Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
2179474
METHOD AND APPARATLJg FOR SELECTIVELY BLOCKING
This invention relates to apparatus and methods for
selectively blocking the reception of video signals in response to
information which is encoded in the signals. The method and apparatus
of the invention have particular application in controlling the content of
television programnvng that can be displayed on a television.
Television viewers are faced with an increasingly diverse
selection of programs to choose from. Some programs contain content
which some viewers may consider to be offensive or which contain
material which is inappropriate for children. There is a need for an
effective way to block offensive or inappropriate material from being
viewed.
2o As the number of available television channels increases it is
becoming increasingly difficult for television viewers to locate and select
programming that interests them from the many programs that may be
completely uninteresting. There is a need for a system which would allow
a television viewer to limit the selection of programs available for viewing
to those programs which match the viewer's preferences.
Vogel, U.S. Patent No. 4,930,160 discloses methods and
apparatus for automatically censoring video programs. If a classification
z ~ ~9~.~4
i
-2-
code encoded in the video or audio portion of a video signal matches a
stored classification code then an alternative video signal is displayed.
Elam, U.S. Patent No. 4,554,584 discloses a circuit for blanking
the audio and video portions of a video signal in response to digital code
words transmitted in the video signal. The code words are transmitted as
ASCII codes in line 21 of the video signal. The picture and sound are
blanked whenever the received ASCII code matches or exceeds a value
selected by the user.
Lemelson, U.S. Patent No. 5,387,942 discloses a system which
would allow parents to block the reception of television programming
which they consider to be inappropriate for their children. Lemelson
discloses a video reception control unit. The control unit responds to 3-
digit binary codes embedded in a received video signal. The codes indicate
respectively whether or not the program content of the received video
signals includes violence, coarse language and nudity. A viewer can set
the control unit to block transmission of the received video signal to a
television whenever all, or selected ones, of the codes indicate the presence
of adult subject matter. The control unit is lockable to prevent determined
children from tampering with its settings.
Other prior art video blocking systems and related systems
and methods are disclosed in the following United States patents: Chard
4,605,964; Olvio Jr., 4,888,796; OIvio Jr. 5,172,111; Kwoh et a1. 5,382,983;
Hunter Et al., 5,485,418; Banker et al. 5,477,262; Voge1 et al., 4,930,158;
Nafeh 5,343,251; Choi, 5,270,822; Keene 5,450,122; Vogel, 5,253,066; Vogel
5,371,795; Copriviza et al. 5,319,453; Graves et al. 5,410,344; Palmer.
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5,195,135; Kamijyo, 5,053,884; Von Kohorn, 4,520,404; Hoffart, 5,341,216;
Thomas et al. 5,425,100; Nadan 5,321,750; Hori, 5,386,240; Vogel, 5,446,488;
Iggulden et al. 5,333,091; Robertson et al. 5,361,301; Kawashima et al.,
5,307,165; Diehl et al., 5,373,557; Coutrot et al., 5,301,233; Sussman
5,369,440; and Minot et al. 5,455,892.
Summary of the Invention
As noted above, the prior art includes various devices which
block reception of an incoming video signal when a code encoded in the
signal matches a code stored in the device. A problem that the inventor
has identified with all such prior devices known to the inventor is that the
prior art blocking devices must be constructed or initially programmed
with advance knowledge of the meanings of the codes which may be
embedded in the incoming video signal. Where different coding schemes
are used in, for example, different geographical regions and a blocking
device is moved from one region to another or where new coding
schemes are introduced to replace or supplement existing coding schemes,
then the prior art units must be rewired or reprogrammed. This can be
extremely expensive because very many blocking devices will be affected.
Further, previous systems cannot readily provide selective blocking where
different coding schemes are used for different programs or on different
channels that may be received in a particular location.
Accordingly, this invention provides in one aspect a method of
selectively blocking a video signal comprising the steps of:
(a) configuring an apparatus in accordance with a first
informational scheme;
(b) configuring the apparatus in accordance with a second
informational scheme, said second informational scheme
being distinct from said first informational scheme;
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(c) storing, in the apparatus, user preference information for
selectively blocking programs described according to said
first informational scheme;
(d) storing, in the apparatus, user preference information for
selectively blocking programs described according to said
second informational scheme;
(e) receiving, at the apparatus, a video signal having program
content information embedded therein, said program
content information being encoded according to either
said first informational scheme or said second
informational scheme;
(f) comparing said program content information to the user
preference information for the informational scheme
according to which said program content information is
encoded to determine whether to block the presentation of
said video signal, at least in part; and
(g) if the presentation of said video signal should be blocked
as determined in step (f), blocking the presentation of said
video signal, at least in part.
In another aspect the invention provides a method of enabling
a television viewer to selectively block television programming from
different television sources, said method comprising the steps of:
(a) obtaining a first television program having first program
content information embedded therein, said first program
content information being encoded according to one of a
plurality of informational schemes;
(b) obtaining a second television program having second
program content information embedded therein, said
second program content information being encoded
according to another of said plurality of informational
schemes;
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(c) simultaneously transmitting, to said viewer, said first
television program on a first television channel and said
second television program on a second television
channel;
(d) at said viewer, receiving either said first television
program or said second television program and extracting
the program content information corresponding to the
received program; and
(e) at said viewer, automatically comparing the extracted
program content information to user preference
information corresponding to the extracted program
content information to determine whether to block the
presentation of said video signal, at least in part.
In another aspect the invention provides a method of
selectively blocking a video signal comprising the steps of:
(a) receiving, at an apparatus, a set of configuration
information describing an informational scheme, said set
of configuration information having been embedded in a
remotely transmitted configuration signal;
(b) configuring said apparatus in accordance with the set of
configuration information;
(c) storing, in the apparatus, user preference information for
selectively blocking programs described according to said
informational scheme;
(d) receiving, at the apparatus, a video signal having program
content information embedded therein, said program
content information being encoded according to said
informational scheme;
(e) comparing said program content information to the user
preference information to determine whether to block the
presentation of said video signal, at least in part; and
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(f) if the presentation of said video signal should be blocked
as determined in step (f), blocking the presentation of said
video signal, at least in part.
In another aspect the invention provides an apparatus
for
selectively blocking
a video signal
comprising:
(a) a memory for storing
(i) a first set of configuration information
describing a
first informational scheme,
(ii) a second set of configuration information
describing a
second informational scheme, said second
informational scheme being distinct from said
first
informational scheme,
(iii) a first set of user preference information
for
selectively blocking programs described according
to
said first informational scheme, and
(iv) a second set of user preference information
for
selectively blocking programs described according
to
said second informational scheme;
(b) an input for receiving a video signal having
program
content information embedded therein, said
program
content information being encoded according
to either
said first informational scheme or said second
informational scheme;
(c) an output for providing an audio and video
presentation
of said video signal;
(d) a decoder coupled to said input for extracting
said program
content information;
(e) a processor coupled to said decoder and to
said memory
for comparing said extracted program content
information
to the user preference information for the
informational
scheme according to which said program content
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information is encoded; and
(f) blocking means operatively coupled between said
processor and said output for selectively blocking the
presentation of said video signal at said output, at least in
part, in response to the comparison performed by said
processor.
In another aspect the invention provides a method for
selectively blocking a video signal comprising the steps of:
(a) configuring an apparatus in accordance with two or more
informational schemes;
(b) receiving, at the apparatus, a video signal having program
content information embedded therein, said program
content information being encoded according to at least
one of said two or more informational schemes; and
(c) blocking presentation of at least part of the video signal or
displaying the video signal based on said program content
information relative to user preference information.
