GB2192770A

GB2192770A - Selecting pages for display

Info

Publication number: GB2192770A
Application number: GB08715293A
Authority: GB
Inventors: Roberto Dini; Attilio Farina
Original assignee: Sisvel SpA
Current assignee: Sisvel SpA
Priority date: 1986-06-30
Filing date: 1987-06-30
Publication date: 1988-01-20
Anticipated expiration: 2007-06-30
Also published as: GB8715293D0; IT8667521A0; GB2192770B; IT1203580B

Abstract

A teletext decoder has a keyboard 1 for controlling and selecting teletext pages to be displayed by a display unit 6. A memory 3 stores a sequence of user-selected page numbers supplied via the keyboard, for instance while viewing index pages. The stored page numbers are then recalled by operating the keyboard to allow the selected pages to be display on a television display 6. A page memory 5 stores the page selected for display and may also store the subsequent page in the sequence for display so as to reduce or eliminate the waiting time. <??>Page numbers may be selected either directly using the keyboard or by means of a cursor on the index pages, the cursor being controlled from the keyboard. <IMAGE>

Description

SPECIFICATION Apparatus for selecting pages for display The present invention relates to an apparatus for selecting data pages for display, for instance in the form of a receiver for a system of data transmission supplying a plurality of pages, each one selectable by a user from among all those receivable by sending to the receiver a sequence of numbers which specifies the chosen page, comprising a memory of pages, a page display, command means including a plurality of keys for actuation by the user to generate command signals, control means for generating in response to the command signals a sequence of numbers, and a decoder controlled by the control means and arranged to receive, select, process and reproduce the data pages when the sequence of numbers is received.

It is known that, in many European countries, including Italy, there are in operation systems (generally known under the Engiish name "teletext", and more specifically called in Italy "televideo" and in Federal Republic of Germany "Videotext") which allow the transmission, together with normal television signals, of additional data, inserted in the video signal (in the form of digitally coded signals) during some of the free horizontal lines in the vertical flyback time. The coded signals, on user command, are decoded by a suitable decoding circuit, of known type, normally implemented by means of integrated monolithic circuitry, included in the television set, so that any one of the transmitted data pages, containing texts or graphics, may be reproduced on the television screen.

Normally a few hundreds of pages are transmitted, arranged in groups according to the topics (for instance: last news: pages 110-125, sport: pages 150-162, politics: pages 210-222, games: pages 315-345, etc.); in the first page (page O) is contained the main index of contents and in subsequent pages the subindices for any topic, with the relevant page numbers.

With the early decoders the user was compelled, any time he wanted to see a certain page, to press three numbered keys in sequence, in order to obtain the three digit number of the wanted page. Moreover, whenever the user wanted to change the page, even to the next one, he was again compelled to press three keys to obtain the new page number, and often also was obliged to recall first the index and/or the subindex page in order to find the desired page number.

Of course this is rather troublesome and if an error occurs, i.e. if the wrong key is depressed, the user is always compelled first to complete the digit triplet and then press again the three correct keys. This is the reason why methods have been proposed in order to ease the user manoeuvre. For instance the Italian patent application N. 682221-A/83, filed on 22/11/1983 by Indesit S.p.A. describes a teletext signal receiver comprising memory means for storing the number of the displayed page, and control means allowing the user to recall and reproduce, by means of the actuation of only one key, the next or the preceding page in respect of the reproduced one.

Other types of receivers have also been proposed (e.g. based on the philips decoder 5230+5240 or the l.T.T. decoder TPU 2700), which comprise memory means for storing at the same time a plurality of data pages (for instance four to eight pages, normally subsequent pages) so that it is possible to reproduce them immediately under user command. Such receivers with a memory for storing the contents of a plurality of pages are of course more expensive, and also intrinsically tied to a predetermined number of programmable pages (four or eight).

As a consequence, even with these second generation receivers, the problem of an easy selection of a certain number of non consecutive pages, without consulting again the main index and/or the subindices, is not solved. In fact, if the user is interested in sport news, located in pages 150-162, and the cooking recipes, located in pages 400-415, even with the system described in the above cited Italian patent application, the user is compelled to consult again at least once the index, or to write down some page numbers for the cooking recipes. With the other system, the user cannot program more than eight pages although having an eight times greater memory.

