Television receiver, method of providing a message to such a receiver, and system arranged to execute such a method
The invention relates to a television receiver, comprising a teletext decoder, for retrieving and decoding teletext data from a broadcast signal, and arranged to retrieve teletext data comprising messages, further comprising a processor for generating a video signal including the messages in a format suitable for display on a screen. The invention further relates to a method of providing a message to one or more television receivers, comprising receiving a message to be provided to the television receiver(s), converting the message into teletext data, and providing the teletext data to a teletext inserter for insertion into a television broadcast signal.
The invention also relates to a system arranged to carry out such a method, and to a computer program having the potential, when run on a computer, to make the computer execute such a method.
Examples of a television receiver and method of the types mentioned above are known, for example from WO 01/72038.
The known method comprises assigning at least one text page to the delivery of information services, receiving information, encrypting the information to include commands, formatting the encrypted information and commands as packet message signals, transmitting the formatted packet message signals as at least one text page, receiving the text page, decrypting and parsing the packet message signal to recover the commands and using the command to operate on and/or display the information as desired. The selection of the relevant text pages is controlled by a user having a remote controller for a television receiver. Once the user has selected the page(s) associated with a message service, the messages are displayed on the television screen.
The known method has the disadvantage that the user must call up the page(s) associated with a message service, and search for messages intended for him. It is an object of the invention to provide a television receiver and method of the types mentioned above, that allow messages to be directed to specific receivers.
This object is achieved by the television receiver according to the invention, which is characterised in that the television receiver is arranged to store at least one code, and
to only select for inclusion in the video signal messages with a code corresponding to the stored code.
Thus, a television receiver can recognise messages intended for it. Only those messages are included in the video signal. The user will therefore automatically only see those messages intended for him on the display device with which he is viewing the messages.
Preferably, at least one of the codes is stored in a fixed manner. Thus, a certain measure of security is provided, in that a television receiver cannot be modified to receive messages with a certain code intended for another receiver. Additionally, a manufacturer of a television receiver is always able to send messages to owners of the receiver, since he will know the code, which cannot be changed.
In a preferred embodiment, the television receiver is arranged to continually scan the teletext data to detect messages with a code corresponding to the stored code, and is capable of being run in a mode wherein the messages are automatically included in the video signal upon detection of a message with a code corresponding to one of the stored codes. Thus, provided the receiver is switched on, a message can be flashed across the screen as soon as it has arrived and been decoded. The user no longer has to switch the receiver to the teletext mode, or select a pre-determined page to check for messages. He is made aware of their arrival almost instantly. Preferably, the processor is arranged to generate the video signal in such a way that, when displayed on the screen, the message continuously moves across the screen.
Thus, no limitations exist on the length of the message in terms of the number of characters. The message is simply scrolled across the screen.
According to an aspect of the invention, a method of providing a message to one or more television receivers is provided, comprising receiving a message to be provided to the television receiver(s), converting the message into teletext data, and providing the teletext data to a teletext inserter for insertion into a television broadcast signal. The method is characterised in that one or more codes, associated with the television receiver(s) are included with the message in the teletext data. Thus, the teletext data is generated from a message to be sent to certain television receivers. The method allows messages to be addressed to specific television receivers or groups of television receivers according to the invention.
One embodiment of the method according to the invention comprises retrieving from the received message a specification of one or more intended recipients, and converting the specification into the code(s) included with the message.
Thus, messages, e.g. e-mail or short messages sent by a mobile phone, are scanned for a specification of their destination, and converted into a format that allows the message to be forwarded by means of teletext packets to their intended recipients.
According to another aspect of the invention, a system is provided, arranged to carry out the method according to the invention.
According to yet a further aspect of the invention, a computer program is provided, having the potential, when run on a computer, to make the computer execute a method according to the invention.
The invention will now be explained in further detail, with reference to the accompanying drawings.
Fig. 1 shows an overview of a system comprising a television receiver according to the invention and a server programmed to execute the method according to the invention.
Fig. 2 shows schematically the composition of a teletext service, in which the invention can be implemented.
Referring to Fig. 1, an example of a system in which the messaging method of the invention has been implemented will first be explained. It is assumed that the message is intended for the user of a television set 1. The television set 1 is merely an example of a suitable television receiver. Other examples include set-top boxes and suitably programmed personal computers. The television set 1 can be an analogue or digital set, or be capable of receiving both types of broadcast. The television set 1 is capable of receiving and displaying teletext services. In the present context, this includes all manners of data embedded in broadcast signals that further comprise a video component, and usually an audio component. This can be teletext data inserted into the Vertical Blanking Interval of an analogue television signal, as well as teletext services provided with a digital video broadcast signal, as part of an MPEG-stream, or with Serial Digital broadcast.
Inside the television set 1, a teletext decoder separates the teletext data from the broadcast signal. The teletext decoder, or a separate microprocessor, converts the teletext data, and generates a video signal suitable for driving a display, or for transferring to a display device. The displayable part of the data is either superimposed on the pictures comprised in the video component of the broadcast signal, or replaces it. Many possible arrangements of decoder or decoder and microprocessor are possible, depending on the type of television receiver. There can be one single decoder chip with elaborated processing features, a so-called system on a chip, carrying out all video processing in the television set 1, or a combination of a teletext decoder chip and a microprocessor with ROM in which instructions for the microprocessor are stored. These, and other variants, are well known in the art.
The following description will assume that the television set 1 is equipped to receive and decode teletext services conforming to European Television Standard 300 706. Fig. 2 shows the composition of such a teletext service. The teletext data is comprised in packets 2. Packets 2 are grouped into pages 3. Each page 3 comprises a header packet, comprising the page address, and a number of displayable packets. The transmission of a page 3 begins with, and includes its page header packet. The pages 3 are grouped into magazines 4. There are eight magazines 4. The first digit in each page number denotes the number of the magazine 4 to which the page 3 belongs. Normally, the pages 3 in a magazine 4 are transmitted in numerical sequence. There are also a number of packets 2, marked X/30 and X/31, which comprise service related data. These packets can be inserted at any point within the transmission.
According to the invention, packets X/31 comprise data encoding messages with a code accompanying each message. The data encoding the messages is thus comprised in packets that are not associated with a particular teletext page. This has the advantage that no page header packet need be sent with the messages. Only the packet comprising the message is sent. In addition, because the service related packets can be inserted at any point in the sequence of packets 2 associated with magazines 4 and pages 3, it is possible to vary their number according to demand and to avoid delays due to the need to cycle through the pages 3 and magazines 4.
The television set 1 stores at least one code. The television set 1 is arranged to continually scan the teletext packets X/31. If it detects a message with a code corresponding to any of the stored codes, it retrieves this message, converting it into a format suitable for
display. The other messages are not retrieved, decoded and converted into a video signal. Thus, only messages directed at the television set 1 are processed by it.
It is noted that the code need not necessarily be unique to the television set 1. Embodiments are conceivable, wherein groups of television sets 1, for example of a particular type, store the same code, or a same code component. In this way, for example, a manufacturer can direct messages at all the owners of a particular type of television receiver. The invention is very effective for this purpose, since the manufacturer does not need to keep address records of the owners of appliances.
One advantageous implementation would be one in which the television set 1 stores a unique code and a group code. Thus, messages can be addressed to individual receivers, but also to groups of receivers. In the latter case the group code can be used to avoid having to send the same message many times over, each time with a different unique code.