In another aspect the invention provides a method for
selectively blocking a video signal comprising the steps of:
(a) configuring an apparatus in accordance with one or more
informational schemes;
(b) receiving, at the apparatus, a video signal having program
content information embedded therein, said program
content information being encoded according to at least
two or more informational schemes including the one or
more informational schemes in step (a); and
(c) blocking presentation of at least part of the video signal or
displaying the video signal based on said program content
information relative to user preference information.
In another aspect the invention provides an apparatus for
CA 02179474 2000-02-21
selectively blocking a video signal comprising:
(a) a memory storing data representing two or more
informational schemes;
(b) a switch for coupling to a display unit, said switch
receiving a video signal having program content
information embedded therein, said program content
information being encoded according to at least one of said
two or more informational schemes; and
(c) a processor coupled to the memory and the switch, said
processor comparing said program content information to
said stored data and outputting a blocking signal in
accordance with said comparison.
In another aspect the invention provides an apparatus for
selectively blocking a video signal comprising:
(a) a memory storing data representing two or more
informational schemes;
(b) a detector detecting encoded data embedded in a video
signal and outputting the encoded data, said encoded data
representing program content information embedded in
the video signal, said program content information being
encoded according to at least one of said two or more
informational schemes; and
(c) a processor coupled to the memory and the detector, said
processor decoding said encoded data to determine said
program content information, said processor comparing
said program content information to said stored data and
outputting a blocking signal in accordance with said
comparison.
In another aspect the invention provides an apparatus for
selectively blocking a video signal comprising:
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(a) a memory storing data representing two or more
informational schemes; and
(b) a processor coupled to the memory, said processor
detecting encoded data embedded in a video signal
representing program content information encoded
according to at least one of said two or more informational
schemes, decoding said encoded data to determine said
program content information, comparing said program
content information to said stored data and blocking
display of the video signal in accordance with said
comparison.
Brief Description of the Drawings
In drawings which illustrate non-limiting preferred
embodiments of the invention,
Figure 1 is a block diagram showing video blocking apparatus
of the invention connected between an incoming video signal and a
television;
Figure 2 is a block diagram of video signal blocking apparatus
according to the invention;
Figure 3 is a drawing of an on screen display produced when a
video signal is being blocked;
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Figure 4 is a drawing of an infrared remote control transmitter for
controlling the operation of the apparatus of Figure 2;
Figures 5A through 5I are examples of on screen menu displays that
could be produced by the apparatus of Figure 2; and,
Figure 6 is an example of an informational screen display that may
be produced by the apparatus of Figure 2.
Detailed Description of the Preferred Embodiment
In the invention, as shown in Figure 1, information about
video programnning being carried in a video signal 24 is encoded and the
encoded information is embedded in video signal 24 by a broadcaster 26.
An apparatus 20 retrieves and decodes the embedded information.
Apparatus 20 is in the signal path between the broadcaster 26 and a
viewers television screen. If the decoded information matches stored user
preferences stored in a memory means in, or otherwise accessible to,
apparatus 20 then apparatus 20 blocks the video component of video signal
24 from being displayed on a video display means, such as the viewer's
television monitor 22, and also preferably blocks any audio component of
2o video signal 24 from being played. This provides the viewer, or the
viewer's parent or guardian, with some control over the television
programming that the viewer can be exposed to. In t$e alternative,
apparatus 20 may permit viewing of video signal 24 only if the decoded
information matches certain stored user preferences.
Incoming video signal 24 may be delivered to apparatus 20 by
satellite, by cable, by VHF or UHF broadcast or in any other suitable way.
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Incoming video signal 24 may also be the output from a video playback
device, for example, a video cassette recorder ("VCR") or a laser disk
player. In the latter case, the "broadcaster' 26 is the party who provided
the recorded signal which is played back to create incoming video signal
24.
Apparatus 20 is preferably built into a television set 22 but
may also be provided as a stand-alone unit. Where apparatus 20 is
provided as a stand-alone unit suitable locking means are provided to
1o prevent the operation of apparatus 20 from being frustrated by routing
incoming video signal 24 so that it bypasses apparatus 20.
As shown in Figure 2, apparatus 20 has inputs 32 for one or
more signals, such as composite audio and video signals, which comprise
incoming video sisal 24. Inputs 32 may be connected, for example, to the
audio and video outputs from a VCR, a television tuner, or a cable
converter. Inputs 32 are preferably buffered to prevent unnecessary loading
of the source of video signal 24. Apparatus 20 also has an output 34 which
may be connected to the video input of a television set. Switching means
36 and 38 are connected between inputs 32 and output 34. Separate outputs
(not shown) for composite video and composite audio and/or other signal
formats) may also be provided in addition to or instead of a single output
34.
When apparatus 20 is not blocking a signal then switching
means 36 and 38 are ON so that video from inputs 32 passes through
switching means 36 and 38, through rf modulator 39 and out of output 34.
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RF modulator 39 combines the audio and video signals from inputs 32
into a rf signal which can be received by a standard television set.
Switching means 36 and 38 are preferably electro-mechanical relays or
electronic switches but may be any other switching means capable of
preventing incoming video signal 24 at inputs 32 from being passed to
output 34 in a form capable of being viewed on the screen of television 22.
Switching means 36 and 38 may even be switchable filters or other
apparatus which degrades signal 24, or adds noise to signal 24, to the point
that signal 24, is no longer capable of being viewed on the screen of
television 22 when it exits apparatus 20.
When apparatus 20 detects one or more embedded codes in
video signal 24 that represent information which indicates that video
signal 24 should be blocked then apparatus 20 turns switching means 36
and 38 OFF, as described below, thereby preventing video signal 24 from
reaching output 34. When video signal 24 is being blocked, video
switching means 38 may connect to an alternative video signal, for
example a signal containing a graphic which indicates that video signal 24
is being blocked. The graphic may optionally provide details about the
program being blocked, such as its title etc. Preferably switching means 36
and 38 are OFF when apparatus 20 is not powered so that the operation of
apparatus 20 cannot be defeated by disconnecting apparatus 20 from its
power source.
Information about the program content of a received video
signal is preferably embedded and encoded as digital data packets which are
transmitted with the video signal. The data packets are inserted by
broadcaster 26 or by a cable company who retransmits video signal 24.
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In the preferred embodiment of the invention, the data packets
are embedded in video signal24 by transmitting them during the video
blanking interval of video signal 24. In North America, the video blanking
interval comprises lines 10 through 21 of a video signal. Most preferably,
the data packets each comprise data bytes transmitted in the Extended
Data Services ("XDS") portion of a video signal. XDS data is transmitted
i n line 21 of the video signal as defined by Electronic Industries
Association
specification No. EIA-608, as is well known. It is desirable to use line 21
because almost all new television sets sold in the North America are
required to have a built-in decoder for XDS data transmitted on line 21.
Specification No. EIA-608 specifies protocols for embedding
digitally encoded information packets containing information about a
television program which is being currently broadcast. Each XDS data
packet begins with a "start" character which also indicates the "class" of
the information (i.e. generally what the information in the packet relates
to). For example: the start character for data about a current program (the
"Current" class) is Olh; the start character for data about the current
channel (the "Channel Information" class) is 05h; and, the start character
for "undefined" data (the "Undefined" class) is ODh. A data type character
which indicates the specific nature of the information being transmitted
follows the start character. Each information packet ends with an "end"
character, which is defined in EIA-608 to be OFh, and a checksum character.
EIA-608 defines codes for transmitting some information that
is useful for practising the invention. Other information for practising the
invention can be conveniently transmitted as XDS data using the undefined
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data type provided by EIA-608, as discussed below. Of course, this or
similar information could also be encoded and transmitted in ways which
do not conform with the EIA-608 specification. It will be readily apparent
to those skilled in the art that the invention could be practised with other
protocols and/or by encoding and embedding any necessary data in video
signal 24 using other encoding and/or embedding techniques. What is
important is that the incoming video signal 24 have somehow embedded
in it codes which convey at least some of the information described below.
1o Table I lists some types of XDS data which are defined by EIA-
608 and are useful in the invention.
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TABLE
I -
XDS
Data
Types
Start Size of
Char. ~g Da a
Char. (Bvt~es)r
Olh 02h 2 Duration: Length of show (hours
and
minutes)
01h 02h 2 Time-in Show: Elapsed time in
program (hours and minutes)
Olh 03h 2-32 Title: Title of program (up to
32
standard ASCII characters)
01h 04h 2-4 Type: A keyword describing the
type
of program e.g. "horror', "comedy",
"talk show", "news' etc.
01h 05h 2 Rating: Motion Pictures Association
of
America ("MPAA") or Canadian
Motion Picture Distributors
Association ("CMPDA") (or
equivalent) rating
1o Olh 10h to Advisory: Consists of key words
or
1711 short key phrases that describe
the
subject matter and content of
a
television program.
05h 02h 4 Call Letters: Call letters of
local
broadcaster
07h 01h and 4-6 Time: Time of day
04h
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Information about a program may include category
information, which identifies a level assigned to the program in each of one
or more categories. An example of a category is the "Rating" information
described in Table I. Each program may be assigned a rating which ranges
kom, for example, "Exempt" to "X-Rated" through a series of intermediate
levels. Information about a program may also be provided in the form of
labels which may be used to indicate whether certain subject matter is
present in the program. For example, labels may include things such as
"Action", "Drug-use', "Adult", "Tallc-show" etc. An informational scheme
may include several groups of labels. Different groups may describe
different aspects of a program or may contain labels assigned by different
rating organizations. The data types "Type' and "Advisory" which are
specified by EIA-608 are examples of groups of labels that may be assigned
to video programs. An informational scheme may provide one or more
groups of labels not specified by EIA-608 in addition to or instead of the
labels specified by EIA-608.
In addition to some or all of the predefined data types
described above, the preferred embodiment of the invention provides
embedded codes containing a category information which describes a level
assigned to the currently broadcast program according to at least one
additional category. For example, in a preferred embodiment of the
invention, the current program is rated in each of three categories in
respect of its levels of violence, sexuality and coarse language. Category
information in respect of these three scales can conveniently be transmitted
as XDS data in unused parts of the "Rating" data packet (start character
05h) of the Current class. In the alternative, this additional category
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information could be transmitted as data in the XDS "Undefined" class, or
may be otherwise transmitted.
The inventor has found that it is generally desirable to provide
category information on a graduated scale in which the lowest level of the
scale describes unoffensive program content and the highest IeveI of the
scale indicates program content that many viewers would find highly
offensive. Between the highest and lowest levels on the scale are
intermediate levels. Most preferably each scale contains between 3 and 7
levels. This provides sufficient flexibility and yet rn;n;m;~es the amount of
effort required for broadcaster 26, or a rating organization, to assign a
level
or levels to the program in each category and is not overly complicated for
a viewer to understand or set up.
As a 3-bit binary number can have 8 possible values, a data
packet containing two 7-bit characters can store category information for
a program in 4 independent categories each having up to 8 levels. For
example, Table II illustrates a combination of four categories that could be
applied to a television program. The meanings attributed to the levels in
2o each category are defined by the persons or body that sets standards for
the
category in question. For example, Table III explains possible meanings of
the levels in the "Rating" category of Table II.
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TABLE II
- EXAMPLE
CATEGORIES
DATA RATING VIOLENCE LANGUAGE SEXUALTTY
(c) (v) (1) (s)
0 Exempt none none none
1 General comedic suggestive mature
themes
2 PG mild mild brief nudity
3 Adult brief coarse mild
sexuality
4 Restrictedstrong strong full nudity
5 X-Rated graphic explicit sexual
activity
The category information of Table II may be encoded in two 7-bit
characters, charl and chart. For example, this may be done as follows:
bit6 bits bit4 bit bit2 bitl bit0
3
charl 1 v2 v1 v0 c2 cl c0
chart 1 s2 sl s0 12 11 10
v2, vl and v0 are the values of the three bits which indicate the level in the
violence category of violence in the program; s2, s1 and s0 are the values
of the three bits which indicate the level in the sexuality category of
2o sexuality in the program;12,11 and 10 are the values of the three bits
which
indicate the level in the language category of coarse language in the
program; and c2, cl and c0 are the values of the three bits which indicate
the level in the rating category,of the rating for the program. Each of chart
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and chart has a value between 40h and 7Fh. For example, a "PG" program
(c=2) with comedic violence (v=1) suggestive language (1=1) and brief
nudity (s=2) would have bits allocated to charl and chart as follows:
bit6 bits bit4 bit bit2 bitl bit0
3
charl 1 0 0 1 0 1 0
chart 1 0 1 0 0 0 1
TABLE
III -
CLASS
RATING
(c)
1o LEVEL RATING DESCRIPTION
(C)
0 E Exempt - news , sports , documentaries
etc.
1 G General Audience - suitable for viewing
by
all ages
2 PG Parental Guidance advised below 13
years of
age - Themes may not be suitable for
children. May contain brief violence,
coarse
language and/or mature themes
3 A Adult - suitable for persons 16 years
of age
and older. Those under 16 should view
with
an adult. will likely contain violence,
strong
language and/or nudity.
4 R Restricted to 18 years of age and older-
content not suitable for those under
the age
of 18. contains graphic violence, explicit
language and/or sexual activity.
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Information about the content of video signal 24 could also be
encoded and embedded in video signal 24 as ASCII strings and transmitted
in over one of the text channels (T1 or T2) which are also defined in EIA-
608. -If embedded codes are to be transmitted on a text channel then,
preferably, each embedded code consists of a pair of delimiter characters,
which respectively identify the start and end of an embedded code, a data
identifier, which identifies the meaning of data in the embedded code and
some data. The characters in the embedded code are preferably selected
from the ASCII symbols.
For example, an embedded code could contain the 4 ASCII
characters "<V4>". 'The delimiter characters "<" and ">" indicate the start
and end of the embedded code respectively. The data identifier "V" could
indicate that the accompanying data indicates the level in the violence
category of violence in the program content of the received video signal 24.
The numeral "4" indicates that the violence level is 4 on a scale of, for
example, 0 to 5. Where embedded codes are transmitted in a text channel
then, for example, a film rated "Adult" with an advisory for brief violence,
mild language and brief nudity could have embedded in it, among others,
the codes <C3> <V3> <L2> <S2>.
If embedded codes are transmitted on a text channel in which
other textual information is also being transmitted then each embedded
code should consist of a sequence of characters that is very unlikely to
occur in any other data in the channel being used to transmit the
embedded codes.
