location 7.
With reference to FIG. 3, each set-top box 30~ includes an RF receiver 34
which is tuned to
receive scheduling, miscellaneous and system information in the 931 MHz band.
RF receiver 34,
which in one embodiment comprises a conventional receiver used in conventional
paging
devices, converts this scheduling, miscellaneous and system information from
analog to digital
form and supplies the scheduling and system information in digital form via
bus 38 to a central
processing unit ("CPU") 36 included in set-top box 30. In a preferred
embodiment, CPU 36 is
a standard 16-bit microprocessor which, in one embodiment, comprises a
microprocessor
selected from the Motorola MC 68000 microprocessor family. CPU 36 processes
the digital
scheduling and system information and stores it in a memory 38, which in one
embodiment
comprises a battery-backed random access memory implemented in conventional
random access
memory chips. In addition, the set-top box 30 includes an EEPROM 40 which
stores device
information such as a serial number, subscription controls and certain setup
information provided
during setup of the box 30 as described below. The set-top box 30 also
includes a read-only
memory ("ROM") 42 which contains the program for controlling CPU 36. In one
embodiment,
ROM 42 provides 8-bit words, and a latch and state machine 44 enables the ROM
42 to emulate
a 16-bit device in communications with CPU 36.
The user control device S0, which in one embodiment is a battery-powered
infrared
remote control device ('IR remote') produces a low-powered, wide-angle
infrared beam 52 which
is modulated in response to inputs provided by a user to supply user
information, in the form of
user commands, to the set-top box 30. Beam 52 is detected by an IR decoder 54
included in set-
top box 30 and the received infrared signal is converted into digital signals
which are processed
by CPU 36.
An RF switch 58 is provided to enable the set-top box 30 to generate RF
signals which
are displayed by the television receiver 32. The RF signals will provide a
video display by the
television receiver 32 of scheduling and miscellaneous information provided by
the information
transmission subsystem 6, thereby enabling the system 5 to display the
information to the user.
The RF switch is connected to receive signals from set-top box 30 by a cable
56 and from an
external device 64 (which may be the VCR, a video disc player, a cable decoder
or television
antenna), and to provide signals via a coaxial cable 66 to the. television 32.
If the set-top box 30
is not providing an RF signal to RF switch 58, then RF switch 58 will pass
signals provided by
the external device 64 to television 32. On the other hand, if the set-top box
30 is providing an
RF signal to the RF switch 58, then the RF switch 58 will block any signal
being provided from
external source 64 and will pass the signal provided by set-top box 30 to
television receiver 32.
When the set-top box 30 is providing RF signals for the television receiver 32
through RF switch
58, it also will generate appropriate infrared control signals which are
received by the television
receiver's remote control infrared detector to enable the television to switch
to an appropriate
channel to display the RF signals which it (the set-top box 30) generated.
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1 As noted above, the set-top box 30 can also control the television receiver
32 and the
VCR, as well as any other external devices 64, by means of an infrared control
signal. The
infrared control signal is provided by an infrared output terminal ("IR
output") 60. IR output 60
produces infrared signals at a range of frequencies, duty cycles and bit-cell
times, based on
commands from CPU 36, to. emulate most commercially available consumer remote
controls,
as described below.
In one embodiment, the system 5 operates as follows: Throughout the day and
night, the
information transmission subsystem 6 transmits, and the RF receiver 34 of set-
top box 30
receives updated scheduling, miscellaneous and system information and stores
it in the memory
38. While television 32 is on, the user may issue commands directly to set-top
box 30 using user
control device 50. Certain commands will cause set-top box 30 to, through the
RF switch, display
scheduling and miscellaneous information on television receiver 32. While
scheduling and
miscellaneous information is being displayed on television 32, signals and
programming from
external device 64 are blocked by RF switch 58. When scheduling and system
information is
being displayed on television 32, the set-top box 30 is said to be in "Display
Mode." Using user
control device 50, the user may select certain scheduling and system
information being displayed
on television 32. Based on the user's selections, set-top box 30, by means of
IR output 60, may
send channel tuning or program playback or recording commands to television 32
or external
device 64 or store such commands in the memory 38 and send them at a later
time. In an
alternate "TV mode," the user may view broadcast or recorded programming on
his television
using the user control device 50 to control the external device 64 supplying
such programming.
C. RF Receiver 34, Data Deserialization.
HG. 4 depicts a functional block diagram of an RF receiver 34 useful in the
set-top box
30. As noted above, the RF receiver 34 receives the scheduling, miscellaneous
and system
information broadcast by the information transmission subsystem 6. With
reference to Fig. 4, in
one embodiment the RF receiver 34 includes a tunable RF receiver 70 which is
tunable within
a range of approximately two MHz around 931 MI-Iz. This frequency range was
chosen because
it corresponds with the frequency used by national and local pager networks.
