KR19990077223A - Method and apparatus for suppressing television program display in accordance with content - Google Patents

Abstract

Methods of controlling the viewing of television programs in accordance with the contents of the program include providing codes using ancillary data channels that represent sexual content, violence, disastrous content, and the like. These codes are assembled into a teletext signal and detected at the receiver. The receiver is programmed by entering a corresponding code indicative of acceptable or forbidden content, causing the display to be erased and allowing the voice to be silenced according to the transmitted code. Systems, program sources and receivers are also described.

Description

Method and apparatus for suppressing television program display in accordance with content

The present invention relates to a method and apparatus capable of suppressing television program display in accordance with program contents.

In the United States, a television receiver having a display of a predetermined size or larger, which has been commercially available since 1998, passed a bill stating that parents should have a means to prevent children from seeing a coded program containing violence, sex and profanity. A so-called < RTI ID = 0.0 > so-called < / RTI > < RTI ID = 0.0 > term " V-chip " has been proposed.

In the United States V-chip system, the broadcasting facility grades each program with four categories of censorship. At this time, the values for each category are simultaneously transmitted as part of the Extended Data Services (EDS) of the Closed Captioning (CC) system. This value is transmitted as long as the program is on air.

Using the access control mechanism, the parents set thresholds for each category. If the rating exceeds a previously allowed value, the V-chip suppresses video and audio signals. Since the response of the V-chip decoder is almost instantaneous, the system can easily handle channel hopping. Parents also do not have to worry about whether the warning will be missed at the beginning of the TV guide or program.

The Electronic Industries Alliance (EIA) specifies four censoring categories and the number of data bits required to transmit the code.

- MPAA rating (equivalent to film rating, eg 18, PG, etc.) - 3 bits

- Violence content recommendation level - 2 bits (allows a ratio of 0 to 3)

- sexual content recommendation level - 2 bits

- Adult (mature) content Recommendation level - 2 bits

The same principle applies to systems actually tested in Canada, but at present the two systems are not identical.

All US television sets assembled after July 1993 should include a CC decoder to provide subtitles. A SAA5252 decoder available from current CC decoders (Philips Semiconductors) can clear the TV picture when switching to full-text mode. Also, since they have display characteristics suitable for generating an OSD menu, parents can program the screening threshold.

Unlike teletext, CC data can be recorded and played back by a VHS VCR during program playback. In addition, the recorded and reproduced tapes may contain censored data.

In Europe, the issue of implementing a V-chip system is generally more complex than North America. Broadcasting facilities are not coordinated by a single government because there are differences in acceptable ethical standards and differences in culture and language. Thus, there is a technology to cope with a 625 line TV system having a small reserve capacity for redundant data signals.

The obvious solution is for use in US systems, but it has some disadvantages.

First, in broadcast facilities, the CC signal can occupy valuable teletext transmission capacity (one line is permanently lost), and a different encoding system may be required.

Second, the transmission equipment and the data bridge (cable amplifier) for the teletext signal and the CC signal are required in duplicate, which is costly.

Third, consumer electronics manufacturers incur additional costs because they provide teletext and CC decoding for each TV set and PC TV card.

The concept that parents can control the viewing of television sets using information transmitted by broadcast facilities is not new and is presented in WO83 / 02208, published June 23, 1983. According to this document, a code formed as a selected row number of a predetermined teletext page is transmitted through a teletext signal transmitted as a television signal. Therefore, the page number and the row number are transmitted in a field erase period which is required for occurrence of an unpleasant event. At the receiver, the teletext decoder is permanently set to find the relevant page and recognize the line number upon transmission. A particular row number represents a specific class of voice and video events.

The apparatus includes a telexter decoder, but a viewer who has a device that does not include means for suppressing display in response to a row address transmitted to a predetermined page may watch the program contents or may not watch it The contents of the program can not be determined.

UK Patent Application No. 9619878.3 (PHB 34110) discloses another proposal for controlling access to the viewing of a television program, wherein the program rating code is transmitted in packet 8/30 format 1 data. The packet is independent of the page transmission and is transmitted at intervals of about one second so that the rating code is quickly updated to suppress short phrases that may, for example, include unwanted visual or auditory data . Since the teletext packet does not contain displayable data, the user can not easily obtain information about the contents of the program currently being transmitted without the control system.

1 shows a television system for achieving a method according to the invention;

2 is a block diagram schematically illustrating a television program source according to the present invention;

3 is a schematic diagram illustrating a code word that is categorized in a program and inserted into a teletext extension packet;

4 is a block diagram schematically showing a television receiver according to the present invention.

5 is a view showing a processing step for programming a television receiver to operate in accordance with the method of the present invention.

6 illustrates an on-screen display message that may be presented by way of example of the method of the present invention, by way of example;

Figures 7A and 7B show a display screen in which both a displayable rating code and machine readable code are included in the display page.

DESCRIPTION OF THE REFERENCE NUMERALS

1. Television signal source 2. Television transmission medium

11. Teletext inserter 12. Transmission network

14. Teletext editing system 15. TV access control equipment

An object of the present invention is to enable an editing function by a parent or others authorized by the receiver of the output of the television receiver.

The present invention provides a method by which authorized persons can disable the audio and / or video display of a television program or a portion thereof according to program content,

I) a step of determining the rating of the entire and / or momentary content of the television program,

Ii) generating a code word indicative of an assigned class status;

Iii) inserting the code word in a machine readable form and a displayable form into a teletext signal multiplexed with a television signal representing the program

.

By providing the rating code word in the machine readable and displayable form as described above, the teletext decoder is provided with an automatic means that has a code set by the user and compares the code with the transmitted code, The viewer having the receiver can use the rating of the program. Therefore, if the automatic means is included in the receiver, the rating code inserted in the displayable portion of the teletext data is automatically operated by the viewer in the case of having the teletext decoder but without automatic means, It is possible to suppress the audio and / or video display on the display screen. Therefore, even when the receiver in use does not have a function of automatically suppressing the display, the user can call the program rating page to check the rating of the program currently being transmitted.

Since there is already an infrastructure for inserting teletext signals in the transmitted signals in various countries and many teletext receivers now include teletext decoders, it is advantageous to use teletext transmission to transmit the codes Do. Therefore, the viewer's request for the teletext service and editing facility can be added relatively easily to the receiver and the program creation source.