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Each different type of embedded code can be transmitted by
broadcaster 26 at a different rate. XDS data transmitted according to EIA-
608 has a maximum throughput of about 60 characters per second.
Consequently, where data packets are transmitted as XDS data on line 21
of video signal 24 the relevant program information should occupy no
more than about 100 7-bit characters to ensure that all of the desired
information can be broadcast in embedded codes which are repeated every
2-4 seconds.
1o The amount of data that must be transmitted to describe a
program can be reduced by transmitting information, such as labels which
are selected from a predefined list, by transmitting only an index which
identifies the position of the Label in the list. For example; if in a list of
labels "Action' is the tenth label, then the label "Action' can be
transmitted by setting the tenth bit in a block of transmitted data or by
otherwise transmitting data representing the index "10" (which can be
encoded as one character or less) instead of the string "Action' (which
occupies 6 characters). If the program information includes category
information relating to one or more mufti-level categories of mufti-level
information which can have one of several levels then it is only necessary
to transmit an integer indicating the level for the current program, as
described above. It is not necessary to transmit the descriptions for each
different level in the category or even for the current level in the category.
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As data packets are received in apparatus 20 they are detected
by data slicer 40 which may be, for example, a 86129 data slicer and on
screen display chip available from Zilog Corporation. In the preferred
embodiment of the invention data slicer 40 is a line 21 decoder. Data slicer
40 is connected to video input 22 and monitors received video signal 23.
The operation of apparatus 20 is coordinated by a
microprocessor 42, which runs a software program 54 stored in a memory
means accessible to microprocessor 42 such as ROM 43. Microprocessor 42
may, for example, be a Motorola 6805 microprocessor. The particular
circuitry associated with microprocessor 42 and the circuitry for interfacing
microprocessor 42 to other devices, such as ROM 43 and the other parts of
apparatus 20 can have many variations and is well known to those skilled
in the art and is therefore not described herein.
Each time data dicer 40 detects and decodes a character in the
received video signal it transmits the character to microprocessor 42 over
data bus 44 and triggers an interrupt in microprocessor 42. Triggering the
interrupt causes microprocessor 42 to execute an interrupt handler routine
which interprets the received character. The following pseudo code
illustrates the operation of the interrupt handler routine. In pseudo-code
in this application: get(operandl, operand2) is a function that fetches data
from either the IR receiver 65 or data slicer 40. Operand 1 specifies the type
of data that is expected. The retrieved data is stored in the variable
identified by operand2; convert(time_of_day) converts a string of ~6
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characters which represents the time of day and converts it into a number
in the range of 1 to 1440 representing the minute in the day;
load user(operandl) retrieves the data which is identified by operandl
from non-volatile memory; display(operand) uses on screen display
generator 60 to display information pointed to by operand on a display
means, such as the screen of television 22; update(operand) adds a station s
call letters, a program title, or a range of viewing times to a list of
restricted
call letters, program titles, or viewing times; change(operandl,operand2)
changes operandl by the amount specified in operand2; toggle(operand)
1o switches the value of the variable identified by operand between 2 values;
arid parse is used to parse incoming classification information and is
described more fully below.
XDS Data Receive Algorithm
~5 XDS_begin;
get(Start, Type); ' Start is the character that identifies the XDS class
'Type is the character that identifies the meaning
'of the data within the class
* Current Class
ao if Start=01 ~
begin
j,~ Type=02 ~g get(string, duration + time_in_show);
jf Type=03 ~ get(string, title);
'get index which identifies label
jf Type=04 get(index, type(T_type));
'retrieve category information
f Type=05 ~ for N=1 to number of categories
2179474
begin
get(n_level(N), classification); 'n_level(N) is an array
parse(configuration, classification);
end;
end;
* Channel Information CIass
j~ Start=05
f Type=02 ~ get(string, channel); 'retrieve call letters of station
* Miscellaneous Qass
~ Start=07 ~g
if Type=01 ~ get(string, time of day);
clock=convert(time_of_day); 'set internal clock
* Undefined CIass
if Start=OD ~
begin
if Type=05 get(string, configuration);
XDS_end; -
As data packets are received by data slicer 40 and transmitted
2o to microprocessor 42, the intemzpt routine parses the retrieved data and
stores the received data in memory locations 52 in RAM 46 according to the
data identifier in the encoded information. For example,: one memory
location 52 stores the current value of the level in the violence category
"V" for the current program; another memory location 52 stores the call
letters of broadcaster 26, another memory location stores the current value
of the level in the language category "L" for the current program, another
2179474
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memory location 52 stores a list of the labels which describe aspects of the
program etc.
Each time an embedded code data packet is received,
microprocessor 42 simply determines what type of information is stored in
the received data packet and overwrites the memory locations) 52
corresponding to that type of information with the data in the received
data packet. Microprocessor 42 may use configuration information stored
in apparatus 20 which specifies how the encoded information is organized
1o in the received data packet to separate different types of information
stored
in the data packet before storing the information in memory locations 52.
For example, in a preferred embodiment of the invention
category and label information is transmitted in a single XDS data packet.
Category information for a number of categories is transmitted first (with
information about two categories transmitted in each 7-bit character as
described above) followed by label information (with one character
specifying a label). The characters used to specify label information are in
the range 20h to 3Fh. The character 20h specifies the first label, the
2o character 21h specifies the second label, and so on. An XDS data packet can
contain up to 32 characters so, if 4 characters are used to transmit category
information, then 28 characters are available for transmitting label
information.
Apparatus 20 has stored in it configuration information which
identifies the number of mufti-level categories and the number of labels
being used. If, for example, the configuration information indicates that
2119474
-25-
there are 5 categories, then apparatus 20 treats the first 3 characters in the
data packet as being category information (5 categories each having 8
levels or less can be encoded in 3 bytes as described above) and the rest of
the characters in the data packet are treated as specifying labels.
If a broadcaster 26 transmits at least one of each type of
embedded code about every 2 to 4 seconds then the data stored in memory
locations 52 will not be more than about 4 seconds old. The content of
embedded codes cauld change throughout a television program to permit
1o blocking of certain offensive scenes only.
Preferably, whenever microprocessor 42 receives an embedded
code cantaining station identification information (e.g. the call letters of a
broadcaster 26) then microprocessor 42 compares the newly received call
letters to the previously stored call letters. If the newly received call
letters
are different from the call letters stored in RAM 46 then the viewer must
have selected a different channel. Microprocessor 42 then erases the
information stored in memory locations 52 in RAM 46. This eliminates the
problem that could be caused if a viewer switched from, for example,
watching a program on one channel with extreme violence V=6 to a new
channel with no coding for violence. If there were no new data to overwrite
the violence level stored in RAM 46 then the viewer could be blocked from
viewing the new channel too.
Because embedded codes do not need to be transmitted at
specific times, the embedded codes can be transmitted when space is
available. If the embedded codes are being transmitted in line 21 of an
2179474
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incoming video signal 24 and other data is also being transmitted on line
21 (for example captions in a different language) then the embedded codes
can be buffered. If line 21 of the video signal is full in one frame of the
video signal then the embedded codes which were ready to be transmitted
with that frame can be saved and transmitted in Line 21 one or more
subsequent frames of the video signal. This guarantees that the embedded
codes do not interfere with the transmission of other data in line 21 of the
video signal.