Tunable RF
receiver 70 is also connected to a received signal strength indicator ("RSSI")
80, which is
connected to CPU 36. RSSI 80 determines the relative strength of the signal
being received by
tunable RF receiver 70 and provides this data to CPU 36. This relative signal
strength data
enables CPU 36 to assist the user with the placement of set-top box 30 during
installation, to
enable the user to locate the set-top box 30 in a location at which it can
receive a signal from
information transmission subsystem 6 of a suitable signal strength, as
described below.
Tunable RF receiver 70 is also connected to a demodulator 72, which converts
the analog
signal received by tunable RF receiver 70 into either an unblocked two or four-
level analog
signal, depending on the paging protocol being used by the system. In one
embodiment, in which
the information transmission subsystem 6 may broadcast information in either
the POCSAG or
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1 the FLEX transmission protocol, the demodulator 72 initially attempts to
decode the information
on the assumption that the information transmission subsystem 6 had used the
POCSAG
protocol. If the demodulator 72 determines that it is unable to identify
suitable code words in the
broadcast information, it attempts to decode the information on the assumption
that the
information transmission subsystem 6 had used the FLEX protocol, by searching
the information
for possible good FLEX packets. When the demodulator 72 identifies the
appropriate protocol,
it generates an analog signal in response to the receives signal which it
provides to a data
deserialization module 74, which, in turn, converts the analog signal into a
digital signal and
provides this digital signal to CPU 36.
It will be appreciated that the data in the information broadcasts received by
the set-top
box are generally in serial form, and the data deserialization module 74
deserializes the data to
form word parallel data. As shown in Fig. 5a, data deserialization module 74
includes an analog-
to-digital converter ("A/D converter") 78, which receives analog signals from
demodulator 72
and converts them to digital signals at conventional TTL (transistor-
transistor logic) voltage
levels. A/D converter 78 then supplies these digital signals to comparator 82.
Comparator 82
compares each digital signal to one or more threshold values and produces one
or more digital
output signals based on the results of such comparison. In the preferred
embodiment shown in
Fig. 5a, comparator 82 compares the input signal with three threshold values
(designated
Thresholds 1, 2 and 3) to generate two output voltages (designated MSB 86 and
LSB 88) in
accordance with the following table:
Input Compared Output Is
To Threshold
1 2 3 MSB LSB
Greater Greater Greater 1 0
Greater Greater Less 1 1
Greater Less Less 0 1
Less Less Less 0 0
The threshold voltages of comparator 82 are set by CPU 36 during set-up by
measuring
input values while the received signal strength is high and gathering
statistics on the digital
values that are generated. The threshold voltages may be adjusted by CPU 36
based on changes
in the statistics due to temperature or other environmental change which
allows the module 74
to compensate for voltage drift of the demodulator 72 due to such changes. A
temperature
measurement device 84 is connected to CPU 36.
In an alternate embodiment of the data deserialization device 74, which is
shown in Fig.
5b, comparator 82 compares the signal with only one threshold value to
generate a one-bit output
signal. This embodiment may be useful primarily in connection with, for
example, the Motorola
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1 FLEX protocol. The use of one threshold instead of three provides a wider
voltage gap between
different signal levels and thus provides greater noise immunity than a three-
threshold
embodiment. However, less information is conveyed in the same time period by a
signal having
two rather than four possible values.
Refernng again to the embodiment depicted in Fig. 5a, to eliminate certain
noise-related
errors, comparator 82 compares its input signal with the threshold voltages)
multiple times
during a "bit cell period." A "bit cell period" is a time window in which one
unit of scheduling
and system information (comprising, depending on the number of voltage
thresholds used by
comparator 82, one or two bits of information) is broadcast by the information
transmission
subsystem 6. In one embodiment, comparator 82 makes eight voltage comparisons
during each
bit cell period. Because the analog signals received by RF receiver 34 contain
no embedded
clocking information, CPU 36 must also ensure that the phase of the input
signals corresponds
to the bit cell period of comparator 82. The time interval between comparisons
is controlled by
clocking signals from a modulo-8 counter 96 which is connected to comparator
82 and CPU 36.
For example, in FIG. 7a, an input signal is shown in which the comparisons are
in phase with the
input signal, that is, the comparator performs all of the comparisons while
the input signal
represents a single data bit. In that case, the comparator 82 is in phase with
the input signal. On
the other hand, in Fig. To, an input signal is shown in which the data bit
transitions during the
bit cell period; that is, the first three comparisons (0, 1 and 2) are for
data bit having a low value,
and the last five comparisons (3 through 7) are for a data bit having a high
value. The system 5
attempts to prevent the situation illustrated by Fig. 7b from occurnng during
information
broadcast by including in the broadcast signals, at the beginning and end of
each of a series of
data segments, a pre-defined sequence of data bits, such as signals
representing a series of binary
"zeroes" followed by signals representing a series of binary "ones" which the
CPU 36 may use
to ensure that its bit cell period is in phase with the transmitted data. If
CPU 36 detects a
transition in the middle of a bit cell period, as shown in Fig. 7b, it will
increment the modulo-8
counter 96, effectively shifting the sample window of Fig. 7b to the left by
one increment. This
process is repeated until the bit cell period roughly corresponds to the
beginning and end of the
information segments that are being received.
During normal operation, after the CPU 36 has brought the comparator 82 into
phase with
the bit cell period of the received signal, radio transmission noise could
interfere with the
accurate interpretation of the scheduling, miscellaneous and system
information. As shown in
Fig. 8, which illustrates noise in a received signal, six of the eight
comparisons made by
comparator 82 during the shown bit cell period result in an output (the MSB-
LSB combination)
of "00", while two comparisons result in an output of "O1." To determine which
of these results
should be passed to the next stage of data interpretation, bit sampling
modules 90 and 92 are
used. Bit sampling module 90 receives MSB 86 as an input, while bit sampling
module 92
receives LSB 88 as an input.
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1 The bit sampling modules 90 and 92 determine values for the most and least
significant
bits, respectively, based on the number of comparisons by the comparator 82
during a bit cell
period giving rise to each bit value. That is, if comparisons generated by the
comparator 82
during a bit cell period identify zero through three comparisons for the most
significant bit
S indicating the value "one," the bit sampling module 90 will identify the
value "zero" for the most
significant bit. On the other hand, if four through seven comparisons for the
most significant bit
indicate the value "one," the bit sampling module 90 will identify the value
"one" for the most
significant bit. The bit sampling module 92 operates similarly in connection
with the least
significant bit.
More particularly, the logical operation of bit sampling module 90 is
illustrated in Fig. 6.
Bit sampling module 92 operates in an analogous manner and will not be
described in detail. The
most significant bit signal from comparator 82 is coupled over line 86 to 3-
bit counter 100. Each
time the most significant bit signal identifies a "one," counter 100 is
incremented by one. A bit
counter 108 is incremented each time the comparator 82 provides a new value
identification, and
so when the value of counter 108 reaches 8 at the end of each bit cell period
it generates a reset
signal to reset the counter 100. At the end of each bit cell period, prior to
the reset of counter
100, a gate array 102 evaluates the status of counter 100. If the value of
counter 100 is 000, 001,
010 or Ol 1 (0, 1, 2 or 3), then the value of the most significant bit, as
coupled by gate array 102
over output 104, will be "zero." On the other hand, if the value of counter
100 is 100, 101,110
or 111 (4, S, 6 or 7), the value of the most significant bit will be "one."
In addition, the bit sampling module 90 generates a value identifying the
"quality" of the
bit sample, in relation to how close the final value of counter 100
corresponds to the "ideal" or
"no noise" value of 0 or 7. In one embodiment, gate array 102 accomplishes
this by comparing
the first two bits of counter 100. If the two bits are different (representing
a "noisy" value of 2,
3, 4 or 5), then the gate array 102 sets an "alert" flag 106, which flag may
be accessed by other
portions of the system. If the two bits are identical (representing a "clean"
value of 0, 1, 6 or 7),
then the "alert" flag 106 is reset to 0. Alert flag 106 is the output of a D
flip flop 109, the data
input of which is connected to the output of gate array 102, and the clear
input of which is
connected to counter 108.
Thus, in the example shown in Fig. 8, bit sampling module 90 will count 8
zeros and no
ones for the most significant bit for the bit cell period, resulting in a zero
output for the most
significant bit; and bit sampling module 92 will count 6 zeros and 2 ones,
resulting in a zero
output for the least significant bit. Because counter 100 of each bit sampling
module 90 was not
2, 3, 4 or 5, the alert flag 106 was not set for either bit, indicating a
relatively noise free bit.
