RECEIVER FOR AND METHOD OF DISPLAYING TEXT DATA

Abstract: The invention relates to a receiver for and a method of displaying text data. For example, a television receiver (1) for displaying teletext data (D), comprising a receiver (21) for digital character codes and a memory (23) containing character sets (000, 001, ...) that transform the character codes into characters displayed on a screen (3), with user-selection means (41) for the character set. Character sets are usually divided into blocks (I, II, ...). In a further embodiment, the invention provides user-selection means at block level to limit the amount of choices. Within a block, the character set to be used is determined by a 3-bit language code in the header of a teletext page. In a practical embodiment, a language I/II button (41) for audio is used in the teletext mode to select from at least two blocks. In a further practical embodiment, this selection is stored in a non-volatile memory (7) for each preset. This invention provides an easy way of selecting a character set for the representation of characters.

Description: Receiver for and method of displaying text data. The invention relates to a receiver for displaying text data, comprising means for receiving digital character codes, a memory for storing at least two character sets for converting the character codes into characters on a screen, and means for selecting one of the character sets. The invention also relates to a method of displaying text data on a receiver, comprising the steps of receiving digital character codes and selecting a character set from a memory in which at least two character sets for converting the character codes into characters on a screen are stored. Research Disclosure, December 1994/695 describes a receiver for and a method of displaying teletext data. In teletext data, a 7-bit character code is used for each character position on a teletext page. The character associated with a character code is defined in a character set. The character set converts the character code into a character on a screen. Per character position, a maximum number of 128 different characters can be displayed in this way. To meet the user's wish to display characters which are specific of a given language, different character sets are defined. Per teletext page, a character set may be defined by a 3-bit language code which is present in the header of each page. With this code, the broadcasting station can make a choice from a maximum number of 8 different character sets. Since there are more than 8 languages in Europe, more than 8 character sets are desirable. To realize this, different blocks are defined, each consisting of a maximum number of 8 character sets. A block generally comprises the character sets of the languages spoken in a given region, for example, Western Europe or Eastern Europe. Different blocks are present in a receiver. The block that is used is set in advance in the factory, in conformity with the geographical region. A problem arises when the broadcasting station starts from a different default setting. This is the case, for example, when the receiver is present outside the region of the broadcasting station, which is often the case with satellite reception. An example is the reception of MTV in Poland. The broadcasting station will use, for example, the language code indicating the English character set in the Western European block. Upon reception in Poland, however, the teletext receiver will use character sets from the Eastern European block in accordance with its default setting. The teletext pages will then unintentionally be displayed in Polish characters because the language code for the English character set from the Western European block indicates the Polish character set in the Eastern European block. A solution to this problem is known from said Research Disclosure. By means of language analysis, the correct character set is derived from the character codes. In accordance with this article, this may be realized, for example, by comparing frequently occurring character strings in the teletext data with character strings that frequently occur in a given language. The character set is then selected in conformity with the result of the language analysis. This method is difficult to perform and it is not certain that the correct solution is achieved. It is an object of the invention to provide a different and simpler method of selecting a character set for a correct display of characters. To this end, the receiver according to the invention is characterized in that the means for selecting one of the character sets comprise a selection means which can be operated by a user of the receiver. The invention thus enables the user to select the character set. A simple and efficient method is then obtained. When characters are displayed incorrectly, the character set can be modified by means of the selection means so that the characters are displayed correctly in the user's judgement. As already stated hereinbefore, character sets in teletext are generally grouped in blocks. To limit the quantity of selection possibilities, a selection at the level of these blocks is preferred. In a preferred embodiment, the user-selection means are adapted to select one of the blocks. A receiver may comprise a language selection button for audio. A further embodiment of the invention is characterized in that, in a text mode of the receiver, the language selection button is adapted as the selection means. It is preferred to store the last made choice of a character set or block. This may be effected by making use of a non-volatile memory for storing presets. In one embodiment, the non-volatile memory is adapted to store the setting of the selection means per preset. This information is used during renewed tuning to a preset so as to display the characters directly in the preset. These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter. In the drawings: Fig. 1 shows the general structure of a television receiver according to the invention. The Figure also shows the elements in so far as they are necessary for understanding the invention. Fig. 2 is a diagrammatic, more detailed representation of the memory for storing the character sets. Fig. 1 shows the general structure of a television receiver according to the invention. The television receiver 1 comprises a teletext decoder 2, a display screen 3, a remote control unit 4, an infrared receiver 5, a microprocessor 6 and a non-volatile memory 7. The teletext decoder 2 comprises a receiver 21 for receiving character codes, and a selector 22 for selecting a character set to be used from a memory 23, in which character sets 000, 001, ... are stored. For the sake of simplicity, only two character sets are shown in Fig. 1. These character sets convert character codes into characters on the display screen 3. The means for selecting a character set from the memory 23 not only comprise the selector 22 but also the remote control unit 4, the infrared receiver 5 and the microprocessor 6. The nonvolatile memory 7 for storing presets will be described with reference to a further embodiment. Teletext data D is received in the decoder and the character codes are received in the receiver 21. The character set that is used for displaying the character is determined by the selector 22 which is controlled by an output of the microprocessor 6. According to the invention, the selection means are provided with a user-selection means which, in this example, forms part of the remote control unit 4. The signal from the remote control unit 4 is received via the infrared receiver 5 in the microprocessor 6, whereafter the microprocessor activates the selector 22. The character sets are generally divided into blocks. A selection at block-level is recommended to limit the number of selections. For the sake of clarity, a preferred embodiment will be described with reference to Fig. 2. Fig. 2 is a diagrammatic, more detailed representation of the memory 23 for storing the character sets. In the memory 23, the character sets are subdivided by way of example into two blocks I and II of eight character sets each. Block I is, for example, a Western European block and block II is an Eastern European block. A 3-bit language code, which is present in the header of a teletext page and is received, for example, in the receiver 21, indicates which character set from a block must be used. For example, a language code 000 may indicate both 1/000 (English character set) and 11/000 (Polish character set). A broadcasting station can determine the selection of the blocks by means of a packet 28/29. However, in many cases, this packet is not transmitted. In that case, a default setting determines which block will be used. In one embodiment of the invention, the selection means, here a component of the remote control unit 4, is adapted to select one of the blocks. In a preferred embodiment, a language selection button is used as the selection means. Such a button is customary for the language selection for the audio channel of a television receiver. In the case of a television program which is broadcast in several languages, the language can be set by means of this button. In accordance with an embodiment of the invention, this language selection button is adapted as a selection means in a teletext mode of the receiver. In this way, an already existing button is given an extra function and no other button needs to be provided for the character set selection. Generally, this button is present on the remote control unit 4, but another location is alternatively possible. Preferably, it is a I/II language selection button as is denoted by the reference numeral 41 in Fig. 1. This is a language selection button which, in principle, provides two selection possibilities. The selection between at least two blocks with character sets then takes place with this I/II language selection button. In the case of two blocks, the two blocks correspond to the two selection possibilities of the I/II language selection button 41. If there are more blocks in the memory, they may be selected, for example, cyclically. Whenever the language selection button is pressed, a subsequent block is selected. The language selection button 41 is preferably used for the block selection, but may be alternatively used for the character set selection. The setting of the selection means is preferably stored, for example, in the nonvolatile memory 7. This is a memory which is used for storing presets. Per preset, the setting of the selection means is stored. In the case of two blocks, such as described by way of example, it is sufficient to use 1 bit per preset. More bits are required for a selection from more blocks or character sets. When the television receiver 1 is being installed, the default settings for the block selection and the character set selection are stored in the non-volatile memory 7 in conformity with the region and the preferred language. When the teletext mode is activated, the settings are retrieved from the non-volatile memory 7. The characters on the teletext pages are displayed in accordance with the instantaneous block selection and character set selection. The block selection can be set with the language selection button 41. The character set selection will generally be determined by the language code which is present in the header of the teletext page, but may be alternatively set by means of the language selection button 41 or by other buttons on the remote control unit 4. When leaving the teletext mode, the settings of the selection means are stored in the non-volatile memory 7. The invention is not limited to a television receiver. For.example, the invention may be alternatively used in a VCR, a set-top box, a PC with teletext decoder, etc. The use of the invention is further not limited to teletext data; applications in other receivers for displaying text data, such as RDS, are alternatively possible. It should be noted that the above- mentioned embodiments illustrate rather than limit the invention. Those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses to elucidate the claims shall not be construed as limiting the claim. The word "comprising" and its derivatives do not exclude the presence of elements or steps other than those listed in a claim. The invention may be implemented by means of separate elements, as well as by a correctly programmed computer. In the claims relating to the receiver, in which various means are mentioned, several of these means may be implemented in one and the same piece of hardware.