1 o While a user is watching television 22 then microprocessor 42
runs a main portion of software program 54, as illustrated by the following
pseudo-code:
Main Program 54
Main begin;
Initialize data_slicer;
Initialize OSD;
Configure interrupt sources (XDS, IR);
Load_configuration_data; 'load configuration information
'load previously stored user preferences
2o Load user(cat setting(N cat)); 'category preference information
Load user(label_list(N cat+1)); 'label preference information
'label preference information (in the "type' group of labels)
Load_user(type_list(N_type));
Load_user(channel_list(N channel)); 'list of channels to block (or permit)
Load_user(title_list(N title)); 'list of program titles to block(or permit)
Load_user(viewing_times); 'allowable viewing times
Load user(allowance); 'daily viewing allowance
While (T'V_On > 0) do
2179474
_27_
begin
Block = Off; 'default is that video signal 24 can pass
'block video signal 24 if any of the
'following conditions are met
~ i=1 to N_cat s~.g
i~ (cat(i) > cat setting(i)) I~ Block = On;
~ i=1 to N cat+1 ~
fg~ j=1 to L_type ~
(label(j) E label list(i)) ~g Block = On;
~ i=1 to N_type ~
o~ j=1 to T type ~
if (type(j) a type list(i)) ~ Block = On;
~ i=1 to N channel ~g
(channel a channel list(i)) 11~ Block = On;
~ i=1 to N title ~
j,f (title a title_Iist(i)) ~ Block = On;
,~ (clock a viewing_times) ~ Block = On;
i~ (TV_On > allowance) t~ Block=On;
'display alternative image when BIock=On (video signal 24 is blocked)
'by switching switching means 38 and generating blocking screen with
'on Screen display 60
j~ (Block = On) ~ display(Block Screen);
gl~g, display(normal);
end;
as
Under the control of software program 54, microprocessor 42
compares the data stored in memory locations 52 with corresponding user
2179474
preference information stored in, or loaded from, memory locations 56 in
non-volatile memory means 58. Any suitable compatable non-volatile
memory, for example, flash RAM ("FRAM"), electrically erasable
programmable ROM ("EEPROM") or a magnetic storage medium, may be
used for non-volatile memory means 58.
When program 54 detects that memory locations 52 contain
data which is outside the bounds prescribed by the corresponding memory
locations 56 then program 54 causes microprocessor 42 to turn switching
means 36 and 38 OFF. When switching means 38 is fumed OFF it
optionally connects an alternative video signal, such as a display created
by an on screen display generator 60, to output 34. Figure 3 shows an
example of such a display. The display of Figure 3 provides information
about the program which is being blocked. This information is available
from memory locations 52.
An on screen display generator 60 is commonly incorporated
on a single chip with a data slicer 40. On screen display generator 60 can
generate and display on the screen of television 22 displays which, for
2o example, provide information about a current program, indicate that a
program is being blocked, indicate the current configuration of apparatus
20, and/ or guide a user in setting up and configuring apparatus 20.
Apparatus 20 includes input means, which can be any means
which allows a user to send information to apparatus 20. In the currently
preferred embodiment of the invention, the input means includes an
infrared remote control transmitter 71 which transmits control signals to an
CA 02179474 2000-02-21
- 29 -
infrared receiver 65 in apparatus 20. When infrared receiver 65 receives a
control signal from infrared transmitter 71 it interrupts processor 42.
Software running in processor 42 can then retrieve and interpret the
transmitted information.
Preferably a user can override the blocking function of
apparatus 20 by entering a password, or identification number, ("PIN").
This permits those who know the PIN to watch an individual television
program that apparatus 20 is configured to block without reprogramming
apparatus 20. At the end of the program (or after a time period) apparatus
resumes its normal function. Apparatus 20 can detect when a program
is over by monitoring data packets containing the title or identification
number for the current program.
15 CONFIGURATION
Apparatus 20 must be able to recognize the various
information that is encoded and embedded in video signal 24. If all
programming were described everywhere according to a universal
20 informational scheme, which never changed, then apparatus 20 could be
preprogrammed to recognize all of the types of information about video
signal 24 in that universal scheme. It is highly unlikely that a universal
rating scheme could be agreed upon. People in different countries, and
even people in different parts of the same country have differing. views
regarding what information is appropriate for selecting programming to
view and what typed of subject matter might be considered to be offensive.
The present invention provides a video and blocking system capable of
dealing with and blocking programs that may be coded according to two or
more distinct information schemes. Preferably, the invention provides a
method and apparatus to remotely
CA 02179474 2000-02-21
- 30 -
configure apparatus 20 to accommodate new schemes for selecting and
transmitting information about video signal 24 that may be introduced to
augment or replace existing schemes. This makes it unnecessary to
physically alter apparatus 20 if a new informational scheme is adopted.
In accordance with this preferred embodiment, broadcaster 26
transmits configuration information which describes the scheme of
information about video signal 24 used by broadcaster 2 6 . The
configuration information is preferably encoded and embedded in video
signal 24 in the same manner as the codes which contain information
about video signal 24 are encoded and embedded. When configuration
information is received by apparatus 20 it is identified as such by, for
example, its XDS data type. The configuration information identifies: the
number of categories (0 or more) and the number of levels within each
category in the informational scheme; the number of groups of labels (0 or
more) and the number of labels in each group. This information is used
by apparatus 20 to allocate locations in non-volatile memory means 58 to
store user preference information corresponding to each category and each
group of labels in the informational scheme. The information is also used
when apparatus 20 is initialized to allocate memory locations 52 in RAM
46 to store the received category information and label information.
Preferably the configuration information provides descriptive
names of the different categories of multi-level information in the
informational scheme (e.g. violence, sexuality, language etc.); descriptive
names for each level within each category (e.g., for the violence category:
none, comedic, mild, brief, strong, graphic etc.); and some or all of the
CA 02179474 2000-02-21
-31 -
descriptive labels used in the informational scheme. This information can
be provided to a user to assist the user in providing user preference
information for storage in apparatus 20. In general, it is easier for a user
to
select between blocking programming in which the level of violence is
"strong" or "graphic" than it is to select between levels "4" and "5".
Configuration information is preferably transmitted in a
separate channel so that it does not interfere with program related
information. Most cable television networks have a "barker" channel
which does not require much of its own information because it merely
displays a schedule of television programs which are available for viewing
on other channels of the cable network. In a cable television network,
configuration information can be conveniently transmitted as XDS data in
the barker channel. The configuration information may, for example, be
transmitted as XDS data having a selected type (for example 05h) in the
undefined class. The configuration information is preferably repeated over
and over again, a typical amount of configuration information can be
repeated approximately once every 10 seconds or so over an XDS channel.
In the remotely configurable embodiment, apparatus 20 can be
configured by tuning to the channel containing configuration information
and initiating the configuration process (by, for example, selecting a menu
option or pushing a control button). An unskilled user can therefore easily
initiate a process for reconfiguring apparatus 20 to accommodate changes
to the informational scheme in the user's area or to accommodate a
different informational scheme which is used in a new area to which the
user moves.
2179474
-32-
The configuration information received by apparatus 20 may
describe all of the categories and labels in the informational scheme being
used. In the alternative, to minimize the amount of configuration
information which is required, the configuration information may specify
only additions to a basic informational scheme, such as the scheme
specified by EIA-608.