Thus, in order to enable disabling of the audio and / or visual display, the program providing side inspects the contents of the program and makes appropriate markings on the contents of the program using the code embedded in the associated teletext signal. The person adjusting the television set can then use this code to determine whether the program is to be displayed (visible and / or verbally). Using a teletext packet to transmit a code can generate a visual indication of the code and, if automatic means are provided, enable automatic display suppression and, if a receiver with only basic teletext decoder is used, Only the visual display of the < / RTI >

The teletext pages are transmitted in order, and as a result, a given page may be given priority. Thus, the repetition rate can be matched to the rating of the content. That is, if there is a high-grade code, the page can be transmitted more frequently. As a result, the grade can often be easily changed if desired. Thus, the frequent occurrence of unpleasant events can be edited and removed during viewing of the program as a whole. For example, news and current event programs may, as a relatively short portion of the program, include miserable or uncomfortable scenes, such as events that flow out of a war zone. The packet may also be transmitted more frequently, allowing shorter events such as a word to be deleted.

The displayable code can be displayed at a predetermined position on the teletext page, and the machine readable code is a code for generating the displayable code at a predetermined position.

This has the advantage that only one set of codes is transmitted that provides displayable information. This is accomplished by assigning multiple specific locations on the page to display information related to the rating of the program. In this way, the data received at the receiver can be analyzed, and the code at the location assigned on the display page is known to define the program rating. Thus, the control circuit can use the information to suppress the display of the program if the code detected at the location allocated on the page surpasses the code set stored by the user.

In another method, the displayable code can be freely positioned on the teletext page, and the machine readable code is at a predetermined position on the page.

This has the advantage that the creator of the page is free to edit more. That is, the displayable code does not limit the layout of the displayed page, and the rating code has to be transmitted twice, in order to generate code that can be read by the machine for display of information once. Separating the two functions can provide greater flexibility in page layout, for example, on a single line, such as one line, which is often left blank in the broadcast station to separate the title of the page from the information on the page Machine readable code can be located.

The machine readable code may be erased from the display. In this way, if a line is used, there will be an unmarked line between the page heading and the text on the display page.

In another embodiment, the machine readable code may be included in an extension packet associated with the displayed page.

In this case, not only all the benefits described in the pending UK Patent Application No. 9619878.3 (PHB 34110), but also the additional advantages given by transmitting a displayable rating code.

The machine readable code may be protected by an error correction code. Using the above method, if the displayed code and the machine readable code are the same, the codes can be protected only by the parity check. The current teletext decoder automatically performs parity checking on all received characters in the page. However, if the machine readable code is hidden from the display, it can provide a larger error protection class for such code. For example, as disclosed in UK Patent Application No. 9619878.3 (PHB 34110), the machine readable code in the extension packet may be a Hamming code, although it is not displayed. Similarly, if the machine readable code is hidden in a given row of pages, it can receive a larger error protection rating than the displayed code without disrupting the viewer.

Current teletext decoders, especially simpler decoders, only perform a parity check on each character, and if the characters have different error protection codes, then the indicated characters will not be the same as the encoded transmission character. Therefore, when these characters are displayed, they have no meaning or will confuse viewers.

The rating code is inserted into the current program page containing displayable information associated with the program currently being transmitted.

The page is transmitted on a predetermined page number, and the page number can be transmitted to the nonvolatile memory of the receiver and can be accessed by pressing one button of the remote control device.

If the rating code changes, the transmission frequency of the current program page may increase.

Since the teletext pages are transmitted sequentially, different priorities can be assigned to different pages, and thus a particular page can be transmitted at a frequency determined by the broadcast station. Therefore, the broadcasting station can change the transmission frequency according to the contents of the page. As a result, if a change in rating occurs, a high priority is assigned to the transmission of the page, so that the delay in transmitting the page is minimized. The device can be used to make short phrases or even individual words inhibitable.

The transmission frequency of the current program page may increase as the grade level increases.

The time taken to access the page decreases as the transmission frequency increases. That is, the pages are transmitted in shorter time intervals. Thus, when a viewer requests a page, the time it takes will appear to be less than or equal to the interval between successive transmissions of the page. Thus, if a higher rating code is sent, the maximum wait time to receive and display the page will be shorter.

The method may include another step of generating an error correcting code for insertion into the packet as a code word. In one embodiment, the codeword is protected by a Hamming code, which is a coded 4/8 Hamming.

Thus, it is possible to securely receive the rating code, and as a result, minimize the possibility of unauthorized or unacceptable display due to errors in the transmission or detection of the rating code word.

More than one rating criterion may each be encoded using a code word comprising two bits, and each criterion may be applied to the entire program or each event in the program. A rating criteria may include one or more of violent content, sexual content, disastrous content, or poor language.

Using 2-bit code words for each criterion, four possible levels can be set for these criteria. For example, taking the criteria for violent behavior, code 00 indicates no violence, code 01 indicates weak violence, code 10 indicates moderate violence, code 11 Indicates a high degree of violent behavior.

One of the codes represents a start region of the program, and the start region can be represented by a 4-bit code.

It is effective to consider different cultures in the indication of the program start area. Thus, it may be desirable to modify the meaning of a particular code or to modify the sense of control over the TV set upon commencement of the program, as unpleasant things in one country or religious group may not be in the other group. Thus, the level may be increased or decreased at the receiver by providing an area of the start code, as some organizations may vary the degree of acceptance for sexual or violent behavior.

In one embodiment according to the method of the present invention, the extension packet containing the codeword may be inserted at the beginning and / or end of the event that changes the rating within the program being classified during the near field cancellation period.

Typically, packet 8/30 format 1 is transmitted approximately once per second. To ensure that individual words are disabled, it is not very accurate, for example, to allow a packet to be sent during a near field cancellation period to make the time to suppress the word sufficiently after 20 msec .

Other words may be provided to replace words that are deemed inappropriate for the selected grade level.

These words may be sent to a channel for a proposed Audetel service that provides an auxiliary channel, e. G., An audio assistance signal for depicting the operational scene.

The invention also provides a method of disabling audio and / or video display of a television program,

Iv) setting a user's authority to define a program to be disabled or a portion thereof,

V) inputting a code word corresponding to the content of the program to be inhibited into a memory in the television receiver,

Vi) receiving a television signal, the television signal being arranged in a teletext signal multiplexed with a television signal, the television signal comprising a displayable codeword indicative of a program rating and a machine readable code word,

(E) comparing the received codeword with the input codeword, and

And (e) disabling the audio and / or video display according to the comparison result.

Using the method of the present invention, for example, it is possible to control the reception of a television signal having inappropriate contents for a child.

Also, by displaying a specific teletext page including a rating code of a form that the viewer can see, the rating applied to the program to be broadcast can be monitored. Thus, the method allows the viewer to view the rating of the program on a standard teletext display page, and if the automatic means is present in the receiver, the program can be automatically disabled.

The machine readable code word is located in the extension packet of the teletext signal. This may be a page-related extension packet, such as packet 26, or a non-page-related extension packet, such as packet 8/30 format 1. A television set or a video recorder equipped with a teletext decoder capable of detecting and decoding an extended packet can be used to check the rating of a program according to the contents of the program, and when a user inputs a requested rating to be suppressed, Means are provided for disabling the output of the set or the recording function of the video recorder.

Step (iv) of the method of the present invention may be accomplished by means of a Personal Identification Number (PIN). Further, step (iv) of the present invention is achieved by checking the physical characteristics of the licensor.

A relatively simple way to set permissions is to issue a PIN that only an authorized user will know. Then, the input PIN is compared with the stored PIN (only the authorized user knows), and if it is determined that the PIN is the same, the rating code may be updated.

A disadvantage of using a PIN is that the user may forget it or be exposed to unauthorized users. Alternatively, you can monitor your physical characteristics, such as fingerprints, voice, facial features, etc., and require more complex equipment.

The codeword can be input using a remote control device.

Remote control devices are often found in television sets and are always present in television sets capable of receiving and displaying teletext data. They have a numeric keypad so they can be used to enter a PIN and have other keys to enter the desired rating code.

An on-screen display message may be generated to aid in the entry of codewords.

By this means, the process of inputting a code associated with a different rating criterion is progressively progressed by a command and a selection which are continuously displayed.

An on-screen display message may be generated informing the viewer why the audio or visual display is disabled.

Such a message will prevent viewers from assuming that the display or set of voices have stopped the television set. The message may be in the form of, for example, a " regulated voice due to a poor language ", or a " display regulated by a disastrous event ".

The regulated voice may be replaced by another voice.

Thus, undesirable words or phrases may be " bleed " or other sounds. This feature tells viewers that there is a control feature that regulates words when they are replaced by mute, without thinking they are malfunctioning.

Other sounds may be determined by the received signal.

Thus, a range of sounds may replace the initial word. For example, the alternative sound may vary depending on the length of the excerpt to be replaced. In another example, another unjust word may be sent on the supplemental channel to replace a word that is not allowed by the selected grade. The other word may be transmitted, for example, using the predetermined redundancy in the proposed Odette service.

The invention also relates to a teletext signal embedding device, means for classifying the television signal to be transmitted in accordance with the program content, means for generating a code word indicative of a rating assigned to the program or portion thereof, And means for inserting a codeword into the teletext signal in a machine-readable form.

Many current television signal sources include teletext inserters, and many service providers include means for encoding extension packets for which the page is not relevant.

The teletext signal may be one specified in the world system teletext standard, and the machine readable codeword may be inserted into the extension packet. The extension packet may be packet 8/30 format 1.

Typically, these extension packets are transmitted at approximately one second intervals, and are not related pages. It is also decoded by a number of teletext decoders and includes information about the program provider, the first page to be captured, and the real time clock. Four bytes in this packet used in accordance with the present invention are used to transmit the program rating code.

Means may be included to change the rating during the duration of a single program.

In this way, the rating code can be used in two modes. The first mode is to prevent reception of the entire program which is deemed unacceptable, and the second mode is to allow viewing of the program but to eliminate possible unpleasant events. The length of the event that can be removed depends on the transmission frequency of the code. Packet 8/30 format 1 is typically transmitted once per second, and events can be easily deleted in a number of second modes. It is also possible to transmit additional packets 8/30, so that the timing for the near field cancellation period can be obtained.

Means for correcting an error in a codeword may be provided. The word can be protected by a Hamming code. The codeword can be coded 4/8 decoding.

By protecting the errors of the codeword, the possibility of erroneously suppressing or displaying events in the program or program due to transmission errors is reduced.

A codeword may include one or more of the following categories: words that determine the level of sexual content, violence, nasty language, and horrible images or voices.

These categories can be applied to voice or video and can be applied to individual events within an entire program or program. For example, a new program can describe a high level of violence during special reporting, such as in a war zone. In addition, these may include disastrous contents, for example, a screen of the underage according to starvation. Another example of content that may appear disastrous to certain viewers is a surgical display of a medical program.

In addition, the codeword may include a codeword indicative of a starting region of the program.

Different areas and countries have different customs, so content that can be accepted in one area may not be the same in other areas. Therefore, low level violence in one area can be considered as medium or high level violence in another area.

The invention also provides a recording medium comprising data representing a television program, a rating code word indicative of a rating assigned to the full and / or momentary content of the program, and an associated teletext signal, And is included in a displayable or machine-readable form in the teletext signal.

This can categorize and regenerate the playback of recorded media such as videotape or optical disc that can be purchased by a person who does not want to let the authorized person view it. That is, the parent may consider that it is inappropriate for the child to choose the video. When the recording medium is classified in the same manner as the broadcast content, the same control can be executed while watching.

The teletext signal may conform to the world system teletext standard, and the machine readable codeword may be inserted into the extension packet. The extension packet is 8/30 format.

The teletext signal may be converted to a multilevel code to reduce the bit frequency of the teletext signal, in which case the recording medium may be a VHS video tape.

As is widely known, it is customary that teletext signals can not be actually recorded and reproduced using a VHS video recorder due to bandwidth limitations. Several proposals have been made to overcome this problem, one of which is disclosed in EP-A-0608960 (PHB 33932). In this application, one line of teletext data spans five lines of the field erase period. As a result, not all teletext data can be stored, and the selection of such data is necessary at the time of recording.

One use for such a device is the caption recording for deaf, which is typically sent on page 888. In addition, the rating codes may be recorded in the same manner, but other teletext information that need to be recorded may be limited.

Another proposal for recording teletext data on VHS tapes is described in British Patent Application No. 9605614.8 (PHB34056). In this proposal, the teletext signal is converted from a low frequency to a multilevel code. This allows the VHS recorder to be used to store and play back all transmitted teletext data, so that the rating code in the extension packet can be stored on the tape.

The present invention also provides a television receiver suitable for receiving and displaying television signals from such a television signal source or recording medium, said television receiver comprising a teletext decoder, a machine readable by the machine representing the rating assigned to the locally received program Means for displaying the displayable rating code, means for inputting information indicative of a predetermined program rating indicating a program for which display suppression is desired, comparing input and received ratings, And means for allowing or disallowing display according to the result of the comparison.

Therefore, a code corresponding to a program or a part of the program for which suppression is desired is input into the television receiver. The corresponding code is received via the teletext signal and can be compared with the incoming code to control the display and audio output of the receiver within the receiver. If the code is included in a teletext extension packet rather than an associated page such as packet 8/30 format 1, then it is not necessary to have a teletext decoder to permanently look for a particular page. Instead, the teletext decoder may perform a normal function of obtaining a user selection page, and may automatically acquire an unrelated page extension packet.

The authorization means may be provided so that only authorized persons enter the program rating.

The authorization means may comprise means for inputting a PIN, means for comparing the entered PIN with the stored PIN, and means for allowing entry of the program code if the stored and input PIN is the same.

This provides an easy secure means to allow only authorized persons, for example, parents, to change the rating code. However, the code has the disadvantage that it can be forgotten or damaged. In the first case, it is difficult to change the rating, and in the second case the unauthorized person can change the rating.

Alternatively, the authorization means may comprise means for monitoring the physical characteristics of the licensor, means for storing the inspected features, means for requesting a change in the acceptable program content, means for monitoring the features in response to the request, Means for comparing stored features, and means for altering acceptable program content as a result of a correction comparison.

Several physical features, such as fingerprints and facial features, are available.

The fingerprint detector is used for credit card verification of the store terminal. Means for recognizing facial features are described in EP-A-0 551 941 (PHB 33765).

The advantage of using physical features is that it is difficult to tamper with, and there is no need to remember PINs or other external data.

Means may be provided for generating a message on the screen display to inform the viewer of why the audio and / or display is disabled.

This prevents the viewer from guessing that the receiver has failed when the program can not be received or received due to rating.

Means for replacing an inappropriate word with another audio signal may be provided. The other audio signal may represent another non-rejected word. The other word may be received as part of a television signal.

Thus, if an objection word occurs, they can be replaced by, for example, a blip signal. Alternatively, they may be replaced by other unintelligible words. One way to achieve this is to use a supplemental channel in which the program generator transmits a selective word. Auxiliary channels that may be used are the Odette channels proposed to transmit occluded or partially observed audio aids messages.

Means for disabling audio and video display may be provided if the rating code is not received at all by the television signal.

This can regulate playback of unclassified programs. This is either because of their lifetime or because they arise from illegal sources such as video tapes. In particular, highly controversial tapes can be generated without corresponding rating codes.

These and other features and advantages of the present invention can be seen in the following description in accordance with embodiments of the present invention with reference to the accompanying drawings.

Figure 1 is a schematic block diagram of a system in which the method according to the invention can be achieved. The system shown in Fig. 1 includes a television signal source 1, a television transmission medium 2, and a plurality of television receivers 3-1 to 3-n. The television signal program source may be a normal television broadcast equipment, terrestrial broadcast or satellite broadcast, or it may be a program source for a cable television network. The television program source includes a teletext inserter and means for inputting the program class code into a teletext signal in a displayable and machine readable form. The code in a machine-readable form may be transmitted in an extension packet that is transmitted or not displayed within the display page of the teletext signal. On the other hand, the machine readable code sent within the display page does not appear to the viewer. The transmission medium 2 may take any convenient form, such as being broadcast by a terrestrial transmitter or a satellite transmitter, which may be a wireless file, or it may be a cable network for a cable TV system. The television receivers 3-1 to 3-n are connected to the program source via the transmission medium 2. [ Another possible program source 1 is a video tape or a disc on which a program is recorded for playback by a video tape recorder or video disc player. In this case, the transmission path 2 is a tape recorder and a disc player, The cable for connecting the player to the television receiver can be simplified.

An embodiment of a television signal program source according to the present invention is shown in schematic block form in Fig. The television program source includes a source of video and audio signals 10, which may be, for example, a television camera whose video output is provided to the transmission network 12 via a teletext inserter 11. The audio output from the television signal source 10 is provided to another input of the transmission network 12 via line 13. [ The conventional teletext editing system 14 is connected to the teletext inserter 11 and has another input provided from the TV access control equipment 15. [

The TV inhibitor control equipment 15 is arranged to insert into the teletext signal codeword classifying the contents of the television program produced by the signal source 10. The codeword is displayable and machine readable. The TV access control equipment 15 has a first input 16 for receiving data from a TV program scheduling system. Such data may provide an overall indication of the contents of the program that may be used to control the display of the program in the receiver. Information can define, for example, the level of violence, sexual content, language, or disastrous content that can occur in the program.

The TV access control device 15 has a second input 17 for receiving data from the recorded content. The recorded content may already include coding to indicate the type of content provided in the program and may include instantaneous data for classifying a particular event in the program. The keyboard or other input device 18 is connected to another input of the TV access control equipment 15. [ This allows the operator to insert the appropriate rating code into the live program. Of course, it is necessary to delay the actual transmission of the program for a short period of time in order to allow the operator to input the appropriate code at an appropriate time. Such transmission delays are well known to live broadcast programs that allow a broadcaster to block certain inappropriate occurrences, such as abusive or obscene comments of a person making a phone call during a live broadcast.

At this time, a code generated by, received by, and going to the teletext editing system is inserted into the teletext signal. The machine readable code may also be a displayable code, and may be transmitted separately at different locations on the display or in makeup packets that are not associated with or related to the page. In particular, the machine readable code may be inserted into selected bytes of packet 8/30 format 1 or selected triplets of packet 26.

Figure 3 shows the contents of packet 8/30 format 1 modified to insert machine readable code. This identifies the clock and information running in a certain period of time as packet 8/30 and includes an assembly code and byte containing information defining the initial page, network identity, time offset, modified Julian date and Coordinated Universal Time do. At this time, there are four bytes used in accordance with the present invention to transmit the rating code for the program. At this time, there is a byte that defines the status display.

The 4 bytes are provided with 32 bits which can be used to encode the data. It is desirable that the rating code be provided reliably because it annoys the viewer if the program is interrupted by false reception of the rating code. This fault protection can, of course, reduce the number of data bits that can be used to encode the class code. In an embodiment according to the present invention, these 4 bytes are used to transmit 16 message bits coded 4/8 for error protection. The plan for assigning these messages is as follows.

2 bits for the sexual content of the whole program

Two bits for the sexual content of individual events in the program

Two bits of violence content in the program

Two bits of violence content related to the events in the program

2 bits for the catastrophic events in the program

Two bits for a spurious language in the program

2 bits for the instruction in the start area of the program.

