US3781849A
Expired / Lapsed
US
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Method and apparatus for generating self contrasting character images
Assignee: CBS Broadcasting Inc
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Filing: 1972-03-20
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Granted: 1973-12-25
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Expires: 1992-03-20
Abstract
Abstract A subsystem of an apparatus that receives characterrepresentative signals and generates video control signals and keying control signals that are suitable for controlling a scanned display to present contrasting character images. A stroke generator means, responsive to the character-representative signals, generates a stroke of a character to be displayed. The stroke consists of a plurality of time sequential bits corresponding to a sequence of display events and a plurality of code bits that distinguish between contrasting portions of the sequence of display events. A decoding means is responsive to the time sequential bits and the code bits and generates keying control signals and video control signals that are suitable for controlling a scanned display to present contrasted images of characters to be displayed. In a preferred embodiment of the invention, the code bits are representative of the keying and video portions of the sequence of display events. The coding means produces signals that disable the generation of video signal during selected stroke portions, the code bits being determinative of which portions of the display event are to be disabled.
Inventors
- 👤 S Baron
- 👤 S Kreinik
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:01
CPC Classifications
G; G09; G09G; G09G5/00; G09G5/22; G09G5/24; G09G5/243
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
138 words
In an apparatus that receives character-representative signals and generates video control signals and keying control signals that are suitable for controlling a scanned display to present self-contrasting character images superimposed on a background, the combination comprising: stroke generator means responsive to said characterrepresentative signals for generating a stroke for each scanline of a character to be displayed, said stroke comprising a plurality of time sequential bits corresponding to a sequence of character display events and a plurality of code bits generated simultaneously with said time sequential bits for distinguishing between contrasting portions of the sequence of character display events; and decoding means responsive to said time sequential bits and said code bits for generating keying control signals and video control signals suitable for controlling the scanned display to present the self-contrasting images of the characters to be displayed.
Claim 2
Dependent Claim
138 words
In an apparatus that receives character-representative signals and generates video control signals and keying control signals that are suitable for controlling a scanned display to present self-contrasting character images superimposed on a background, the combination comprising: stroke generator means responsive to said characterrepresentative signals for generating a stroke for each scanline of a character to be displayed, said stroke comprising a plurality of time sequential bits corresponding to a sequence of character display events and a plurality of code bits generated simultaneously with said time sequential bits for distinguishing between contrasting portions of the sequence of character display events; and decoding means responsive to said time sequential bits and said code bits for generating keying control signals and video control signals suitable for controlling the scanned display to present the self-contrasting images of the characters to be displayed.
Claim 3
Dependent Claim
26 words
The combination as defined by claim 1 wherein said code bits are representative of the keying and video portions of the sequence of character display events.
Claim 4
Dependent Claim
31 words
The combination as defined by claim 2 wherein said decoding means includes horizontal delay means for receiving signals representative of said time sequential bits and generating delayed versions of said signals.
Claim 5
Dependent Claim
38 words
The combination as defined by claim 1 wherein said decoding means includes stroke portion sensing means for sensing various portions of signals represented by said time sequential bits and for generating different output signals during said various portions.
Claim 6
Dependent Claim
43 words
The combination as defined by claim 4 wherein said decoding means includes means responsive to the outputs of said stroke portion sensing means and to said code bits for producing signals that disable the generation of a video signal during selected stroke portions.
Claim 7
Dependent Claim
25 words
The combination as defined by claim 5 wherein said code bits are determinative of which portions of the character display events are to be disabled.
Claim 8
Dependent Claim
27 words
The combination as defined by claim 6 wherein said stroke portion sensing means senses even and odd portions of the signals representative of said time sequential bits.
Claim 9
Dependent Claim
146 words
In an apparatus that receives character-representative signals and display synchronizing signals and generates video control signals and keying control signals that are suitable for controlling a scanned display to present self-contrasting character images superimposed on a background, the combination comprising: stroke generator means responsive to said character-representative signals and said synchronizing signals for generating a stroke for each scanline of a character to be displayed, said stroke comprising a plurality of time sequeNtial bits corresponding to a sequence of character display events and first and second code bits generated simultaneously with said time sequential bits for distinguishing between contrasting portions of the sequence of character display events; and decoding means responsive to said time sequential bits and said code bits for generating keying control signals and video control signals suitable for controlling the scanned display to present the self-contrasting images of the characters to be displayed.