The apparatus and methods described herein assume some
knowledge about how any additional category information and/or label
1o information will be encoded. For example, if category information is
encoded and embedded in an XDS data packet, as described above, then
new categories may be added simply by adding new characters (up to the
maximum number of characters allowed in a data packet which is
currently 32 characters) to the XDS data packet. The configuration
information could include information about how additional information
will be encoded and/or embedded. For example, configuration information
could include a data type character which is used to identify additional
category and/or label information in data packets sent in the "Undefined"
class specified by EIA-608.
Confi,gu_ration Example
In this example, category and label information is transmitted
in a single XDS data packet. Category information for a number of
categories is transmitted first (with information about two categories
transmitted in each 7-bit character as described above) followed by label
information (with one character specifying a label). The characters used to
specify label information are in the range 20h to 3Fh. The character 20h
2179474
-33-
specifies the first label, the character 21h specifies the second label, and
so
on. An XDS data packet can contain up to 32 characters so, if 4 characters
are used to transmit category information, then 28 characters are available
for transmitting label information.
Apparatus 20 receives configuration information which
specifies, inter alia, the number of characters in the data packet that
contain
category information and the number of characters that contain label
information.
Configuration information may be transmitted in the XDS
undefined class (start character ODh) in type 05h (type character 05h). The
first character following the start character and the type character indicates
whether the data which follows is the name of a category or the name of a
group of labels. For example, the character 7Eh could indicate a category
name and the character 7Fh could indicate the name for a group of labels.
In this example, the rating scheme includes: 4 categories of category
information - rating, violence, sexuality and language - each having levels
described as in Table II, and a group of eight labels or "keywords' for
describing program content -Action, Sexuality, Mild Action, Language,
Family, Mature Content, Graphic Violence, and Nudity.
In this example, the informational scheme includes both
category information and label information. Configuration information
about the categories in the scheme is sent first, followed by configuration
information about the labels in the scheme. Apparatus 20 can locate the
beginning of the configuration information by looking for the first 7Eh
2179474
-34-
identifier to follow a 7Fh identifier. The configuration information may, for
example, be transmitted as follows:
ODh 05h 7Eh R A T 1 N G OFh + Checksum
ODh 05h E X E M P T OFh + Checksum
ODh 05h G E N E R A L OFh + Checksum
ODh 05h P G OFh + Checksum
ODh 05h A D U L T OFh + Checksum
ODh05hRESTRICTEDOFh+Checksum
1o ODh 05h 7Eh V I O L E N C E OFh + Checksum
ODh 05h N 0 N E OFh + Checksum
ODh 05h C O M E D I C OFh + Checksum
ODh 05h M 1 L D 0Fh + Checksum
ODh 05h B R I E F OFh + Checksum
a5 ODh 05h S T R O N G 0Fh + Checksum
ODh 05h G R A P H I C OFh + Checksum
0Dh 05h 7Eh L A N G U A G E OFh + Checksum
ODh 05h N O N E OFh + Checksum
zo ODh 05h E X P L I C I T OFh + Checksum
ODh 05h 7Eh S E X U A L I T Y OFh + Checksum
ODh 05h N O N E OFh + Checksum
ODh 05h E X P L I C I T OFh + Checksum
z5 ODh 05h 7Fh L A B E L S OFh + Checksum
ODh 05h A C T I O N OFh + Checksum
ODh 05h S E X U A L I T Y OFh + Checksum
ODh 05h N U D I T Y OFh + Checksum
2179474
-35-
As each category name is received, microprocessor 42 stores
the category name in memory means 58. Microprocessor 42 then stores the
names of the levels in that category in memory means 58. Microprocessor
42 counts the number of categories and the number of levels in each
category and stores these numbers in memory means 58. When
microprocessor 42 detects the identifier 7Fh then it stores the information
in that packet as a label group name. If there are no labels in the
informational scheme then the label group name can be set to a value such
as NULL (OOh) to indicate that there are no labels. Microprocessor receives
and stores the names for the labels. In this example, the first label name
corresponds to character 20h, the second Label name corresponds to the
character 21h, the third Label name corresponds to the character 22h, and
so on.
In the example there are 4 categories and 8 labels. This means
that the first 2 characters in a data packet containing this information
specify category information. Up to eight more characters may specify label
information.
When the configuration process is started and microprocessor
42 detects configuration information then microprocessor 42 stores the
configuration information in non-volatile memory 58. This is illustrated by
the following pseudo code:
2179474
- 36 -
Configuration
Function parse(configuration, classification);
begin
* Configuration format
N cat=I; 'initialize N-cat, the number of categories to 1
get(char, configuration);
char=7E ~ 'category names are prefaced by, e.g. 7Eh
begin
get(cat name(N_cat), configuration); 'get name of first category
1o i=0 'get descriptive names for category levels
get(level_name(N cat,i), configuration);
level_name(N cat,i) * null ,fig
begin
i=i+1;
get(level_name(N_cat,i), configuration);
end;
N_Ievel(N cat) = i; 'store number of Ievels in this category
N_cat=N cat+1;
end;
2o j~ char=7F ~g 'descriptive labels are prefaced by e.g. 7Fh
begin
get(label_name, configuration);
i=0;
get(label(i), configuration);
label(i) * null ~
begin
i=i+Z;
get(label(i), configuration);
2179474
-37-
end;
N level(N cat)=iy
N cat=N cat-1; 'Store total number of categories
end;
* Parse Classification Data
~ i=1 to N cat,~g get(cat(i), classification);
get(char, classification);
i=I;
3xhile char null ~
1o begin
label(i)=get(char, classification);
i=i+1;
get(char, classification);
end;
The architecture of apparatus 20 which is described above
permits an easy to use user interface. In the currently preferred
embodiment of the invention the user interface includes an infrared
2o receiver 70 and an on screen display generator 60 both connected to
microprocessor 42. The user can set the user preferences stored in
apparatus 20 by malting selections with an infrared remote control
transmitter 71 (Fig 4) and confirming the changes by viewing the display
generated by on screen display generator 60 on the screen of television 22
(or some other display connected to microprocessor 42).
2 i X94.74
~,
-38-
Much of the data encoded and embedded in incoming video
signal24 is of interest to viewers. For example, a viewer may be interested
in knowing the title of the current television program, how long the current
program has left to run etc. Preferably infrared remote control transmitter
71 includes a key 75 which, for a short period, for example, a few seconds,
displays the title of the current program together with other information
about the current program. This information is stored in RAM 46 in
apparatus 20. It is therefore trivial to cause microprocessor 42 to send this
information through on screen display driver 60 for display on the screen
of television 22 as shown, for example, in Figure 6.
Preferably the system of menus in the user interface is no more
than 3 levels deep and permits access to the most often used functions of
apparatus 20 with a minimum number of key strokes. The techniques for
setting user preferences by means of an infrared remote control are well
known and are widely used, for example, in programming VCRs. These
well know techniques are therefore not described here in detail.
In the currently preferred user interface a user can invoke a
2o main menu 80 by pressing a function key 72 on remote control transmitter
71. When the function key is pressed, microprocessor 42 switches
switching means 38 OFF and causes on screen display 60 to display a
request that the user enter an access code (or "PIN"). Microprocessor 42
verifies that a valid PIN has been entered. When a valid PIN has been
entered then main menu 80, as shown in Figure 5A, is displayed on the
screen of television 22. If a valid PII~ is not entered then microprocessor 42
does not permit access to main menu 80.
21194?4
-39-
Main menu 80 provides a user with several options [1]
through (6]. The user can select one of these options by pressing the
correspondingly numbered one of buttons 88 on infrared remote control
transmitter 71. Each selection either sets an operating parameter of
apparatus 20 or opens a further menu which may have selections leading
to other menus.
The "Blocking" option [1] on menu 80 allows a user to enable,
temporarily disable for a selected period of time (or "put to sleep"), or
1o disable completely the blocking function of apparatus 20. The "Blocking"
option would be used, for example, by parents who wish to have ux~liniited
access to all television programming without altering other settings of
apparatus 20.
Option [1] could optionally open a menu 90 (Fig 5B) which
allows the features of apparatus 20 to be individualy enabled or disabled.
Each of the features listed beside options [1] to [6] of menu 90 can be set to
ON, SLEEP (for a specified time period) or OFF by pressing the
correspondingly numbered one of buttons 88 on remote control transmitter
2o 71 until the desired setting is obtained. If ON is selected, the feature is
enabled and will operate according to the manner in which it is configured.
If SLEEP is selected the feature will be disabled for a period of time
designated by the "Sleep Time". If the user selects OFF the feature will be
disabled and will not operate.
as
The "Master" option [1] of menu 90 can be used to disable or
temporarily disable the operation of all blocking features of apparatus 20.
2179474
- 40 -
In the alternative, a user may simply disable one or more individual
features from the list of menu choices which includes: "Ratings Block",
"Channel Block", "Program Block", "Viewing Times", and "Daily
Allowance" features. In the example menu 90 of Figure 5B the operation of
"Channel Block" has been suspended for one hour. Any channel may be
viewed although the incoming video signal 24 may still be blocked by an
enabled feature of apparatus 20. No restrictions are placed on specific
programs or viewing times because those features are OFF.
1o The set up function, option [2] of menu 80 opens a menu 100
(Fig. 5C). Menu 100 lists various parameters that a user can set to affect the
operation of apparatus 20. The values that the user selects for these
parameters comprise preference information which is stored in memory
locations 56 in non-volatile memory 58 and used, as described above, to
determine whether or not a received video signal 24 will be blocked by
apparatus 20. For example, when a user selects "Category Thresholds'
from menu 100, the user is presented with another menu 110 (Fig 5D).
Menu 110 allows the user to set thresholds in the various categories in the
informational scheme for which apparatus 20 is configured by, for
2o example, pressing a button on remote control transmitter 71 to cycle
through the available levels. The categories correspond to embedded codes
containing category information that might be present in incoming video
signal 24.
The user is assisted in setting threshold levels because menu
110 displays the descriptive names for the categories, as indicated by 111,
as well as the descriptive names 112 for each level in each category. These
CA 02179474 2000-02-21
-41 -
descriptive names are part of the configuration information according to
which apparatus 20 is preferably configured. If apparatus 20 is reconfigured
for use with a different rating scheme then menu 110 will display category
names and category level descriptions according to the new rating scheme.
After a user has selected thresholds for each category, the
currently set threshold level for each category is stored as preference
information in non-volatile memory 58. This can be done, for example,
when the user exits menu 110. Apparatus 20 will block incoming video
signal 24 whenever incoming video signal 24 has an embedded code
containing category information identifying a level in a category which
equals or exceeds the value of the threshold level for that category (which
is stored a memory location 56 for that category in non-volatile memory
58). It can be readily appreciated that apparatus 20 can simultaneously
accommodate multiple categories and can be set to block an incoming
signal 24 that meets or exceeds a threshold level set for any one category.
In accordance with the present invention, the ability to
simultaneously handle multiple rating schemes, as broadcast in real time,
is useful because of the many sources of television programming.
Television programming which originates in Canada from a Canadian
broadcaster may be rated according to a first rating scheme. Television
programming which originates in the United States from a United States
broadcaster may be rated according to a second rating scheme. Both sets of
television programming may be received by a person located anywhere in
North America. It is therefore desirable that a video blocking system
can seamlessly accommodate television programming which includes
2179474
embedded codes containing information relevant to either or both rating
schemes. Additional informational schemes set up by, For example, groups
of concerned parents could also be handled by apparatus 20.
Options [2] and [3] of menu 100 allow a user to select labels
which, if present in an incoming signal, will cause apparatus 20 to block
the signal. Option [2] allows a user to specify labels in a group of labels
specified by the rating scheme being used. Option [3] allows the user to
specify labels from the list of types set out in EIA-608. When restricted
1 o labels (option [2]) is selected, a display of various labels that are
provided
by the informational scheme according to which apparatus 20 has been
configured is displayed on television 22 (Fig. 5E). Apparatus 20 can be pre-
configured with the various types specified by EIA-608 (Fig. 5F) because
these types do not change.
The number of different labels that can be used as criteria to
determine whether or not to block video signal 24 is limited in practice
only by the amount of memory in apparatus 20. One program may
simultaneously have several "labels" associated with it by broadcaster 26.
2o For example, a cartoon about a gruesome mass murderer might have the
following labels which describe the type of program in video signal 24:
"ANIMATED", "HORROR", "CRIME", and "DRAMA". Other labels
describing the program could optionally be embedded in video signal 24
and encoded in an ADVISORY group of labels. For example, a broadcaster
could assign key phrases, such as "rape scene', "strong action violence',
"strong sexuality", "gory violence", or "brief partial nudity', where
appropriate, to a television program. The labels are descriptive and are
2179414
-43-
therefore relatively easy for a user to understand when the user is deciding
what labels should cause apparatus 20 to block a video signal 24. The text
of the labels is downloaded to apparatus 20 and stored when apparatus 20
is configured as described above.
The "Viewing Times", option (4J of menu 100, permits a user
to allow TV viewing only during certain hours of the day. When a user
selects option j4~ of menu 100 then a menu 160 (Fig 5I) is displayed. By
setting the options on this menu, a user can store viewing time information
1o which specifies time ranges during which television viewing is allowed. At
all other times incoming signal 24 will be blocked by apparatus 20. Of
course, the viewing time information could specify time ranges during
which television viewing is not allowed. Preferably, appropriate viewing
tune ranges can be set separately for morning, afternoon and evening.
Apparatus 20 preferably reads and decodes embedded codes
containing "Time of Day" information (or "time data") which contain
information about the time at which video signal 24 is being transmitted
by broadcaster 26. Microprocessor 42 then compares the decoded time data
2o with the stored viewing time information. If the result of the comparison
indicates that the time data corresponds to a time within an allowed
viewing time range then microprocessor 42 operates switching means 36,
38 to allow video signal 24 to be displayed on the screen of television 22.
If the result of the comparison indicates that the time data corresponds to
a time within a non-allowed viewing time range then microprocessor 42
operates switching means 36, 38 to prevent video signal 24 from being
displayed on the screen of television 22.
2179474
Because time of day information is contained in incoming
video signal 24 the operation of apparatus 20 does not depend on a local
clock being accurately set. Further, the operation of apparatus 20 cannot be
thwarted by resetting a clock in apparatus 20. Apparatus 20 may include
a back-up real time clock for cases in which the incoming video signal does
not contain time data.
A user can set the morning start time from 3:00 AM to 11:30
AM in 1/2 hour increments by displaying menu 160 and pressing the [1]
1o key on remote control 71. The duration for morning viewing is adjustable
from 0.5 hours to 9.0 hours in 1/2 hour increments by pressing the [2] key.