The allocation of two bits for each program content rating can be set to four possible levels with this particular content. For example, code 00 means no content of this type, code 01 means low level content, code 10 means medium level content, and code 11 means high level content. It is considered useful to have coding as far as sexual content and violence content relates to the entire program and individual events within the program. Thus, for example, a parent may decide to allow children to watch a program with low or intermediate sexual content as long as each event involving sexual content is suppressed. Therefore, the program level will be set to 01. However, if you want to remove all events with sexual content, you will set the event in the program code to 00. The same considerations apply to the violence content within the program. The rating of a disastrous content will only be for a limited time within the program. The types of content considered here are the details indicated by the surgery in the medical program. In this case, viewers may be interested in medical technology, but they can see terrible surgery. Another example of disastrous content is news or current affairs programs. For example, an interview with a recent bereaved person who can cause a person to be depressed, and an image that shows the effects of famine or other disasters. Since the language content of the program is intermittently frequent because it is normal, restraining the entire program on the basis thereof is presumed to be inadequate, and it is preferable that the moment when a false language is generated can be suppressed.

It is preferable that the area of the program start code has different ethnic codes in different areas and countries so that being classified as low level violence in one area can be classified as medium or higher level violence in another area. The same considerations can be applied well to sexual content and can also be applied to language content that is difficult or painful. In the aircraft cabinets, it is possible to transform the code for sexual content, violence, aggression or language content according to the code for the starting area of the program. Therefore, in the region (1), the middle level sexual content can correspond to the high level sexual content in the region (2).

It is also possible, for example, to exclude programs originating from a given area for political or religious reasons.

UK Patent Application No. 9619878.3 (PHB 33410) discloses a method and system in which a rating code is inserted into an extension packet of a teletext signal, especially in packet 8/30 format 1. The extension packet is not related to the page, but is frequently transmitted at intervals of approximately one second in the UK. If the TV receiver has adequate decoder and control circuitry, this is a convenient way for parents to control. However, at present, until a significant period of time has elapsed, many television receivers will be equipped with only the basic teletext decoder without the control circuitry at best.

Thus, the present invention allows a rating code for each program to be inserted in a displayable form on a selected teletext page, and in some embodiments a machine readable version to be associated with the selected page. This embodiment discloses three possible forms in which this association can occur.

The rating code displayed and detected by the control circuit in the first embodiment occupies a predetermined position on the displayed teletext page. As shown in FIG. 7A, there are four grades: language content, sexual content, violent content, and age rating. They are always located in rows 20 and 21 of rows 20, 21, 22 and 23. Thus, the control system can detect and interpret the data at the four positions and use it to either allow or suppress display according to the level set by the authorized person. This particular embodiment has the disadvantage of reducing the editorial freedom of the page editor and limiting the amount of information that can be displayed on the page.

In the second embodiment shown in FIG. 7B, a class code having a hidden character ( ^C _L ) at the head is included in one row. The first row may also be displayed as a blank space to separate the body of the teletext and the page mark, and this environment may be used to include a machine readable rating code without significant restrictions on editing. Also, if the code is not shown, a procedure for increasing the reliability of the data can be employed. It will be appreciated that in the first embodiment the rating code is protected by only one parity bit. In this example, the rating value is transmitted as data and the data is subjected to an 8/4 hamming test. A single bit error is then detected and corrected and a double bit error is detected and eliminated.

Table 1 shows a rating value, a transmission value, and a displayed character for the first embodiment shown in FIG. 7A. Table 2 shows a rating value, a transmission value, and a displayed character for the second embodiment shown in FIG. 7B , Where the values are transmitted using an 8/4 hamming test.

Rating value 4 2 5 18 Value transferred 34H 32H B5H 31H, 38H Displayed characters 4 2 5 18

Rating value 4 2 5 18 Value transferred 64H 49H 73H 49H, 02H Displayed characters d e s 1, graphics green

As can be seen in Table 2, the machine readable codes are displayed without being displayed and visually easy to understand. The problem with the device is that it can transmit a hiding attribute, for example code that terminates the operation of the graphic green. To prevent this from occurring in the displayed control code, insert a hidden attribute (transmission code 98H) after each character.

In the third embodiment, the machine readable rating data is transmitted via the triplet in the expansion packet 26. [ This has the advantage that machine readable data is hidden, making it more robust and avoiding the complexity of all edits. The data in the triplet in packet 26 is protected by a 24/18 Hamming code which identifies and corrects a single signal bit error and identifies and removes the Db bit error. Recent improved teletext specifications have a large number of unassigned triplets. If a row address triplet with a mode value of 01110 has been allocated for this purpose, 11 bits may be used for the rank data. This embodiment can be used to extend the PDC protocol for video recorders. To simplify the programming of the VCR, the teletext TV listing page carries the machine readable data in the loadable packet 26 to the VCR and stores it in the PICT 8/30 format 2 to define the identity of the current program. And controls the program recording in association with data broadcasting. Adding the rating data to the PDC data allows the rating to be checked when the program is recorded and when the viewer is informed of the rating of the program, and thus the recording can be suppressed.

In the fourth embodiment, the machine readable code is transmitted in packet 8/30 format 1 presented in UK patent application 9619878.3 (PHB 34110) and displayed in a form viewable on the selected page. As in the other embodiments, a viewer who has a teletext decoder but does not have a control system for suppressing display can visually monitor the rating of the program to manually switch the television receiver or prevent recording by the VCR can do.

The machine readable code need not necessarily be transmitted in direct connection with the selected page. The machine readable code may, for example, be transmitted in extended packet 8/30 format 1, which is not associated with any particular page, while the displayable code is transmitted on the selected page. As in the other embodiments, a viewer who has a teletext decoder but does not have a control system for suppressing the display can visually monitor the rating of the program to manually switch the television receiver or prevent the recording by the VCR can do. There is no direct relationship between the selected page and packet 8/30 format 1, but the station will obviously update both at the same time.

The advantage of having a machine readable code in the display page is that if some broadcasting parties who do not have the equipment for transmitting an extension packet broadcast the machine readable code, .

4 is a block diagram showing an embodiment of a television receiver according to the present invention. As shown in FIG. 4, the television receiver includes conventional antennas 20 for supplying tuners 21 and 1F and a demodulator block 22. The combined video and erase signals are available at the output of the block 22 and are supplied to the teletext decoder 23 and the color decoder 24. [ The output of the color decoder 24 is supplied to the video selector 25 which also receives the display signal output from the teletext decoder 23 and the erase signal via the OR gate 26 from the teletext decoder 23. [

The control processor 27 controls the operation of the television receiver in a conventional manner. This is used by the viewer to select a particular channel for the display and receives control commands from the remote control 28 to select other functions such as a teletext display or an on-screen menu display. The processor 27 may receive from the teletext decoder 23 a code that is provided in packet 8/30 format 1, i.e., a code representing the content of sex, violence, misleading content or poor language. In addition, a code for setting a level related to sexual content, violence, disastrous contents, or poor language content that can be accommodated in the display inputted by the user using the remote control device can be stored in the nonvolatile memory 29. The processor 27 compares the received code to the stored code and supplies it to the video selector 25 via the OR gate 26 in accordance with the output for this comparison, May be generated on line 30. It is also possible to supply a signal to the audio selector 32 via line 31 that can cause the audio output to be silenced in the appropriate environment.