According to a first aspect of the invention, there is provided an apparatus as defined in the appended Claim 1.

According to second, third and fourth aspects of the invention, there is provided receivers as defined in the appended Claims 5, 7 and 9, respectively.

Preferred embodiments of the invention are defined in the other appended claims.

It is thus possible to provide a receiver for a teletext transmission system of minimal cost, which allows the user easily to reproduce on the screen a sequence of numerous not necessarily consecutive data pages, without having to consult again the main index and/or the subindices.

The invention will be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a block diagram of a teletext signal receiver constituting a preferred embodiment of the invention; Figure 2 shows schematically a command unit of the receiver of Figure 1; and Figure 3 shows a flow diagram of the operation of a control unit of the receiver of Figure 1.

In Figure 1, reference numeral 1 indicates a command unit, numeral 2 a control unit, and numeral 3 a readwrite memory (preferably of the type generally called RAM [Random Access Memory), with eight bit addresses (Byte Wide), for instance a 64x8=512 bit memory, where the numbers for 21 pages could be stored. Numeral 4 indicates a Teletext decoder, numeral 5 a page memory (preferably a two page memory), numeral 6 a display system for the selected page content, and numeral 7 an additional display for showing the page number. Numeral 8 indicates a terminal where the video frequency Teletext signal is available.

The command unit 1 may be of a known type, for instance the keyboard of a remote control device, and provides, beyond the usual numbered keys 0-9 and other normally used keys for receiver control, at least two additional keys in order to store and recall the page numbers. In Figure 2, which schematically represents the keyboard of a suitable command unit, such additional keys are labelled with letters "M" and "E", for "memorize" and "execute". The control unit 2 will be described hereinafter.

The decoder 4, the page memory 5 and the display 6 may be of known type normally used in known Teletext receivers. The display 6 is normally represented by the television set cathode my tube.

The display 7 may be a known three digit seven segment LED display. Figure 3 shows the logical flow of the logic blocks of the control unit 2. The control unit may be implemented by means of either wired logic blocks or by means of a microprocessor (programmed logic). The two methods are equivalent in respect of operation.

Block 10 is the start of operation block and block 11 is the block which verifies whether the "M" key of the command unit 1 has been depressed. In checking blocks, in Figure 3, the bottom output corresponds to the "YES" answer, the lateral output corresponds to the "NO" answer. Therefore if the answer is "YES", i.e. if the "M" key has been depressed, the block 12 enables the memory 3 to be written ("Write"), zeroes a first address counter "A" and passes the control to the next block 13. In the contrary case, control is returned to the block 11.

Block 13 performs several operations which, for the sake of clarity, have been shown aside in blocks numbered from 22 to 27.

Block 22 increments counter "N" by one and block 23 verifies whether on command unit 1 a numbered key has been depressed. In the affirmative case control is passed to next block 24; in the negative case control returns to the block 23.

Block 24 sends the number of the depressed key to display 7, where it is displayed. Block 25 sends the same number, suitably coded, to the A+N address of the memory 3, where it is stored.

Block 26 verifies whether counter N has reached the number three, i.e. verifies whether the three digit page number has been completed. In the affirmative case control passes to next block 27; in the contrary case control returns to the block 22.

Block 27 increments counter A by three and passes control to block 14.

Block 14 verifies whether the "E", key has been depressed. In the affirmative case control passes to next block 15; in the negative case control returns to the block 12.

Block 15 decrements the A address counter by three, enables memory 3 to be read ("READ") and zeroes the N counter.

Block 16 increments the N counter by one and block 17 recalls from memory 3 the number stored at address A+N and sends it to decoder 4. Block 18 verifies whether the N counter has reached the number three. In the affirmative case control passes to next block 19; in the negative case control returns to the block 16.

Block 19 verifies whether the A counter has reached the number zero. In the affirmative case control passes to block 21; in the negative case control passes to next block 20; block 20 verifies whether the "E" key has been depressed. In the affirmative case control returns to the block 15; in the negative case the control returns to the block 20.

Block 21 ends the control unit operation for the present cycle; control returns to the starting block 10 eventually to start again a new operation cycle.