Referring again to Fig. 5a, at the end of each bit cell period, the outputs of
bit sampling
modules 90 and 92 are each shifted into a respective 16-bit shift register 110
and 112. After 16
such shifts, a modulo-16 counter 114 resets and causes the contents of shift
registers 110, 112
to be shifted into respective 16-bit hold registers 120 and 122. This shift
causes an interrupt
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1 signal to be sent to CPU 36, which enables the CPU 36 to read the data in
the hold registers 120
and 122. In an alternative embodiment of the invention, modulo 16 counter 114
may be
incremented by CPU 36 to cause the phase of the sample period to correspond
with the phase of
the input data as discussed above with respect to FIGs. 7a and 7b.
D. Video Generation
The set-top box 30 stores video image data used to define the video image that
is
transmitted to television receiver 32 in its memory 38. The video image data
is retrieved from
the memory 38 in a conventional manner for use in generating the RF signal
coupled to the RF
switch 58.
E. Data Processing.
System Control Flow. As illustrated by Fig. 9, the CPU 36 runs under the
control of a
commercially available real-time operating kernel (in one embodiment, the
Nucleus Plus kernel
from Accelerated Technologies) which provides task scheduling and
communications facilities
for the system. Information received from the RF input 34 as described above
is sent in software
queues to waiting destination processes, while IR commands from the user
control device 50 are
processed by an interrupt-based driver and passed to a global event queue to
be received by the
currently activated application. In addition, some processes, such as those
controlling VCR
recording, are suspended until scheduled events, such as times to start or
stop a VCR, occur.
Data De-Interleave. Data transmitted to the system in the Motorola FLEX paging
format
is 8-way interleaved for additional noise immunity as follows:
Reg D D6 DS D4 D3 D2 D DO
1 1
0 AO BO CO DO EO FO GO HO
1 A1 BI Cl Dl El F1 GI H1
2 A2 B2 C2 D2 E2 F2 G2 H2
3 A3 B3 C3 D3 E3 F3 G3 H3
4 A4 B4 C4 D4 E4 F4 G4 H4
5 AS BS CS DS ES FS GS HS
6 A6 B6 C6 D6 E6 F6 G6 H6
7 A7 B7 C7 D7 E7 F7 G7 H7
Data is received down the columns of the above table beginning with bit A0,
followed by
B0, C0, ..., H0, Al, ..., H31. To de-interleave the data, the CPU 73 has a set
of eight registers
which "rotate" their bits ninety degrees. That is, data is loaded into these
registers as follows:
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1 Reg data? data6 data5 data4 data3 data2 datal data0
0 AO A1 A2 A3 A4 AS A6 A7
1 BO B1 B2 B3 B4 BS B6 B7
2 CO C1 C2 C3 C4 CS C6 C7
3 DO D1 D2 D3 D4 DS D6 D7
4 EO E1 E2 E3 E4 ES E6 E7
FO Fl F2 F3 F4 FS F6 F7
6 GO G1 G2 G3 G4 GS G6 G7
7 HO Hl H2 H3 H4 HS H6 H7
Upon reading by the CPU 36, the data is rotated so that it appears as follows:
Word Bit
A 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 .. 31
B 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 .. 31
C 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 .. 31
2o D 0 I 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 .. 31
E 0 I 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 .. 31
F 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 .. 31
G 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 .. 31
H 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 .. 31
Because the CPU 36 addresses the registers and memory 38 on a byte-by-byte
basis, only
one byte at a time needs to be rotated using the above method, although a full
256 bits
(corresponding to eight 32-bit words) must be read before all eight words can
be assembled.
Database Storage. As illustrated by Fig. 10, there are three classes of
scheduling,
miscellaneous and system information received by the CPU 36, namely User
Information
150, Command Information 152 and System Information 154. As illustrated by
Fig. 1 1, the
scheduling, miscellaneous and system information received by the set-top box
30 comprises a
series of individual segments, with the each segment being associated with
classification bits 174
which identify the segment's class.
"User information" includes scheduling and miscellaneous information,
including program
title information, program schedule information, and episode description
information, as well
as textual information such as news, weather, sports and information related
to other subjects,
each of which is associated with one of a plurality of sub-classes. Upon
recognition by the CPU
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1 36, User information is sent by the CPU 36 to one of a plurality of database
writers 162 which
corresponds to the sub-class. The database writer 162 then writes the
scheduling and system
information to memory 38 in an appropriate database 164, from which it may be
recalled and
displayed at a later time.
"Command Information" includes information which causes the IR output 60 to
issue
specific commands to external devices, such as the television receiver 32 or a
VCR, such as
commands to avoid real-time commercial broadcasts as discussed below. The CPU
36 receives
Control Commands in a genetic format, and then retrieves corresponding IR
control codes and
sequences corresponding to the user's external device from an IR Library 166,
which holds the
specifications for the user's particular device configuration. Control
Commands may originate
either from the user control device SO or from broadcasts received by the RF
receiver 34.
"System Information" includes command information which automatically alters
the
CPU's programming to initiate software bug fixes and add new services or
databases without the
interaction of the user. System Information will typically originate at the
information
transmission subsystem 6.
Database Output. The arrangement by which the set-top box 30 retrieves
information
from the databases will be illustrated by the example of Fig. 12, in which a
user, through the user
control device 50, has elected to view news information. When a user chooses
"news" from a
screen display on which news is an option, a program called the news display
application 182
is called by the operating kernel 180. The news display application 182
downloads data from the
news database 184 and, based on the user's commands, downloads this data to a
memory display
list 186. The memory display list 186 sends the data to video hardware 188,
which generates an
RF output to transmit the data in video form through RF switch 58 for display
on the television
32.
Automatic Display ordering. The set-top box 30 can enable the program schedule
information to be displayed by the television receiver 32 with an alphanumeric
ordering that is
based on channel number or name, or with an based on the user's viewing
habits. With reference
to FIG. 13, to allow the channel ordering to be based on the user's viewing
habits, the set-top box
maintains a running record of the amount of free the user views the various
channels over a
30 selected period of time, and orders the channels based on a viewing time
rating that is a function
of actual viewing time over a can ent viewing period, for example, the
previous day or week, and
further based a decaying function of viewing time for viewing periods before
the current viewing
period. The set-top box 30 also can enable the ordering of other types of
information, such as
news information, that it enables the television receiver 32 displays based on
the user's viewing
habits. In that operation, each item of news information is mated with one of
a number of
categories, and the set-top box 30 keeps track of the classes of news
information viewed by the
user. In addition, the set-top box 30 will order the items of news information
based on the ages
of the items and a priority value that is assigned by system 5.
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1 Automatic Memory Recovery. Because the information in the set-top box's
databases
is continuously updated, the set-top box 30 includes an arrangement for
deleting old items and
otherwise recovering database storage space. Any of a number of conventional
memory recovery
methodologies may be used to select existing memory space to be over-written
by new data. As
illustrated by the flow chart of Fig. 14, when an application or database
management tool
requires memory to store scheduling and system information, the kernel
initiates a "memory
request" in step 192. If sufficient free memory is not available, each
application is then called
with an "automatic memory recovery" request to execute "clear routine" thereby
freeing low
priority memory items. In one particular embodiment, memory recovery is
accomplished in three
ways:
(1) Certain database items are tagged with a specific "data type identifier,"
(or "slot
identifier") which allows future items having the same data type identifier to
simply replace
them, recovering the memory occupied. by the original. This may be used, for
example, to allow
a particular news story to be updated with new information by replacing the
outdated
information.
(2) Most database items include aging information, such as information as to
when
they were added to thedatabase, so that they may be deleted a certain period
of time after they
have been added to the database. For example, portions of memory in which
miscellaneous
information, such as news, weather, and sports information, is stored may be
used for new
information after a selected period of time, and portions in which television
program schedule
information is stored may be used for new information after the program
transmission time has
passed.
(3) Portions of memory in which database items which have low ratings under
the
display ordering system may be used for new information a short time after
they were loaded into
memory. fla user rarely or never accesses certain types of miscellaneous
information, portions
of memory in which those types of information are store may be re-used before
it has aged
greatly. If a user rarely or never watches a particular channel, or if the
user seldom watches
television during a particular time period (such as early morning, midday,
etc.) the schedule
application may delete the "scheduling information" relevant to that channel
or time period when
additional memory is needed. In an alternative embodiment, an item's display
ordering rating is
considered in combination with its age to determine whether the portions of
memory in which
that item is stored should be re-used.
F. User Interface.
I. IR Remote.
Operation. According to commands issued by the CPU 36, the IR decoder will
interpret
infrared control signals supplied by the user control device 50 in one of two
modes: "raw" or
"demodulated." The "raw" mode is used during the system set-up as described
above. In
"demodulated" mode, the IR decoder will generate a continuous digital "1"
output to the CPU
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1 when certain infrared control signals are detected and will otherwise
generate a digital "0"
output. Demodulated mode is used to enable the user to select a highlighted
tile from various
display screens using the user control device 50 and to provide the set-top
box 30 with other
commands.
S In "raw" mode, the IR detector generates a time stamp for each infrared
input it receives,
and records data such as the IR carder frequency, duty cycle and encoding
method of such input.