The audio selector generates an output supplied to the standard video circuit 25 and the display device 36 while the audio selector 25 generates the output supplied to the standard audio circuit and loudspeaker 34 represented by block 33 and the video selector 25 . The audio selector 32 has another input supplied from a terminal 37 to which an optional audio source can be connected. This may be, for example, a tone generator that replaces a certain unpleasant word by a blip, or it may be connected to a supplemental channel, e.g., an ordeal channel, to provide an unpleasant word with an optional word. The Odette channel is proposed to be used to provide a voice assist signal that provides a description of the screen to aid in understanding the program of a person who can not clearly see the display screen or can not see it at all, for example, Channel. Typically, on the channel that allows alternate words for possible nasty words to be transmitted by the broadcast facility, or that it can be encoded in a given program source because the idle state is idle while communicating, There may be reserve capability.

4 shows a television receiver, the present invention can be similarly applied to a video recorder. In this case, the outputs of the audio and video selector circuits 32 and 25 may be supplied to the recording head on the video recorder. Therefore, only a program having an authorized code can be recorded on the video recorder. An optional device for a video recorder can record a received television program irrespective of the rating code associated therewith, but since such codes can be recorded on a tape, the television receiver at the time of playback is able to record And can respond to the output from the video recorder. In this manner, the program may be recorded for viewing by a number of different persons, each of whom may have a different acceptable rating level for a particular content. Therefore, the entire program is played through one television set, but only a limited version is played through the other set.

5A to 5E show screen display sequences in which a person can input a code into a television receiver. Initially, when switched on, the on-screen display prompts the visiting user to enter a personal identification number. It is assumed that the authorization is checked by the PIN. The PIN may be engraved in the memory by the manufacturer so that the buyer can know the PIN number so that the owner can initiate the selection of the rating. On the other hand, it is possible to set the private PIN to 0 in the factory and change the PIN to any number desired by the user in the process of inputting the set when the set is first switched on. Then, when a rating change is required, press the key on the remote control device that requires it. As a result, the user is prompted to input the PIN on the on-screen display.

At this time, the user inputs the PIN, and if this is correctly checked, the next on-screen display is provided. This is reference numeral (2) in Fig. 5A. Initially, the television receiver can be set to receive all programs, but it is possible to select a program of a certain type to be excluded by using the television access control system. The on-screen display instructs the user to press the key to continue processing, the red key at this moment. The next screen, the screen 3, prompts the user to press the green key to select the type of program that can be received or to press the red key if the user wishes to keep the status unchanged. Assuming that the green key is depressed, a fourth screen is provided. It is recommended that the user decide whether or not the program relating to the sexual content is excluded and recommends that the user press a predetermined button if such content is excluded and press another button if such content is not excluded . Assuming that the user intends to exclude certain sexual content, a screen 5 is provided. Here we ask the user whether to exclude high, medium or high levels or any level. In this example, the user chooses to exclude only the high level. In this particular example, the user selects to exclude only a high level of sexual content, then queries whether the content is excluded only when the event occurs, and whether all programs, including high level sexual content, should be completely excluded Receive. Again, the user is invited to press red or press green. This completes the programming of the sexual content.

A similar process occurs for violent content and appears on the screens 7, 8 and 9. The screens 10, 11, and 12 show processing to enable the disastrous contents to be excluded. In these special cases, disastrous contents are provided, but only events that do not occur in the entire program are excluded. It is assumed that the terrible contents are not related to the whole program but only to the events in the program. For example, such disastrous scenes may include surgical scenes within a medical program, accident scenes within a new program, or other disasters. These events are only a small part of these programs, and programs with these events may be interesting.

A similar process appears on the screens 13-15 to allow the programming of poor language content. Again, this excludes certain events rather than the entire program, since the occurrence of unpleasant words as a whole can be a small part of the program if a program with intense sex or violence is already excluded. The screens 16 and 17 represent the programming of the start area. The user can exclude the program in a predetermined area if necessary. This may allow an authorized person not to receive programs in these areas, for example, even if a particular area transmits an advertisement that does not contain excessive sexual content or violence content or disastrous content or spoken languages. On the other hand, the start area code can be effectively used to modify the code for sex, violence, cruel contents, or poor language depending on the source of the program. Therefore, it is preferable that the level of the sexual content received from the region A is a medium level because the middle in the region A can be regarded as high in the region where the receiver is disposed. Such a change code may be permanently programmed in the aircraft or may be set by the user. The screen 18 is the last screen provided and confirms the selection made by the user. This screen is similar in content to the screen 2 provided when an entry to the access control system is obtained. Therefore, when the setting is made, it can be displayed on the screen 2 at the time of subsequent access.

The on-screen display message is only an example, and the actual message may be modified in a particular market and may be the language of the country in which the setting is made. Of course, the control processor can be variously stored in a number of different languages on a screen display, where language selection may be made by the user when accessing the on-screen display, so that a common control processor Can be enabled.

6 shows an example of an on-screen message displayed when the access control system is in operation. For example, the first screen represents a case where the program is unavailable due to a high level of sexual content. This message is determined by the coding associated with it, as well as being able to change depending on why the particular program is not available. The second screen indicates that the television is randomly erased due to normal levels of violence. Therefore, during most programs, the display can be used, but it randomly clears the clear display to prevent viewers from seeing the violence content. Likewise, the third screen indicates that the display is randomly erased due to the disastrous contents. The fourth screen shows the displayed image together with a message indicating that the speech has been silenced due to poor language. Therefore, the viewer will not think that the audio channel of the television receiver has failed because the viewer informs that the audio is arbitrarily silenced.

In a particular example, the user's permission to change the coding is done by PIN. However, there are several other ways that the user can be authorized. One possibility is a fingerprint detector, wherein the user simply places the user's hand or fingerprint on a detector pad that compares the fingerprint stored in the image plane with the fingerprint of the user. In this way, it is possible to prevent certain problems such as forgetting the PIN, for example, causing the PIN to be damaged and resetting the rating code. Another possibility is to include a video camera on the water surface that can be seen in the presence of a person who wants to change the code. The output of the video camera is compared with the image stored in the receiver, and if it is judged to be the same, the rating code can be updated. The above two methods can be used, for example, when a personal computer is equipped in a TV program receiver facility. At this time, the processing circuitry required for fingerprint or facial recognition may be in the personal computer circuitry.

Television broadcasters will often notify viewers about the suitability and content of the program just before the program begins, if it is determined that the program is confusing or disturbing the viewer. However, if the viewer watched the program after the program started, it would not know such warnings or other given information.

Teletext services provide information on a wide range of topics, including TV listings and TV program related material. The teletext service provider may also be a TV program provider, so they may know more about the contents of the TV program. Alert information related to the suitability and content of a particular program may be broadcast as part of a TV listings page or as part of a page that provides a detailed description of a particular program. In addition, when the information relates to an existing " over-the-air " program, the information may be transmitted on a dedicated page number, so that the viewer only has to remember a page number to inspect the current program details. Whichever method is employed, the suitability and content of the information is available as long as the program is on air.

If a dedicated page number is used, there is a disadvantage that a viewer must memorize different page numbers for each channel that can be received. Also, if the service provider reorganizes the database and assigns the warning page to another page number, it can not be protected. Also, not all service providers will use the same page number. For this reason, it is difficult to build a database that freely edits and uses a page number group for a predetermined category and section. Some teletext service providers do not have access to the full range of possible page numbers. These broadcasting rights or licenses are intended to use only a predetermined page number.

One possible solution is to store the appropriate page number for a given channel in a nonvolatile memory located within the receiver, but this method requires the action of the viewer and is difficult to achieve in a simple manner. However, if this is done, the viewer may have the means to press the one remote control button at any time to display the page, and the TV receiver may be designed to automatically display the page after changing the channel , There is still no way to prevent the problem that the broadcasting station is generated by changing the page number. In addition, the system may be configured such that the page is displayed automatically when the page appears during transmission (when the page is transmitted only when the issuer issues a warning), or may be updated at the time of program change. The setting of the update control bit C8 of the page header can be interpreted when the flags indicating its contents are changed.

A recent enhanced teletext specification specifies a teletext page, or magazine inventory page (MIP). The page indicates the function and contents of another page in the magazine in which the MIP is transmitted. An 8-bit value (sent in two 8/4 Hamming encoded bytes) is transmitted for each possible three number page number (m00-mFF). One such category is the TV program related warning page (code 7AH). This is a single page (that is, not a circular page), so that the suitability and contents of the program can be visually read.

The decoder searches the magazine inventory page on each channel and appropriately records the page number of the TV program related warning page in the nonvolatile memory. Therefore, there is no need for the user to participate in configuring the system because the channel for broadcasting the MIP containing the appropriate data is automatically set. Inspections may be performed at periodic intervals to ensure that the stored page numbers remain valid. Once the page number is opened, any or all of the above-described methods (single button access, indication for update, indication for appearance and indication for channel change) may be provided.

The system described above provides human readable information on the standard teletext page for the suitability and content of the TV program. The present invention extends this to allow access to the program to be suppressed. The present invention in some embodiments allows machine readable data to be transmitted as part of a page so that the receiving device can be controlled. The machine readable data includes error protection to ensure reliable data, since the viewer will feel uncomfortable when pseudo blanking of the program occurs. The data may define a rating for the content of the program in multiple categories, such as poor language, sexual content, violent content, and the like. The minimum age is also recommended. Therefore, the information provided visually is defined in a qualitative way.

The rating data can be interpreted by a TV equipped with appropriate equipment, and when the threshold range is exceeded, display of images and sounds can be suppressed. In this way, parents can prevent their children from watching certain programs or program types that are deemed inappropriate for them. In addition, by installing a decoder suitable for the VCR, it is possible to prevent the recording of a program that is deemed inappropriate. The TV or VCR is provided with a user interface so that the parent can set or change a threshold value having an initially inputted identification code (PIN number).

It will take a considerable amount of time for all TV and VCR receivers to be controlled in this manner. However, it is desirable to provide the suitability and content of the information to many receivers as soon as possible, which can be easily achieved by linking the access control data with the visual description on the teletext page.

The machine readable data can be added to the TV alert page in various ways. For example, as code embedded in the display portion of the page, or in a page-related extension packet (packets 24-28). The latter method seems to be more certain because the coding structure employed by some of the extension packets is better protected against transmission path errors by using Hamming coding. However, since some transmission systems can not transmit extension packets, in this case the parity protection data of the normal display packet should be used.

The normal teletext page uses packet 0 to convey the Hamming protection control data for the page number of the page and various display attributes. It also includes a page number, date, and text that indicates the time of the service provider and the area, usually in a form that can be displayed directly on the top of the page. Typically, portions other than the directly displayable portion of the page are transmitted through Packets 1 through 23, and Packet 24 is used in some transmission schemes to provide redundant display rows to simplify database retrieval.

The location of the various codes used to convey the different ratings can be defined by establishing an agreed format for the TV alert page. It is therefore possible to determine where the appropriate decoder records data and to determine whether the program is provided on the TV screen or VCR. In implementing the present invention, it is desirable to place a practice code between the broadcaster and the manufacturer to outline the format and layout of the page.

In the embodiment shown in FIG. 7A, the language class is known in the packet 20, column 21, the sexual content class is known in the packet 21, column 21, the violence content class is in the packet 22, column 21, Can be found in the packet 23, 20 and 21 columns. Here, the display data is also machine readable data, and additional codes need not be transmitted.

The simple system as described above satisfies the basic requirements for delivering content ratings, but it does require any page format that restricts edits and is not acceptable to all teletext service providers.

As an extension of the proposal, rating data may be coded in a predetermined row. Since machine readable data may not be detected by the viewer, it may be desirable to suppress the display of the data in some manner so that the row appears to be empty. There are a number of possibilities:

- Insert the control attribute Conceal at the beginning of the sequence. If necessary, two consecutive Conceal codes can be used to make it more certain.

- If the page is designed with a subtitle / news breaking format, the rating data will not need to be preceded by the Start Box attribute and will not be displayed as a result.

- Set the background and foreground colors the same.

- Inserts data into the row immediately below the row that contains the Double Height control attribute.

Practical systems will require practice codes to determine the order of rows, rating data, and possibly how to hide data. This method makes editing much more free than the apparatus shown in FIG. 7A. The remaining lines of the page other than the specified line can be configured as desired by the editor.

The first line is often marked blank and can be assigned for this purpose, distinguishing the text of the text from the page header. FIG. 7B shows how the grades visually provided in lines 20 to 23 are sequentially input after the hidden control attribute ( ^C _L ) of the first row.