Claims: CLAIMS: 1. A receiver (1) for displaying text data (D), comprising: means (21) for receiving digital character codes, a memory (23) for storing at least two character sets (000, 001, .... ) for converting the character codes into characters on a screen (3), and means (4-6, 22) for selecting one of the character sets, characterized in that the means (4-6, 22) for selecting one of the character sets comprise a selection means (41) which can be operated by a user of the receiver (ϊ). 2. A receiver (1) as claimed in claim 1, characterized in that at least two blocks (I, II, ...), each comprising at least two character sets (000, 001, ... ), are stored in the memory (23), the receiver further comprising: means (21) for receiving a digital language code indicating a character set to be used from a block, and means (4-6, 22) for selecting one of the blocks, the user-selection means (41) being adapted to select one of the blocks. 3. A receiver (1) as claimed in claim 1, characterized in that the receiver (1) further comprises a language selection button (41) for audio, while, in a text mode of the receiver (1), the language selection button (41) serves as the user-selection means (41). 4. A receiver (1) as claimed in claim 1, characterized in that the receiver (1) further comprises a non-volatile memory (7) for storing presets, the non-volatile memory (7) being adapted to store a setting of the user- selection means (41) per preset. 5. A method of displaying text data (D) on a receiver (1), comprising the steps of: receiving digital character codes, and selecting a character set from a memory (23) in which at least two character sets (000, 001, ... ) for converting the character codes into characters on a screen (3) are stored, characterized in that one of the character sets is selected by means of a selection means (41) which can be operated by a user of the receiver (1). 6. A method as claimed in claim 5, characterized in that at least two blocks (I, II, ... ), each comprising at least two character sets (000, 001, ... ), are stored in the memory (23), the method further comprising the steps of: receiving a digital language code indicating the character set to be used from a block, and selecting one of the blocks, one of the blocks being selected by means of the user-selection means (41). 7. A method as claimed in claim 5, characterized in that the method further comprises the step of storing a preset in a non-volatile memory (7), a setting of the user- selection means (41) being stored per preset in the non- volatile memory (7).

Inventors: VAN GESTEL HENRICUS A W, VANDALE JOHAN M, VAN GESTEL, HENRICUS, A., W., VANDALE, JOHAN, M.
Applicants: KONINKL PHILIPS ELECTRONICS NV, KONINKLIJKE PHILIPS ELECTRONICS N.V.
Application year: 1999
Main classification: H04N7
IPC codes: G09G5, H04B1, H04N5, H04N7