US4405830A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Elimination of display blanks resulting from the use of character attribute codes in a videotex type system
Assignee: Post Office
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Filing: 1981-07-01
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Granted: 1983-09-20
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Expires: 2001-07-01
Abstract
Abstract A data transmission of the videotex type in which coded information can be transmitted from a central information store to a plurality of terminals. The coded information includes groups of bits representing characters and groups of bits representing control codes. In the transmission technique used in the system a character attribute can be represented by a display control code which is transmitted in association with a cursor backspace code. By using this technique characters of different attributes can be displayed without a space being required between the characters on the display.
Inventors
- 👤 Robert A. L. Foster
- 👤 Geoffrey H. L. Childs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 01:52
CPC Classifications
G; G09; G09G; G09G1/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
185 words
A videotex type data transmission system comprising: central information processing and storage means for storing and retrieving coded digital information signals representing display characters and character attributes thereof; a plurality of remotely situated data displaying terminals, some having split memory character oriented attribute display systems and others having string oriented attribute display systems; and digital data communication means connecting said central information processing and storage means situated at a central site to said plurality of remotely situated data displaying terminals for selective serial transmission of said coded information signals to said remote terminals; said central data processing means effecting transmission of a cursor backspace code substantially adjacent a transmitted display control code representing a display character attribute unless the just previous display character is to be followed by a display space thereby permitting successful compatible videotex transmission of the same said coded information signals to the remote terminals having split memory character oriented attribute display systems as well as to the remote terminals having a string oriented attribute display system without requiring a displayed space between changes in displayed character attributes on any remote terminal.
Claim 2
Dependent Claim
185 words
A videotex type data transmission system comprising: central information processing and storage means for storing and retrieving coded digital information signals representing display characters and character attributes thereof; a plurality of remotely situated data displaying terminals, some having split memory character oriented attribute display systems and others having string oriented attribute display systems; and digital data communication means connecting said central information processing and storage means situated at a central site to said plurality of remotely situated data displaying terminals for selective serial transmission of said coded information signals to said remote terminals; said central data processing means effecting transmission of a cursor backspace code substantially adjacent a transmitted display control code representing a display character attribute unless the just previous display character is to be followed by a display space thereby permitting successful compatible videotex transmission of the same said coded information signals to the remote terminals having split memory character oriented attribute display systems as well as to the remote terminals having a string oriented attribute display system without requiring a displayed space between changes in displayed character attributes on any remote terminal.
Claim 3
Dependent Claim
42 words
A videotex type data transmission system as in claim 1 wherein when said central data processing means associates a plurality of control codes with a particular character display location, a cursor backspace code is transmitted in association with each such control code.
Claim 4
Dependent Claim
19 words
A videotex type data transmission system as in claim 1 wherein said cursor backspace code follows said control code.
Claim 5
Dependent Claim
19 words
A videotex type data transmission system as in claim 1 wherein said cursor backspace code precedes said control code.
Claim 6
Dependent Claim
22 words
A videotex type data transmission system as in claim 1 wherein said digital data communication means comprises a network of telephone lines.
Claim 7
Independent Claim
140 words
A method of serially transmitting in a videotex type data transmission system, coded information representing characters and character attributes between a central information store and a plurality of remotely situated data displaying terminals, some having split memory character oriented attribute display systems and others having string oriented attribute display systems, said method comprising the steps of: transmitting a cursor backspace code substantially adjacent a transmitted display control code representing a display character attribute unless the just previous display character is to be followed by a display space thereby permitting successful compatible videotex transmission of the same coded information signals to the remote terminals having split memory character oriented attribute display systems as well as to the remote terminals having a string oriented attribute display system without requiring a displayed space between changes in displayed character attributes on any remote terminal.
Claim 8
Independent Claim
140 words
A method of serially transmitting in a videotex type data transmission system, coded information representing characters and character attributes between a central information store and a plurality of remotely situated data displaying terminals, some having split memory character oriented attribute display systems and others having string oriented attribute display systems, said method comprising the steps of: transmitting a cursor backspace code substantially adjacent a transmitted display control code representing a display character attribute unless the just previous display character is to be followed by a display space thereby permitting successful compatible videotex transmission of the same coded information signals to the remote terminals having split memory character oriented attribute display systems as well as to the remote terminals having a string oriented attribute display system without requiring a displayed space between changes in displayed character attributes on any remote terminal.
Claim 9
Dependent Claim
15 words
A method as in claim 6 wherein said cursor backspace code follows the control code.
Claim 10
Dependent Claim
15 words
A method as in claim 6 wherein said cursor backspace code precedes the control code.
Claim 11
Dependent Claim
34 words
A method as in claim 6 wherein when a plurality of control codes are associated with a particular display character location, a cursor backspace code is transmitted in association with each such control code.
References Cited (Backward Citations)
US4297693A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-09-19 | 1987-03-21 | 1987-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-19 | 1991-03-21 | 1991-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-19 | 1995-03-21 | 1995-09-20 | $7700.00 | Window Closed / Lapsed |