In the above example, the value employed in a particular class is a value displayed on the screen when the transmitted code is displayed on the TV screen through the display circuit for the teletext decoder.

Value sent: 34H 32H B5H 31H, 38H

Rating: 4 2 5 18

Also, if required by the selected coding scheme, a value between 10 and 15 may be provided in hexadecimal format (e.g., A through F) and a value between 16 and 255 provided in two hexadecimal code values .

Note that in the above embodiment, a plurality of categories may be included until all the rows are filled. The new category may later be added to the right end of the sequence and will remain compatible with the previous decoder.

Also, although a viewer using the dedicated remote control button to select a TV alert page will receive the page, the minimum condition for the page is the page header and the packet 1. Instead, if a broadcast station wishes to supply access control data without accompanying text, a page number having both a page unit set as a hexadecimal number and a page ten can be assigned. At this time, the practice code can define the combination as a page having access control data, but can not display contents directly. A page number having a hexadecimal number associates a page with access control data and displayable contents, but is selected by automatically responding to a dedicated remote control button, channel switching, updating, and the like.

If the page unit of the page number and the page ten element are both in the range of 0 to 9, the page will be directly accessed to all teletext viewers through a normal page selection mechanism for entering three numbers.

While this embodiment satisfies the requirements of a given system, it is especially true when the data for controlling access to the program is protected only by parity coding and does not detect but correct a single bit error. The decoder should be designed to check multiple consecutive data receptions and to accumulate the results before determining the rating for the current program.

The reliability of the data for the assigned packet can be improved by transmitting the rating value via 8/4 hamming test data. Then, a single bit error is detected and corrected, and a double bit error is detected and rejected. The Hamming coded value represents a rank value.

Rating: 4 2 5 18

Sent value: 64H 49H 73H 49H, 02H

Displayed characters: d I S 1, graphics green

Note that this will no longer produce a display that can be interpreted visually. It can also send code to terminate the action of the hidden attribute, ie, graphics green. To solve this, a hidden attribute (transmission code 98H) is inserted after each element to hide the data.

Rating: 4 2 5 18

Values transferred: 64H, 98H 49H, 98H 73H, 98H 49H, 98H, 02H, 98H

A simpler decoder does not have the option of capturing data and checking that data as if it were a parity code. Therefore, it is necessary to apply the received data to a lookup table or a reference table to establish an actual rank value. More complex decoders can immediately perform Hamming 8/4 checks, which allows more flexibility in processing and checking for any byte.

Since the machine-readable class data is hidden, the data is transmitted through the triplet in the expansion packet 26. [ They are coded Hamming 24/18, allowing single bit errors to be identified and corrected, and double bit errors being identified and rejected.

The recently improved teletext specification has a large number of unassigned triplets. For example, if the mode value of 01110 is assigned to the row address triplet, 11 bits can be supplied to the rank data.

Address bit: 11xxxx 2 When MSBs is set to 1, N.B., "Row triplet" appears

Mode Bits: 01110

Data bits: xxxxxxx

The structure using the packet 26 may be used to extend the PDC protocol. In order to simplify the programming of the VCR teletext, the TV listing page can carry machine readable data in the packet 26, which in combination with the packet 8/30 can send a format 2 broadcast identifying the current program It can be loaded into the VCR to control the recording program. If the rating data is added to the PDC data, the VCR will check the rating when programming is requested and notify the viewer if the program can not be recorded because of the threshold currently set in the VCR.

It will be apparent to those skilled in the art that other modifications may be made by the present invention. Such variations are well known in the art of designing and using the television system and its components, and may include other features that may be used instead of or in addition to those described above. While a combination of these features is set forth in the claims, the scope of disclosing the invention should not be construed as an attempt to solve all or part of the same technical problems as the invention contemplates, Including any novel combination of features or features implicitly or explicitly disclosed herein, or a generalization of one or more such features obvious to one skilled in the art. It is to be understood that the invention is capable of other and different combinations of these features or of any other applications derived therefrom during the practice of the invention.

Claims (14)

CLAIMS What is claimed is: 1. A method for allowing authorized persons to disable the audio and / or video display of a television program or a portion of a program according to program content, I) classifying the entire and / or momentary content of the television program; ii) generating a codeword representing the assigned class, iii) inserting the codeword into a machine-readable form and a displayable form into a teletext signal multiplexed with a television signal representing the program ≪ / RTI > The method of claim 1, wherein the displayable code is displayed at a predetermined location on a teletext page, and the machine readable code is code for generating the displayable code at the predetermined location. 2. The method of claim 1, wherein the displayable code is freely located on a teletext page and the machine readable code is located at a predetermined location on the page. 4. The method of claim 3, wherein the machine readable code is hidden from the display. The method of claim 1, wherein the machine readable code is included in an extension packet associated with the displayed page. 6. The method of claim 4 or 5, wherein the machine readable code is protected by an error correction code. The method of any one of the preceding claims, wherein the rating code is inserted into a current program page that includes displayable information associated with a currently transmitted program. 8. The method of claim 7 wherein the transmission frequency of the current program page is incremented when any change in the rating code occurs. 9. The method of claim 7 or 8, wherein the transmission frequency of the current program page increases as the level of the class increases. The method of any of the preceding claims, comprising providing another word to replace a word that is deemed unsuitable for the selected grade level. A method of disabling audio and / or video display of a television program, iv) setting rights of a user defining a program to be disabled or a part of the program; v) inputting a code word corresponding to a program content to be suppressed in a memory in the television receiver, vi) receiving a television signal generated by a method as claimed in the preceding claims, vii) comparing the received codeword with the input codeword, viii) disabling the voice and / or image display according to the comparison result ≪ / RTI > Means for classifying a television signal to be transmitted in accordance with program content, means for generating a code word indicative of a class assigned to the program or portion thereof, In a readable form. ≪ RTI ID = 0.0 > [0002] < / RTI > CLAIMS What is claimed is: 1. A recording medium comprising data representing a television program, a rating code word representing an assigned rating for full and / or instantaneous content of the program and an associated teletext signal, Wherein the codeword is included in the teletext signal in a displayable form and in a machine readable form. 13. A television receiver suitable for receiving and displaying television signals from the television signal source claimed in claim 12 or the recording medium claimed in claim 13, A teletext decoder, means for extracting a machine readable code word indicative of the class assigned to the currently received program, means for displaying the displayable class code, any program class indicating a program for which display suppression is requested Means for comparing the input rating with the received rating, and means for allowing or disallowing display of the program in accordance with the comparison result.