In one embodiment, the user control device 50 a carrier frequency of
approximately 80
Khz, which will insulate the IR detector from stray signals generated by other
consumer
electronic devices, most of which transmit at carder frequencies in the 40-S 0
KHz range, and will
also ensure that the user control device 50 will not interfere with the
operation of other consumer
devices having infrared inputs, particularly the television and external
devices which may be part
of the video system.
Layout. As shown in Fig. 15, the IR remote of the preferred embodiment
contains 8 keys
designated as follows:
GUIDE key 250
TV key 251
UP key 252
DOWN key 253 ("Directional Pad" buttons)
LEFT key 254
RIGHT key 255
LEFT SOFTKEY 256
RIGHT SOFTKEY 257
Universal Remote Usage. When the system is in TV mode, the Directional Pad
buttons
and the softkeys function to control the television and external devices. In
that mode, the up and
down keys 252 and 253 are used to increment and decrement the channels,
respectively, the right
and left keys 255 and 254 are used to increase and decrease volume, the left
softkey 256 is used
to turn power on and off, and the right softkey 257 is used to control device
muting.
II. Screen Displays.
1. Basic Screen Display Features. The set-top box can present a variety of
screen
displays on the television. As descried above, the screen displays are
provided by the set-top box
30 by means of an RF signal coupled through the RF switch 58, and when the set-
top box
provides such a screen display, it enables the television receiver 32 to
switch to the selected
channel (such as channel 3 or 4) for screen display by providing an
appropriate infrared signal
to the television receiver's infrared remote control input. As illustrated in
Fig. 16, every screen
display has a common Banner Area 240 which describes the functions of the
softkeys for that
screen and lists the title of the screen display. Most screen displays also
include a number of
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1 boxes enclosing text, each of which is referred to as a "tile" 244, and
which collectively form a
"grid" 242.
When the user has selected a tile, or moved the cursor onto a tile using the
directional
keys of the IR remote, the color of the tile will change, and it is said to be
"highlighted." In
screen displays that include program titles, different types of programming
can be represented
by tiles of differing colors.
If the highlighted tile is near an edge of the screen display, the screen
display will
automatically "scroll" to bring the highlighted tile near the center of the
screen display. Certain
screen displays do not allow the highlighted tile to be at the edge of the
display screen unless no
information is contained off screen beyond the edge of the display screen.
All screen displays also have an information area 246 which displays further
information
about the selected tile, such as episode information about a selected program
or additional
information about a news headline.
Navigation in Screen Displays. The buttons of the user control device 50
enable the user
to access all screen displays and features of the system that may be
controlled by users. Pressing
the directional buttons 252-255 of the IR remote 50 moves the cursor and
highlighted tile up,
down, left and right on the grid. Pressing the GUIDE key 250 will select a
highlighted tile and
switch the system to the next display screen (bringing up the Navigation
Screen if the user is
currently watching television programming). Pressing the TV key 250' will
return to television
progrunming from the screen displays, either tuning to a new station if the
Program Grid screen
display was active immediately prior to pressing TV and the program
highlighted on the Program
Grid is available, or tuning. back to the original station being watched if
not. In screen displays
that display a grid of television program scheduling information (i.e. Program
Grid, Programs
by Title, TV Movies and Sports Ticker), LEFT SOFTKEY 256 will cause the
highlighted
program to be recorded. A summary of the functions available in each display
screen is
illustrated in Table I below:
Current GUIDE TV Key LEFT key RIGHT Up/Down Left/Right
Display key fn function function key fii key fii Key Fn
TelevisionBrings Brings MUTE TV Power Channel Volume
up up
viewing NavigationPrevious televisionOn/Off Up/Down Up-down
Screen Screen
NavigationBring up Return various various select choose
to
Screen Selected TV screen screen
tile
Screen Viewing option
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1 Program Bring up Tune to Record Advance grid selectgrid select
Grid TV Movie selected selected display up-down left/right
one
Screen program program day
TV Movie Bring Up Tune to RECORD unused grid selectgrid select
Screen Sports selected selected up/down left/right
Screen program program (choose
day)
Sports Bring up Return [record unused grid selectgrid select
to
Screen News TV selected up/down left/right
Screen Viewing game]
News Return Return [previous[next pagegrid selectText Page
to to
Screen TV TV page of of text] up/down Select
Viewing Viewing text] (Headline)ForeBack
Navigation Screen. Refernng to Fig. 17, the Navigation Screen 258 is the first
screen
displayed after the user presses the GUIDE button 250 of the user control
device 50. The
Navigation Screen lists the major screens that are available in one
embodiment, namely, TV
program Listings, TV Movies, Sports and News. In addition, certain non-screen
features of the
system have tiles on the Navigation Screen, including the commercial avoidance
feature, as will
be described below. The Navigation Screen may also include other information,
such as personal
messages, reminders or paid advertising.
Program Grid. In the Program Grid 260, shown in Fig. 18, tiles contain
television
program titles 262, arranged vertically by broadcaster, such as the station or
network, and
horizontally by time. The information area 263 displays further episode
information about the
highlighted tile. The RIGHT SOFTKEY 257 advances the screen display one day in
time.
Sports Ticker. As shown in FIG. 19, the Sports Ticker display shows
information relating
to different sporting events and their ongoing scores. When the highlighted
tile represents a
specific sports event, further information relevant to that event is shown in
the Information Area.,
If events are televised, an icon, which in one embodiment is a small
representation of a television
receiver, is displayed in the tile. For these televised events, a user can
cause the set-top box 30
to enable the television receiver 32 to switch to that program by highlighting
and selecting the
tile associated with the event in the same manner that he or she can enable
the set-top box 30 to
select programming through the Program by Title screen.
News. As shown in Fig. 20 the News display uses a scrolling list of tiles to
show brief
headlines of news stories. The user may use the user control device 50 to
select a tile, and the
Information Area shows the full text of the news story associated with the
selected tile.
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1 Other Screens. Other embodiments of the invention may include screen
displays with
features such as horoscopes, crossword puzzles.
I. Other Features
1. Recording Programs.
Selection of Programs for Recording. In the display screens including program
titles, the
user may select a program for recording by highlighting that program's tile
and pressing the
LEFT SOFTKEY 256. When a program is scheduled to be recorded, the background
color of its
tile is changed to a selected alternate color, which in one embodiment is red.
Programs can be
scheduled to be recorded at selected intervals, including "once" or "always."
When a program
is scheduled to be recorded once, the CPU will cause the VCR to record the
program at the date
and time selected. The user may select recording once by pressing the LEFT
SOFTKEY 256
once on a tile. When a program is scheduled to be recorded regularly, the CPU
will cause the
VCR to record the program each time it occurs in the time slot originally
selected by the user.
The user may select recording regularly by pressing the LEFT SOFTKEY 256 twice
when a tile
is highlighted.
As shown in the flow chart of Fig. 21, the automatic recording process varies
depending
on the particular system configuration. In step 270, the recording process is
initiated by pressing
the LEFT SOFTKEY 270, and if it is determined in step 271 that the system does
not include a
cable decoder, as indicated during the set-up procedure described above, at
the time of broadcast
of a program scheduled to be recorded, the set-top box's IR output 60 will
send a channel change
in step 272 and a "Record" command to the VCR in step 273, and at the end of
the scheduled
program, a "Stop" command will be sent to the VCR. If a cable decoder is used
in the system,
a channel change command will be sent to the cable decoder a selected amount
of time in
advance of the scheduled recording time in step 274 and a "Record" command
will be sent to the
VCR by the IR Output 60 in step 273 at the time of scheduled broadcast; a
"Stop" command will
be sent to the VCR at the scheduled end of the broadcast.
2. Commercial Avoidance.
In one embodiment, the set-top box 30 can enables users in certain areas of
the United
States to avoid broadcast advertising during the viewing or recording of
television programs on
certain channels. This feature is selected by the user through a tile on the
Navigation Screen.
While this tile is seized, moving the directional control up or down chooses
between the
following options: "Off', "While Viewing", "While Recording", and "While
Viewing and
Recording". The implementation of each of these options will now be discussed.
"While Recording": Referring to Fig. 22, if a program is being recorded when a
commercial break occurs as described below, the IR output 60 will send a
"pause enable" signal
to the video recorder in step 304 and will not send a "pause disable" signal
to the video recorder
in step 308 until the end of the commercial break is detected in step 306. As
a result, the video
recorder will not record commercials. This feature saves videotape during the
unattended taping
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1 of programming.
"While Viewing": Referring to FIG. 23, If a user, who has selected this option
in step
320, is viewing a channel ("Channel A") when a commercial break occurs as
detected in step
322, the IR output 60 of the set-top box 10 will issue a "mute enable" command
to television 32
in step 324. The television then substantially diminishes the volume of the
television for the
duration of the commercial break in step 326, and will not issue a "mute
disable" command to
the television 32 in step 330, to restore the volume in step 332, until the
commercial break is
over in step 328. If the system detects in step 334 that the user has changed
the channel' (to
"Channel B") using the user control device 50 after the "mute enable" command
is issued, the
IR output 60 will automatically issue a "mute disable" command in step 336,
restoring sound for
viewing of Channel B in step 338. In addition, when the end of the commercial
break on Channel
A is detected in step 340, the IR output 60 will automatically issue a command
in step 342 to the
television or cable decoder to tone back to Channel A in step 344. Then, in
step 346, Channel
B will be stored in a memory means as an "alternate channel" to be switched to
during
commercial breaks on Channel A. Upon the occurrence of the next commercial
break on Channel
A, the system will automatically tune the television to Channel B for the
duration of the
commercial break. Channel B may also be a display screen (such as Sports
Ticker or News).
The system 5 accomplishes "commercial avoidance" as follows. As shown in FIG.
24,
in one embodiment which may be used in areas in which television programming
is transmitted
to local television a~liates and rebroadcast without delay (typically the
Eastern and Pacific U.S.
time zones), commercial monitoring centers 380 monitor television programming
on those
channels and determine when a commercial break begins and ends. At the
beginning and end of
each commercial break, the commercial monitoring center 380 transmits to the
central
broadcasting computer 10 a message indicating the channel on which a
commercial break has
begun. The central broadcasting computer 10 then transmits, as system
information, Control
Information over the WAN 16 for transmission by RF transmitters 386
(corresponding to paging
terminals 18 in FIG. 1) in those areas in which the commercial break has
occurred. The Control
Information will be received by individual set-top boxes 30 and decoded and
interpreted by their
CPUs to be commercial avoidance information.
As shown in Fig. 25, in one embodiment the commercial monitoring center 380
includes
at least one human observer monitoring a television 386 tuned to the channel
being monitored.
At the beginning and end of a commercial break on the channel being monitored
by observer
384, observer 384 will depress a button 387 indicating to a computer 388 the
beginning and end
ofthe commercial break on such channel. The computer 388 will then transmit a
message to the
central broadcasting computer 10, as described above. In an alternate
embodiment shown in Fig.
26, individual observer error is minimized by causing multiple observers to
view each channel
and depress individual buttons at the beginning and end of a commercial break.
Logic module
390 of the computer 388 then logically combines the signals generated by the
buttons of the
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1 observers watching the same channels and sends a commercial break indication
to the central
broadcast computer when it receives indications from more than a predetermined
number of
observers (e.g. three) identifying the beginning and end of a commercial break
on the channel.
The commercial avoidance feature can also be provided in areas in which the
transmission of programming is delayed from an original transmission, without
requiring
providing observers for those areas as described above. In that operation, the
commercial
monitoring center 380 not only enables transmission of Command Information
identifying the
beginning and end of a commercial break in original transmission areas, that
is, in areas in which
program transmission is not delayed, it also enables transmission of Command
Information in
delayed transmission areas which identifies the times at which commercial
breaks begin and end,
which the set-top boxes 30 in those areas will store in their respective
memories 38. If a user uses
his or her set-top box 30 to control display or recording of a program for
which commercial
avoidance information has been provided, the set-top box 30 can use the
commercial break begin
and end times in the memory to control volume in connection with display of a
program by the
television receiver 32, as well as to control pause of a VCR in connection
with recording of a
program by a VCR.
3. Remote Operation.
As illustrated by Fig. 27, the system includes a central office 430 having a
plurality of
telephone connections 432, human operators 434 and terminals or stand-alone
personal
computers 436 networked to the central information broadcasting computer 10.
In the event that
a user 350 desires to issue commands to his set-top box while remote from the
box, for example,
if he forgot to program his VCR to record a program, he may telephone the
central office 430,
identify himself and provide a security code to the operator 434. If the
operator verifies the user's
identity (in a preferred embodiment, using a commercially available database
including user
name, security codes and set-top box serial numbers), the user may tell the
operator what
command he would like to remotely issue to his set-top box 30. The operator
will then access
the central information broadcasting computer 10 through his terminal or
personal computer 436,
and instruct the central information broadcasting computer 10 to transmit an
"individualized
command" through the WAN 16 to the RF transmitter 18 servicing the user's
area. An
"individualized command" is a control command containing the serial number of
the user's set-
top box 30, and which will be disregarded by all set- top boxes other than the
set-top box 30
having that serial number. Upon receipt and recognition of the individualized
command by the
user's set-top box 30, the user's set-top box 30 will execute the command.
The foregoing description has been limited to a specific embodiment of this
invention.
It will be apparent, however, that various variations and modifications may be
made to the
invention, with the attainment of some or all of the advantages of the
invention. It is the object
of the appended claims to cover these and such other variations and
modifications as come
within the true spirit and scope of the invention.
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