US4271409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for converting digital data into a video signal for displaying characters on a television receiver
Assignee: Philips North America LLC
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Filing: 1978-05-19
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Granted: 1981-06-02
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Expires: 1998-05-19
Abstract
Abstract Apparatus is described for converting the digital output of a microprocessor system into a video signal. The video signal is thereafter applied to a television receiver to cause objects described and controlled by a microprocessor system to be displayed on the television receiver. The apparatus is specifically used to provide an interface between a microprocessor controlled video game and a television monitor or receiver.
Inventors
- 👤 Paul D. Filliman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:00
CPC Classifications
G; G09; G09G; G09G1/00; G09G1/28; G09G1/285; A; A63; A63F; A63F13/00; A63F13/40; A63F2300/00; A63F2300/20; A63F2300/203
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
240 words
Apparatus for generating a video signal in a standard NTSC format from a digital signal source, said source providing a first group of binary words for indicating the red, green and blue signal components of a picture detail, and a second group of binary words for indicating the occurrence of a horizontal synchronization interval, vertical synchronization interval, a blanking interval, and a burst signal, comprising: (a) matrix means for converting said first group of binary words representing the red, green and blue components of said picture detail into a d.c. voltage, said d.c. voltage representing the luminance level of said picture detail; (b) a signal source for providing first and second signals at 3.58 mHz, said signals having a phase difference of 90°; (c) a first balanced modulator for receiving said first signal, said modulator having an output signal determined by said first group of binary words; (d) a second balanced modulator for receiving said second signal and controlling the magnitude of said second signal, said balanced modulator providing a signal having a magnitude proportionally controlled by said first group of binary words; (e) means for modifying said luminance signal when said digital signal source indicates a synchronization signal or a blanking signal are to occur; and (f) means for combining the output of said modulators and said matrix whereby a video signal is produced specifying the brightness and color of said picture detail in accordance with an NTSC format.
Claim 2
Dependent Claim
240 words
Apparatus for generating a video signal in a standard NTSC format from a digital signal source, said source providing a first group of binary words for indicating the red, green and blue signal components of a picture detail, and a second group of binary words for indicating the occurrence of a horizontal synchronization interval, vertical synchronization interval, a blanking interval, and a burst signal, comprising: (a) matrix means for converting said first group of binary words representing the red, green and blue components of said picture detail into a d.c. voltage, said d.c. voltage representing the luminance level of said picture detail; (b) a signal source for providing first and second signals at 3.58 mHz, said signals having a phase difference of 90°; (c) a first balanced modulator for receiving said first signal, said modulator having an output signal determined by said first group of binary words; (d) a second balanced modulator for receiving said second signal and controlling the magnitude of said second signal, said balanced modulator providing a signal having a magnitude proportionally controlled by said first group of binary words; (e) means for modifying said luminance signal when said digital signal source indicates a synchronization signal or a blanking signal are to occur; and (f) means for combining the output of said modulators and said matrix whereby a video signal is produced specifying the brightness and color of said picture detail in accordance with an NTSC format.
Claim 3
Dependent Claim
184 words
A digital to video interface for converting digital data specifying the color and brightness level of a horizontal line into a video signal for display on a video monitor comprising: (a) a source of digital data for specifying the red, blue and green components of a horizontally scanned line; (b) matrix means for converting data representing said red, blue and green components into a d.c. voltage level, said d.c. voltage level representing a luminance signal for said line; (c) a source of 3.58 mHz signal, said source providing first and second signals having a phase difference of 90°; (d) a first balanced modulator for receiving said first signal, said balanced modulator providing a differential output signal having a magnitude controllable by said digital data; (e) a second balanced modulator for receiving said second signal, said balanced modulator providing a differential output signal having a magnitude controllable by said digital data; and (f) means for combining said differential output signals with said luminance signal whereby a line of composite video signal is produced for specifying the color and brightness of a line of picture detail.
Claim 4
Dependent Claim
184 words
A digital to video interface for converting digital data specifying the color and brightness level of a horizontal line into a video signal for display on a video monitor comprising: (a) a source of digital data for specifying the red, blue and green components of a horizontally scanned line; (b) matrix means for converting data representing said red, blue and green components into a d.c. voltage level, said d.c. voltage level representing a luminance signal for said line; (c) a source of 3.58 mHz signal, said source providing first and second signals having a phase difference of 90°; (d) a first balanced modulator for receiving said first signal, said balanced modulator providing a differential output signal having a magnitude controllable by said digital data; (e) a second balanced modulator for receiving said second signal, said balanced modulator providing a differential output signal having a magnitude controllable by said digital data; and (f) means for combining said differential output signals with said luminance signal whereby a line of composite video signal is produced for specifying the color and brightness of a line of picture detail.
Claim 5
Dependent Claim
24 words
The apparatus of claim 2 further comprising means for adding a burst signal and horizontal synchronization signal to said line of composite video signals.
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) | 1984-06-01 | 1984-12-01 | 1985-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-01 | 1988-12-01 | 1989-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-01 | 1992-12-01 | 1993-06-02 | $7700.00 | Window Closed / Lapsed |