The user can set the afternoon start time from 12:00 PM to 5:30 PM in 1/2
hour increments by pressing the [3] key. Similarly the duration for
afternoon viewing is adjustable from 0.5 hours to 6.0 hours in 1/2 hour
increments by pressing the [41 key. Finally, the user can set the evening
start time from 6.00 PM to 2:30 AM in 1/2 hour increments by pressing the
[5] key. Similarly the duration for evening viewing is adjustable from 0.5
hours to 9.0 hours in 1/2 hour increments by pressing the [6] key.
"Daily Allowance", option [5] of menu 100, lets a user set a
ma~dmum amount of time that signals to television 22 are not blocked by
apparatus 20, in increments of 0.5 hours. The Daily Allowance can be set
by displaying menu 100 and repeatedly pressing the [5] key on remote
control 71 until the desired daily allowance is displayed.
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The Unrated Programs option [fi] of menu 100 determines
whether programs which are not accompanied by embedded information
will be blocked by apparatus 20.
"Display Blocked Stations", option [4] of menu 80, allows a
user to view a list of stations (Fig. 5G) which will be blocked by apparatus
20. A user can add a station to the list of prohibited stations by tuning to
the undesired station, pressing button 75 on remote control 71 to display
information about the station (it may take a few seconds for the data packet
containing the call letters to be received) and selecting [2] on the remote
control. When this is done, the call letters of the station are added to a
list
of blocked stations stored in non-volatile memory means 58.
Stations on the list of Figure 5G may be deleted by pressing
the correspondingly numbered key on remote control 71. If there are more
than 8 channels in the list the user may press [8] to view and/or modify a
list of additional channels. Apparatus 20 can store a large number of station
call letters. The list length is limited in practise only by the available non-
volatile memory 58 accessible to apparatus 20.
Apparatus 20 could be configured to allow a user to type in
directly a list of stations or program titles to be blocked. However, reading
the call letters of stations to be blocked and the titles of programs to be
blocked directly from data packets in the incoming signals ensures that the
blocking information in apparatus 20 will exactly match the information
embedded in incoming video signal 24.
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"Display Blocked Titles", option [4] of menu 80, allows a user
to set up a list 150 of programs (Fig. 5H) which will be blocked by
apparatus 20. A user can set up and maintain a list of prohibited programs
in essentially the same manner as the user sets up a list of blocked stations.
The length of list 150 is limited in practice only by the available amount of
non-volatile memory in apparatus 20 available for storing list 150.
The Captions option [5] of menu 80 allows a user to select one
of 9 captioning modes. The user may choose to display the information
being transmitted in one of the close caption channels CC1 to CC4,
information transmitted in one of the text channels T1 through T4 or no
caption information. Where data packets representing encoded information
for use by apparatus 20 are transmitted in, for example, text channel T2,
then apparatus 20 strips out the characters which comprise the data packets
before displaying text channel T2.
The Change PIN option [6] of menu 80 allows a user to select
a new PIN for access to apparatus 20.
2o The user interface may be implemented by causing
microprocessor 42 to run software which operates generally according to
the following pseudo code:
Istfra-red (IR) Data Receive and On-Screen Display Algorithm
)I~-begin;
get(data,key)
key = key 75
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begin
display(Tnformation)
get (data,selection)
if selection=1 ~ update (title_list)
j~ selection=2 th_lle update (station_list)
end;
'require user to enter PIN before allowing user to set preferences
j,~ key = key 73 ~ get(string, PIN);
if PIN=User_PIN
1o begin
display(Main);
'allow user to pick item from main menu
get(data, menu selection);
*BIocking
jf menu_selection=1 change(ViewControl block, +1);
*SetUp
menu_selection=2
begin
display(ViewControl_SetLJp);
get(data,menu selection);
*Category Thresholds
i# menu selection=1 lh~
begin
display(cat name(N cat),label_name,Category_Thresholds):
get(data,menu selection);
jf menu selectionc5 ~ change(cat setting(menu_selection),
+1);
i~ menu selection=M exit;
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end;
*Restricted Labels
if menu selection=2 ~
begin
display(label(N_level(N cat)), Restricted_Labels);
get(data,menu_selection);
j~ menu selection<9 toggle(label(menu selection));
if menu_selection=M 111eu exit;
end;
*Restricted Types
,menu selection=3,~
begin
display(Restricted_Types);
get(data, menu selection);
j~ menu_selection <9 toggle(type(menu_selection));
if menu selection=M exit;
end;
*Viewing Times
if menu selection=4,~g~
begin
display(Viewing_Times);
get(data, menu_selection);
if menu_selection=1 ~ change(Morning_Start, +30);
menu_selection=2.t~n change(Morning_Duration, +0.5);
~ menu_selection=3 the change(Aftemoon_Start, +30);
if menu selection=4 lh~ change(Aftemoon Duration, +0.5);
if menu selection=5 ,t~g~ change(Evening_Start, +30);
f menu selection=6 ~n change(Evening_Duration, +0.5);
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j~ menu selection=7 ~ change(Time Zone, +60);
change(clock, Time_Zone);
if menu selection=M ~ exit;
update(viewing_times);
end;
*Daily Allowance
iF menu_selection=5 ~g change(Allowance, +0.5);
*Unrated Programs
i~' menu selection=6 Toggle(Unrated);
*Configure
if menu selection=7 ~ Toggle(Configure Enable);
end;
*Display Blocked Titles
i~ menu selection=3 ~
begin
display(Program_Blocking_list);
get(data, menu selection);
if menu selection <8 ~, toggle(program(menu_selection));
j~ menu_selection=M ,~ exit:
end;
*Display Blocked Stations
if menu selection=4 ~
begin
display(Channel_Blocking_List);
get(data, menu selection);
jf menu selection <8 remove(channel(menu_selection));
y~ menu selection--M ,~ exit;
end;
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*Captions
j~ menu selection=5 toggle(Captions, +1);
*Change PIN
if menu selection=6 the
begin
display(Enter Old PIN);
get(string, PIN);
i~ PIN=User_PIN ~e
begin
1 o display(Enter_New_PIN);
get(User PIN);
end;
end;
*Exit Menu
jf menu selection=M ~ exit;
end;
1TZ_end;
It can be appreciated that the methods and apparatus of the
invention provide parents with a great deal of flexibility in blocking
programming which they consider to be undesirable. In addition to
blocking programs which exceed set thresholds in categories in one or
more rating schemes or which include Labels selected from one or more
groups of labels, parents can:
~ block out specific channels (at specific times, if desired);
block out programs of a specific title, for example, parents can block
their children from watching a program having the name "The X
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Files' at any time, regardless of the ratings assigned to any specific
episode of that program;
~ block programs which contain labels identifying them as being of
particular types, for example, parents could set apparatus 20 to block
programs of one or more of the following types: combat, crime,
erotica, fantasy, horror, soap opera, suspense, tallc, etc.;
block access to all programming at certain times of day. Parents can
also Iimit viewing time to a set amount of time per day.
1o All of the above functions are available to parents in a consistent way.
Those skilled in the art will realize that the foregoing description of a user
interface can be varied in many ways without departing from the scope of
the invention. 'The user interface need not use a remote control n but could
use any known means for accepting input from a user. The user interface
need not display information on the screen of television 22 but may use
some alternative display means to advise a user about the status of
apparatus 20. Apparatus 20 need not include all of the features described
above and may include additional features. The menu structure described
above may be departed from while staying within the scope of the
invention.
As will be apparent to those skilled in the art in the light of the
foregoing disclosure, many alterations and modifications are possible in
the practice of this invention without departing from the spirit or scope
thereof.
s