Preferably, at least one of the codes is stored in the television set 1 in a fixed manner. This means that it is stored in such a way that it cannot be modified. Preferably, it is hard- wired or hard-coded into the television set 1. A logical implementation would be for the code to be compiled into the instructions stored in the processor that processes the teletext data from the packets X/31. Other variants, for example a code separately stored in ROM, are possible. Preferably, the television set 1 can operate in a mode, wherein the teletext data is scanned in the background, for example whilst the user is watching the normal television video broadcast. As soon as a message directed at the television set 1 has been detected and converted, it is flashed across the screen, as a picture in picture for example. Thus, the message is instantly communicated to the user. The invention provides a push mechanism, wherein the user does not have to switch the television set 1 to a teletext display mode and retrieve a special page, but is made aware of the arrival of message whilst watching the normal programs. The television set 1 can operate exclusively in this mode, or switch to this mode.
Preferably, the television set 1 is able to scroll the message across the screen. This allows longer messages to be sent, that cross the boundary of the number of characters that can be displayed in one line. The invention allows the transmission of such longer messages, as the code is included with each packet X/31 comprising a part of the message. The message can thus be spread across a plurality of packets. This allows long messages to be sent.
Of course, in a digital interactive television receiver, it would be possible to acknowledge receipt of the message. However, the invention is also suitable for television receivers that are not interactive. Because the television set 1 may be switched off at the time of broadcast of a message, messages are repeatedly broadcast. Each time a message is broadcast, a time stamp encoding a time of first transmission is broadcast with it. The television set 1 is capable of storing received time stamps. It is arranged to compare the time stamp retrieved from the teletext data with those retrieved and stored earlier. In this way, it is capable of preventing later received messages with the same time stamp from being flashed across the screen. Referring back to Fig. 1 , the way by which a message reaches the television set 1 will now be explained. The television set 1 receives the broadcast signal from a broadcast head-end 5, through a cable, satellite, or terrestrial transmission. The head-end 5 is connected to, or comprises, a teletext inserter 6. The teletext inserter 6 receives the video and audio broadcast signal from a broadcast provider 7. In the embodiment of Fig. 1 , there is a direct network connection between the teletext inserter 6 and a teletext workstation 8, on which the teletext data comprising the messages is composed. Of course, the teletext data can also be provided on a recording medium, in case the teletext inserter 6 and teletext workstation 8 belong to different entities. The teletext workstation 8 is operated by a service provider. It is conceivable that the teletext inserter 6 inserts teletext data from different providers. It can, for instance, receive the packets X/31 from the teletext workstation 8, and other packets 2 from a regular broadcasting entity with a similar teletext workstation (not shown).
The teletext workstation 8 carries out the steps of receiving messages to be provided to the television receiver(s), and converting the message into teletext data, thereby including the time stamps and codes by which e.g. the television set 1 is addressed.
Messages can be entered manually from paper or dictated to an operator of the teletext workstation 8. Preferably, however, the handling of messages is done automatically. In this embodiment, messages are provided to the teletext workstation 8 from a message server 9, connected to a communications network 10. The message server 9 can also be operated by the service provider. Messages can be communicated to the message server 9 in a way similar to the way short messages for mobile phones are communicated. Such mechanisms are known, and will not be discussed in any great detail here. It suffices that the processing carried out by the teletext workstation 8, or possibly the message server 9 can comprise retrieving from the received message a specification of one or more intended
recipients, and converting the specification into the code(s) included with the message. Such a specification can be in a body, header or address of the message sent to the message server 9.
The message can reach the message server 9 from a computer 11 connected to the network 10. Alternatively, a short message entered on a mobile phone 12 can be transmitted through a cellular network 13 to a short message centre 14 connected to the communications network 10. On its way, specifications of the address of the television set 1, can be converted one or more times into different formats, depending on the mode of transmission, hi the end, though, the teletext workstation 8 uses this address to include a code with the message in the teletext data sent to the television set 1.
It will be appreciated that the invention is not limited to the embodiments described above, which can be varied within the scope of the attached claims. For example, the code stored in the television receiver can be made transparent, i.e. spread among potential senders of messages. They can include the code in the body of a message, sent to the message server 9.