The user can, while consulting the main index or the subindices, store the numbers of the pages he would like to see, depressing first the "M" key and then so many triplets of digits as are the relevant pages. The display 7 shows for checking purposes the numbers the user is depressing one after the other. It is important to note that the user can do all this without starting the search for the indicated page as in the other known receivers, which as a consequence oblige the user, after each page selection, to recall the index page in order to store the number of the next page to be shown. Each time the user depresses the "E" key, one of the selected pages, whose numbers are stored in the memory 3, will be displayed. As soon as the stored numbers are over, the system comes back to the start of the cycle, ready for a new operation.

The receiver of Teletext transmissions aids the user in selecting the transmitted data pages, while featuring a minor cost in respect of other known solutions (four or eight page memory). In fact a memory greater than onepage-memory is not needed and, even if it is desired to make the task less difficult for the user, avoiding the wait time, only a two-pagememory is really needed. As the sequence of the pages to be displayed is already stored, the decoder may simply store the next-to-be displayed page, while the user is gazing at the actually displayed page.

Various modifications may be made within the scope of the invention. For example, it is possible to arrange the control unit 2 so as to use the same page display 6 in order to allow the user to select the pages to be stored.

More precisely, if the command unit 1 is pro vided with up-down arrow keys, the control unit 2 may implement a marker or "cursor" on the index page reproduced on the display 6 (for instance making the first digit of the page number in the index flash). The user, with the arrows, instead of pressing the three page number digits, may move the cursor up or down to the number of the desired page, and then press the "M" key. The control unit may then read directly in the page memory 5 the three page number digits which follow the cursor and may store them in the memory 3.

)All the rest will then proceed as in the em bodiment described. According to this varia tion, the selection is still easier for the user.

Instead of two up-down keys, four arrow keys may be provided (up-down and left-right arrows), so that the cursor may be exactly located on the first digit of the desired page number.

Also an intermediate method between the two described to store the page numbers may be implemented. A third special key may be provided, e.g. marked "S", and the logic of the control unit arranged so that the user can, after entering the write mode by means of the "M" key, select by means 6f the up-down keys the page number next or prior to that of the page displayed. The selected number ap pears on the display 7. Each time the up key is depressed the number is incremented by one and each time the down key is depressed the number is decremented by one (of course the page actually displayed on the display 6 remains unchanged). The user may store the number displayed on the display 7 in the memory 3 by depressing the "S" key. Also in this case all the rest will then proceed as in the embodiment described.

Moreover as normally the decoder 4 in cludes a microprocessor, another variation to the described receiver may be implemented by integrating the control unit 2 together with the decoder 4 in only one operating unit, con trolled by only one microprocessor, with a clear saving of means and costs.

Claims

1. An apparatus for selecting pages of data from a data communication system for dis play, comprising first manually operable means for supplying codes for identifying selected pages, a memory for storing the codes sup plied by the manually operable means, and second manually operable means for selecting one of the stored codes to control display of the corresponding selected page of data.

2. An apparatus as claimed in Claim 1, in which the first and second manually operable means comprise a keyboard and decoder.

3. An apparatus as claimed in Claim 1 or 2, comprising a data memory for storing the selected page of data.

4. An apparatus as claimed in Claim 3, comprising a further memory for storing a further page of data to be displayed subsequent to the selected page of data.

5. A receiver for a system of data transmission supplying a plurality of pages, each one selectable by a user from among all those receivable by sending to the receiver a sequence of numbers which specifies the chosen page, comprising a memory of pages, a page display, command means including a plurality of keys for actuation by the user to generate command signals, control means for generating in response to the command signals a sequence of numbers, a decoder controlled by the control means and arranged to receive, select, process and reproduce the data pages when the sequence of numbers is received, and memory means, the control means being arranged to prepare, in response to a first signal from the command means, to store in the memory means a sequence of numbers of data pages, the control means in response to a second signal from the command means being arranged to prepare to recall from the memory means the sequence of numbers of data pages and to supply the sequence to the decoder in order to obtain sequential reproduction of the data pages corresponding to the numbers in the sequence, the memory of pages containing two data pages, the control means, in response to the first receipt of the second signal from the command means being arranged to send to the decoder two triplets of consecutive digits stored in the memory means, the decoder being arranged to provide for selecting, storing and displaying on the display the page corresponding to the first triplet of digits and for selecting and storing in the second page of the page memory the page specified by the second triplet of digits so that, when a further second signal is received, the displaying of the subsequent stored page in the stored sequence is substantially immediate.