Claim 10
Dependent Claim
146 words
In an apparatus that receives character-representative signals and display synchronizing signals and generates video control signals and keying control signals that are suitable for controlling a scanned display to present self-contrasting character images superimposed on a background, the combination comprising: stroke generator means responsive to said character-representative signals and said synchronizing signals for generating a stroke for each scanline of a character to be displayed, said stroke comprising a plurality of time sequeNtial bits corresponding to a sequence of character display events and first and second code bits generated simultaneously with said time sequential bits for distinguishing between contrasting portions of the sequence of character display events; and decoding means responsive to said time sequential bits and said code bits for generating keying control signals and video control signals suitable for controlling the scanned display to present the self-contrasting images of the characters to be displayed.
Claim 11
Dependent Claim
46 words
The combination as defined by claim 8 wherein said decoding means includes stroke portion sensing means for sensing the odd and even portions of signals represented by the time sequential bits and for generating first and second output signals during said off and even portions respectively.
Claim 12
Dependent Claim
57 words
The combination as defined by claim 9 wherein said first code bit indicates that video is to be inhibited during the odd portions of the signals represented by the time sequential bits, and the second code bit indicates that video is to be inhibited during the even portions of the signals represented by the time sequential bits.
Claim 13
Dependent Claim
81 words
The combination as defined by claim 10 wherein said decoding means further includes a first gate which receives as inputs said first code bit and said first output signal and produces a first inhibit signal when its inputs are present simultaneously, and a second gate which receives as inputs said second code bit and said second output signal and produces a second inhibit signal when its inputs are present simultaneously, said first and second input signals being adapted to inhibit video.
Claim 14
Dependent Claim
31 words
The combination as defined by claim 11 wherein said decoding means includes horizontal delay means for receiving signals representative of said time sequential bits and generating delayed versions of said signals.
Claim 15
Dependent Claim
55 words
The combination as defined by claim 12 wherein said decoding means includes a keying gate and a video gate, said keying gate receiving the signals representative of the time sequential bits and all delayed versions thereof, and said video gate receiving one of the delayed versions of the signals representative of the time sequential bits.
Claim 16
Dependent Claim
20 words
The combination as defined by claim 13 wherein said video gate receives as inputs said first and second input signals.
Claim 17
Dependent Claim
23 words
The combination as defined by claim 14 wherein said keying gate is an OR gate and said video gate is an AND gate.
Claim 18
Dependent Claim
73 words
The combination as defined by claim 14 wherein said stroke generator means generates a third code bit for each character to be displayed and wherein said decoding means further includes a third gate which receives said first and second output signals and a fourth gate which receives said third code bit and the output of said third gate, the output of said fourth gate being received as an input by said keying gate.
Claim 19
Dependent Claim
23 words
The combination as defined by claim 16 wherein said third gate is an OR gate and said fourth gate is an AND gate.
Claim 20
Dependent Claim
23 words
The combination as defined by claim 17 wherein said keying gate is an OR gate and said video gate is an AND gate.
Claim 21
Independent Claim
123 words
A method of receiving character-representative signals and generating video control signals and keying control signals that are suitable for controlling a scanned display to present self-contrasting character images, comprising the steps of: a. generating a stroke for each scanline of a character to be displayed, said stroke comprising a plurality of time sequential bits corresponding to a sequence of character display events and a simultaneously generated plurality of code bits that distinguish between contrasting portions of the sequence of character display events; b. generating said keying control signals from said time sequential bits; and c. generating said video control signals from selected portions of said time sequential bits, said code bits being determinative of which portions of said time sequential bits are selected.
Claim 22
Independent Claim
123 words
A method of receiving character-representative signals and generating video control signals and keying control signals that are suitable for controlling a scanned display to present self-contrasting character images, comprising the steps of: a. generating a stroke for each scanline of a character to be displayed, said stroke comprising a plurality of time sequential bits corresponding to a sequence of character display events and a simultaneously generated plurality of code bits that distinguish between contrasting portions of the sequence of character display events; b. generating said keying control signals from said time sequential bits; and c. generating said video control signals from selected portions of said time sequential bits, said code bits being determinative of which portions of said time sequential bits are selected.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |