Note: Descriptions are shown in the official language in which they were submitted.
. CVO 94117632 PCT/US94100747
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T.V. VIEWING AND RECORDING SYSTEM
Field of the Invention
This invention relates generally to video
recorders and more particularly to a video recorder
operative to electronically interconnect and remotely
control the operation of an associated cable tuner/
descrambler and television receiver in accordance with user
view/record requests from the operator.
Background of the Invention
Video recorders, or VCRs, are commonly used in
conjunction with television receivers to facilitate the
recording of broadcast programming and the playback of pre
recorded cassettes. When the broadcasts are received over
a cable system, scrambled channels may be present, which
require descrambling before viewing or recording. A cable
tuner/descrambler or "cable box," including a remotely
controllable multi-signal tuner, is commonly employed to
descramble such signals.
To facilitate a particular recording or viewing
scenario, the necessary interconnections between the cable
box, VCR and TV set may be quite complex, particularly if
it is desired to watch one channel while viewing another.
Additional complexity arises from the fact that the VCR may
be equipped with a capability which allows automatic,
unattended recording of a program to be broadcast at a
future time. While the programming system may control the
VCR tuner in order to receive the desired program at the
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correct time, the cable-box and TV tuners must also be
properly adjusted, at the system level, in order to
accommodate the recording/viewing option.
Further complexity results from the VCR, cable
box and TV being typically equipped with separate infrared
remote-control transmitters. Although "universal remotes"
have been devised which can emulate multiple transmitters,
the process of training such devices presents its own
challenges to the consumer.
Long U.S. Patent 4,630,133 discloses a video
cassette recorder which is adapted to be connected to a
multi-channel cable, to a T.V. receiver into both the input
and output of the cable box. The V.C.R. incorporates
multi-position switches which allow the operator to
configure the intraconnection between the units in an
optimum manner to achieve a desired viewing or recording
function. The operator must manually adjust the switches
and independently configure the associated cable box and
T.V. receiver to implement an optimum configuration for
viewing and/or recording.
My U.S. Patent 5,123,046, discloses a system in
which a V.C.R. incorporates an infrared transmitter which
allows it to exercise control over the energization and
tuning of an associated and remotely controllable cable
box.
While both of these innovations facilitate the
operation of a television viewing system incorporating a
video recorder, cable tuner and T.V. receiver, the problem
of configuring the units in an optimum way and controlling
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their operation still requires a degree of expertise which
exceeds the abilities of the average television viewer.
Summary of the Invention
The present invention is directed toward a system
which would allow full transfer and sharing of video or RF-
modulated T.V. signals among the components of the
television viewing system in much the same way that a
computer bus allows data to be transferred between
peripherals and would make the realization of an optimum
configuration and the adjustment of the system components
to operate in consort with one another an automatic
function of the system. A preferred embodiment to the
invention constitutes a video recorder having connections
for receiving a multi-channel program signal source such as
cable television, to provide output to an associated
television and connections to both the input and output of
an associated cable box. The video recorder includes
electronically controlled switches which are capable of
interconnecting the tuner, record/playback means, signal
source, cable box and T.V. in an optimum configuration
based on user control inputs. The video recorder includes
an infrared transmitter capable of transmitting control
codes to both the cable box and the T.V. receiver to adjust
their parameters in such a way as to achieve the optimum
viewing/recording configuration.
An electronic controller within the VCR receives
command signals from an operator pertaining to desired
television viewing and recording options. In accordance
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with these commands, the controller automatically causes
the transmitter to send control signals to the cable box
and to the TV, and configures the switches to ensure that
all system components and tuners meet the desired viewing/
recording scenario.
Other advantages of the invention will be made
apparent by the following detailed description of the
preferred embodiment to the invention. The description
makes reference to the accompanying drawings in which:
Brief Description of the Drawincts
FIGURE 1 is a schematic diagram of a preferred
embodiment of the present invention including connections
to a source of cable television, a cable box and a TV;
FIGURE 2 is a simplified, schematic diagram of an
alternative embodiment of the present invention wherein
video signals are switched in lieu of RF signals;
FIGURE 3 is a chart of recording and viewing
options available as a function of the electrically
controlled switching in the VCR of the present invention;
FIGURE 4 is a flow diagram illustrating the
manner in which the system of the present invention
interrogates inputs to determine available channels,
including which channels are capable of being descrambled
by the cable box;
FIGURE 5 is a table illustrating how attributes
of each channel may be organized in accordance with the
present invention;
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FIGURE 6 is an illustration of the interaction
among system components upon receipt of a typical command
from a remote-control transmitter dedicated to the VCR of
the present invention; and
FIGURE 7 is an illustration of the interaction
among system components upon receipt of a typical command
from a remote-control transmitter dedicated to a system
resource other than the VCR, such as the television
receiver.
Detailed Description of the Preferred Embodiment '
Referring to Figure l, a video recorder (VCR) 22
formed in accordance with a preferred embodiment of the
present invention is shown in block-diagram form along with
a typical cable tuner/descrambler or "cable box" 24 and a
television receiver (TV) 26. All units are preferably
remotely controllable via infrared signals. A
multi-program signal source, such as that provided over a
television cable 30, is fed to an RF splitter 32 within the
VCR 22. The splitter has a first output at 33 which is
routed to the input of cable box 24 and a second output at
34 which is utilized within VCR 22.
The output of cable-box tuner 44 feeds a
descrambler 50, operative to decipher and demodulate
premium or "pay" channels, and the output of the
descrambler feeds a modulator 52 which modulates the video
signal derived by tuner 44 and reconstructed by descrambler
50, onto an unused VHF channel, channel 3. The modulated
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signal from the cable box is provided to the V.C.R. 22 on
cable 53.
Control codes for the cable box are received by
an infrared (IR) receiver 60. A hand-held remote-control
transmitter (not shown) is ordinarily used to transmit the
codes. The output of IR receiver 60 is interfaced to a
cable-box control unit 62, which is typically a programmed
microprocessor. In response to control codes received by
IR receiver 60, control unit 62 directs overall cable-box
operations, including causing tuner 44 to tune to the
channel specified by the received signal.
The RF output signal from VCR 22 is delivered to
TV 26 via a cable 98. The signal from the VCR is fed to
a tuner 70, though in a more sophisticated receiver the
signal may branch to additional tuners (not shown) to
facilitate operational features such as "picture-in-
picture," which enable the viewer to watch the program on
one channel while the program on another channel is shown
as a small video inset within the main picture.
Tuner 70 interfaces to a control unit 78,
preferably a programmed microprocessor, which in turn
interfaces to a display 80, usually in the form of a
cathode-ray-tube (CRT). TV control codes are received by
an infrared receiver 82, which feeds control signals to the
control unit 78. The audio portion of the tuned channel is
delivered to the viewer by a loud speaker 84, also
interfaced to controller 78.
The second output 34 of splitter 32, within the
V.C.R., is used as one input to a single throw, double
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pole, electronically controlled switch 48, the other input
being the RF output of the cable box on cable 53. The
output of switch 48 feeds a multi-channel tuner 46, which
demodulates the incoming RF signal to a video signal for
presentation to a video record/playback unit 92, typically
a cassette tape recorder/player.
The output of record/playback unit 92 is
delivered to an RF modulator 94, which modulates the video
signal onto channel 3 The RF modulated signal from block 94
forms one input to a three-input electronically controlled
switch 96, the other inputs of switch 96 being the second
output of splitter 32 and the output of the cable box tuner
on line 53.
The function of switch 48 is to choose the source
of program material for the video record/playback unit 92,
and the function of switch 96 is to select the source of
program material to be viewed on TV 26. It is important to
note that while Figure 1 illustrates the preferred
embodiment of the VCR's electronically controlled
switching, the inputs to both switch 48 and switch 96 may
be expanded to accommodate additional sources of program
material, such as a separate satellite receiver input.
The demodulated video output of tuner 46 is also
fed to a sync separator 56, which, in turn, feeds a signal
analyzer unit 58. The sync separator 56 is used in
conjunction with the analyzer 58 to determine if the cable
box is capable of descrambling a premium channel carried by
' cable 30. In the preferred embodiment, the sync separator
extracts a horizontal synchronization signal from the video
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output of tuner 46, and analysis unit 5s examines~~the
signal to see if it occurs an a cons~.steMt tj.me base or . ,
alternatively, if it is inverted. The functioning of sync
separator 5~ and analyzer.58 ~.n cQnjunGtion with tunex~ 45
will bo discussed further in refgrenoe to methods Ot~ the
present invention for co~np~,l,ihc~ ~annEl attributes.
A central contro],ler 100 within VCFt 22 receives
operator commands through a user ~.npe~t 102 , preferably
constituting a receiver for 1R co~ands generated by a
hand-held remote transmitter 3o0 (Figure 6). Controller
1oa interfaces 'to and/or cij.rects the operation of various
functional units within the vCR, including switches 4s and
9g, tuner 4s, recordrplaybaak unit 92, analyzer 58, audio
det.ectQr~$mp 119 and an infrared remote-control transmitter
10g, which is used to energize and. tune and otherwise
control the cable box 24 arid TV 2fi. The contrn~
associated with the cable box and TV are preferably stoxer~
in a pre--recorded read-on~.y memory (>;toM) 106, and channel
attributes are stored in a random-access memory (RAM) 107.
Both memories also interfaoe to controller loo.
Alternatively, the control, codes associated with the cab~.e
bole ahd' TV could be automatically ascertained by the VCR 22
Lksing~~>ther m~ttiod:~.
Figure 2 is a simplified schematic diagram of an
altcrhative embad~.ment of the switching arrangement present
invention wherein switches 48 and 96 are used to switch
video signals (drawn as thin lines}, instead of RF signals
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(drawn as thick lines). Some cable boxes, such as those
which provide the operator with control over the audio
' portion of the selected channel, demodulate the incoming RF
signal and provide demodulated audio and video outputs,
typically through a separate set of connectors 55 on the
cable-box housing, with cables being used to carry the
signals to an associated set of connectors 57 on the VCR.
Newer "component" TVs likewise provide the display as a
separate video monitor 90 which may be interfaced directly
to the audio/video outputs typically found on most VCRs,
including the VCR of the present invention.
As exemplified by Figure 2, the present invention
may be configured to switch RF signals on the video inputs
or any combination, depending upon the capabilities of the
associated modules.
Figure 3 lists the recording and viewing options
available as a function of the electrically controlled
switching in the VCR. Switch 48 may be set to position "1"
to record a signal from the cable box, including a
descrambled channel, or set to position "2" to record a
channel directly from the cable. With switch 96 at
position "A" the TV or monitor will receive a channel from
the cable box, including a descrambled channel . At " B" the
TV or monitor will receive the output of the tape unit, and
at "C" a channel directly from the cable.
Position "B" could also be used to monitor the
program currently being taped but it is anticipated that
this switch position will only be used to view a tape once
recorded, since positions "A" and "C" would provide a
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"cleaner" signal for viewing, especially if RF switches'are
used and the tape output needs to be modulated before
viewing. With RF switches it is also important that the
signal lines exhibit consistent loading on all positions.
Thus, additional switches 130 and 132, shown in Figure 2,
may alternatively be added to ensure that the RF lines are
never unloaded or "floating."
Using its infrared transmitter 108 and electrical
switches, the VCR of the present invention has the
capability to determine which channels which may be tuned
by the associated resources on hand, and configure those
resources in accordance with operator requests. Although
the preferred embodiment embodies the centralized control
for this channel determination and configuration within the
VCR, the system transmitter and switching could
alternatively be located within the cable box, TV or even
a hand-held remote unit.
When the VCR is first installed, or when a system
resource such as the cable is changed, the VCR
automatically scans its inputs to determine available
channels. In the preferred embodiment, the tuner 46 is
scanned through each channel and the output of sync
separator 56 is examined by controller 100 to detect the
presence of strong, regular sync pulses which, if present, .
indicate a tunable channel. An alternative technique for
determining whether a signal is present from a system
resource may be employed including the presence of an RF
signal or any attribute of the underlying video signal,
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including vertical or horizontal sync, color burst, or any
waveform specially encoded for identification purposes.
The flow diagram of Figure 4 indicates how the
present invention scans its inputs to identify tunable
channels. By virtue of a program stored in controller 100
the system preferably first begins with the incoming cable
by setting switch 48 to the "2" position, at step 150.
Controller 100 then analyzes the input for a video signal
using sync separator 56 and analyzer 58. If a channel is
present it preferably further examines the signal to
determine if it is scrambled, in which case it temporarily
stores that channel to later determine if the cable box is
capable of descrambling it, then increments the VCR tuner.
In the preferred embodiment, the controller decides if the
signal is scrambled by determining if the horizontal sync
is irregular or inverted, although alternative analysis
techniques may be used.
If the channel is not scrambled, it is stored as
tunable at block 152, and the VCR tuner is incremented. If
the channel is scrambled, it may be temporarily stored at
step 156 to later determine if it can be unscrambled. If
no signal is detected, that channel is stored as untunable
and "skipped" block 154. The VCR tuner 46 is incremented
through all of its settings at which point the system
determines which type of cable box is attached to the VCR
and what additional channels are available through
descrambling.
Using the control codes associated with the cable
box stored in RAM 107, the system determines which channels
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are capable of being descrambled by the cable box.
Preferably, this is accomplished by referring back to the
channels temporarily stored as "scrambled" when scanning
the direct cable input, then tuning the cable box to those
channels to see if they have been descrambled, preferably
by confirming that horizontal sync is now periodic and non-
inverted. As an alternative technique, the system can
simply scan the entire spectrum of channels available from
the cable box and store them as tunable or non-tunable to
be skipped, without regard to whether they have been
descrambled by the cable box. This would eliminate the
need to temporarily store and re-reference scrambled
channels detected on the cable.
In operation, the present invention knows the
status of system resources and keeps a running tab of all
tunable channels. The table of Figure 5 lists attributes
of a few channels as they may be organized within RAM 107.
A "1" in the table denotes that the tuner associated with
the unit listed in that column is capable of tuning program
material on that channel. For example, as shown in the
first row, only the cable box 24 is capable of tuning
channel 02, which would be the case if channel 02 is a
scrambled channel. The second row shows that none of the
tuners can find program material on channel 03, which is ,
usually the case. The third column shows that all system
tuners (44, 46, 70) are capable of tuning channel 04.
Thus, if a viewer wished to watch channel 02,
that command would be received by user input 102 and
transferred to controller 100. Controller 100 would then
r
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place switch 96 in position "A" and cause IR transmitter
108 to send a -0--2- channel-select control signal to the
cable box and a -0--3- channel-select control signal to the
TV.
If more than one tuner is capable of tuning a
particular channel, as is the case with channel 04 in
Figure 5, selection of that channel for viewing would
preferably cause all tuners to tune to that channel.
Controller 100 would place switch 96 in position " C" and
cause the TV to tune channel 04 directly from the cable.
In this way, if a "RECORD" command were subsequently
received by an operator, it would be interpreted to mean
record channel 04. Switch 48 would be controlled to
position "2," and the tape unit would be activated.
Since the controller 100 stores the status of
recording and viewing from all channels, it could inform
the operator if a particular request is not possible. For
example, if the tape unit is recording a premium channel
from the cable box and the user selects a different premium
channel for viewing, the invention would send a message to
the screen indicating that the only resource capable of
tuning that premium channel is in use, and that the
recording process would need to be halted to view it. In
the event the viewer selected the same pay channel for
viewing and recording, the controller would cause switch 96
to select position "B."
Referring to Figure 6, remote control transmitter
300 of the present invention is specially designed to
ensure that the control codes subsequently transmitted to
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the non-VCR components in accordance with the single user
command are accurately received and understood. Thus,
unlike conventional remotes, which typically send a '
continuous stream of the same code until the operator
removes his finger from that button, the remote dedicated
to the VCR of the present invention will preferable send a
single code (or just a few repeats of the same code),
followed by a delay to afford subsequent re-transmission of
control signals by the IR transmitter 108 to the cable box
24 and/or TV 26. If the button is depressed for an
extended time, as would be the case with volume control or
channel slew, commands the VCR remote will again transmit
only one or a few codes, followed by a delay, thereby
affording the VCR another opportunity to re-transmit, and
so on, until the operator's finger is lifted.
In an alternative embodiment, a different IR
frequency could be used for the dedicated VCR remote or,
eliminates "wait states," an RF link could be used for the
VCR remote, thus enabling the receipt of user commands and
the re-transmission of cable-box and TV directives to occur
simultaneously.
Since the VCR 22 stores the identities of all
tunable channels and the status of all system resources, it
also allows the user to continue to use the remote-control
devices that came supplied with the cable box or TV, and
operates to avoid potential interference problems.
Generally speaking, if the VCR 22 senses a command from a
remote other than the one dedicated to the VCR, it will
interpret the command and, if executable, carry out the
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Command. If the commal7d would bring about a1n undesirable
result, however, the present' invention will allow the
Command to be executed and them ~.mmediately send bits own IR
signal tc reverse the ac'tiQn of the ~prev~,ous command.
Figure 7 is an 311us~tratipn of the interaction
among system components upon receipt of a command issued
from a remote--control transmitter dedicated to a system
resource other than the VCR, such as the television
receiver 26. Assume that the Tv zs is tuned to channel 1i
1o directly from the cable and a channel-up command is
trarisxaitted from the TV' s old remote. Aautrie further that
channel 12 is a st~rambled channel. The TV cannot
accommodate this request, because if it simply increments
the TV tuner it will rec6:ive Channel Z2 from the cable
feed, Which will be sora~fibled. The controller 100 will
then automatically re-tt~he the TV to channel -0--3-, tune
the cable box to-1--2- and make sure that switches 49 and
94 are set appropriately within the VCR. Generally
speaking, assuming the 'Gape unit is nQt tying up the
2o requested ~ssource, if a channel rer~uest command is
received by the VCR 22, the system will operate to provide
that,~ha,nnel from whichever resource has the capability of
tuning it.
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