6. A receiver as claimed in Claim 5, in which the control means in response to the first signal from the command means is arranged to prepare to receive from the command means a sequence of digit triplets and to store the sequence of digit triplets in the memory means.

7. A receiver for a system of data transmission supplying a plurality of pages, each one selectable by the user from all those receiva ble by sending to the receiver a sequence of numbers which specifies the chosen page, comprising a memory of pages, a page dis play, command means including a plurality of keys for actuation by the user to generate command signals, control means for generat ing in response to the command signals a sequence of numbers, a decoder controlled by the control means and arranged to receive, select, process and reproduce the data pages when the sequence of numbers is received, and memory means, the control means being arranged to prepare, in response to a first signal from the command means, to store in the memory means a sequence of numbers of data pages, the control means, in response to a second signal from the command means being arranged to prepare to recall from the memory means the sequence of numbers of data pages and to supply the sequence, the control means being arranged not to change the page displayed on the display during reception of the sequence of numbers of data pages from the command means and during the storing of the sequence in the memory means.

8. A receiver as claimed in Claim 7, in which the command means comprise two keys marked with arrows, the control means being arranged, when the first signal is received, to prepare to display on a three digit display the number of the page displayed on the page display, to increment by one the page number each time one ofthe two arrow keys is depressed and to decrement the page number by one each time the other of the two arrow keys is depressed, and to store in the memory means the number displayed on three digit display each time a third signal is received from the command means.

9. A receiver for a system of data transmission supplying a plurality of pages, each one selectable by the user from among all those receivable by sending to the receiver a sequence of numbers which specifies the chosen page, comprising command means including a plurality of keys for actuation by the user to generate command signals, control means for generating in response to the command signals a sequence of numbers, a decoder controlled by the control means and arranged to receive, select, process and reproduce the data pages when the sequence of numbers is received, a page memory, a page display, and memory means, the control means being arranged to prepare, in response to a first signal from the command means, to display on the page display a marker or cursor to prepare to move the marker in response to commands received from the command means, and to store in the memory means a sequence of digit triplets,-read one after the other from the page memory as selected by the marker.

10. A receiver as claimed in Claim 9, in which the marker is implemented by making a character of the page displayed on the page display flash.

11. A receiver as claimed in Claim 9 or 10, in which the command means comprise two or four keys marked with arrows and the control means is arranged to move the marker each time one of the arrow keys of the command means is depressed.

12. A receiver as claimed in any one of Claims 7 to 11, comprising a pages memory and a page display, the pages memory being arranged to contain two data pages, the control means, in response to the second signal from the command means, being arranged to send to the decoder two subsequent digit triplets, stored in the memory means, the decoder being arranged to provide for selecting, storing and displaying on the display the page corresponding to the first one of the digit triplets and for selecting and storing in the second page of the two pages memory the page specified by the second digit triplet so that, when a further second signal is received, the displaying of the next page of the stored sequence is substantially immediate.

13. A receiver as claimed in any one of Claims 5 to 12, in which the control means is arranged, in response to each second signal from the command means, to send to the decoder, in order to obtain the selection and the sequential reproduction of the data pages corresponding to the numbers in the sequence, a digit triplet stored in the memory means, and to increment the addresses so that the triplet sequence corresponds to the stored one.

14. A receiver as claimed in any one of Claims 5 to 13, in which the control unit is implemented by means of wired logic.

15. A receiver as claimed in any one of Claims 5 to 13, in which the control unit is implemented by means of programmed logic and includes a microprocessor.

16. A receiver as claimed in Claim 12, in which the control unit is integrated together with the decoder and both are controlled by one microprocessor.

17. A receiver for a system of data transmission, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

18. A television receiver including an apparatus as claimed in any one of Claims 1 to 4 or a receiver as claimed in any one of Claims 5 to 17.