EP0609934A2
Expired / Lapsed
EP
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Television receiver including a teletext decoder
Assignee: Koninklijke Philips NV
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Filing: 1994-01-25
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Granted: —
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Expires: 2014-01-25
Abstract
Abstract The receiver is adapted to signalize that a request teletext has been changed or not changed with respect to the previous consultation of the relevant page. To this end the receiver forms a checkword upon reception of a teletext page, which checkword is representative of the contents of the page, and compares this with the checkword stored upon previous display of said page.
Inventors
- 👤 Rogatus Hubertus Hemanus Wester
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 04:35
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/08; H04N7/087; H04N7/088; H04N7/0882
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
93 words
A television receiver including a teletext decoder (4) for receiving and displaying teletext pages, characterized in that the receiver comprises: - means (13) for forming a checkword upon reception of a teletext page from the data codes constituting the contents of said page; - means (12) for storing the checkword upon display of a received teletext page in a memory location associated with said page; - means (9) for comparing the checkword formed for the received page with the checkword stored for said page and for generating an attention signal in conformity therewith.
Claim 2
Dependent Claim
23 words
A television receiver as claimed in Claim 1, characterized in that the checkword is formed by a modulo-N sum of the data codes.
Claim 3
Dependent Claim
24 words
A television receiver as claimed in Claim 1, characterized in that the checkword is formed by a cyclic redundancy check of the data codes.
Claim 4
Dependent Claim
22 words
A television receiver as claimed in Claim 1, characterized in that the checkword is formed by a checkword transmitted with the page.
Claim 5
Dependent Claim
31 words
A television receiver as claimed in Claim 4, characterized in that the checkword is formed by an ordinal number which is modified at the transmitter end when the page is modified.
Claim 6
Dependent Claim
42 words
A television receiver as claimed in Claim 1, characterized in that the receiver further comprises means ensuring that, upon reception of predetermined teletext pages, the checkword formed upon said reception is stored in a further memory location associated with the received page.
Claim 7
Dependent Claim
32 words
A transmitter for transmitting teletext pages, characterized in that the transmitter is adapted to form an ordinal number for each page and to change said number upon modification of the page contents.
References Cited (Backward Citations)
No citation records indexed.
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