Patent US4736240A successfully refreshed from Google Patents.
US4736240A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Analog to digital video adapter
Assignee: Dell USA LP
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Filing: 1986-04-28
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Granted: 1988-04-05
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Expires: 2006-04-28
Abstract
Abstract The invention processes a National Television System Committee (NTSC) standard video signal to allow a digital, transistor to transistor logic (TTL), 8 color, separate red, green, and blue (RGB) video, color monitor to be used to display television (TV) images. The infinite colors necessary for TV are produced on an 8 color TTL monitor through pulse width modulation. Thus, the width of the TTL video pulse to each color input of the monitor is proportional to the brightness required that is contained in the NTSC signal.
Inventors
- 👤 James V. Samuels
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:59
CPC Classifications
G; G09; G09G; G09G1/00; G09G1/28; G09G1/285; H; H04; H04N; H04N9/00; H04N9/64; H04N9/641
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
140 words
An analog to digital adapter which converts standard broadcast video signals to TTL signals for driving an 8 color monitor to display TV and TV-like images comprising: a color decoder circuit that separates the red, green, and blue information from the standard broadcast video signals into three analog signals, a sync separator circuit that detects th horizontal and vertical synchronization signals from the video signals, a ramp generator that is synchronized to the video signals, three comparator sections which compare the ramp signal to each red, green, and blue analog signal, each section outputting a TTL signal whose pulsewidth is proportional to the analog signal amplitude and is sampled at the ramp signals frequency, whereby the outputs of the comparator sections drive an eight color TTL monitor to display as many colors as are present in the broadcast video signal.
Claim 2
Dependent Claim
140 words
An analog to digital adapter which converts standard broadcast video signals to TTL signals for driving an 8 color monitor to display TV and TV-like images comprising: a color decoder circuit that separates the red, green, and blue information from the standard broadcast video signals into three analog signals, a sync separator circuit that detects th horizontal and vertical synchronization signals from the video signals, a ramp generator that is synchronized to the video signals, three comparator sections which compare the ramp signal to each red, green, and blue analog signal, each section outputting a TTL signal whose pulsewidth is proportional to the analog signal amplitude and is sampled at the ramp signals frequency, whereby the outputs of the comparator sections drive an eight color TTL monitor to display as many colors as are present in the broadcast video signal.
Claim 3
Dependent Claim
42 words
An analog to digital video adapter described in claim 1, wherein the outputs drive any kind of TTL monitor such as monochrome monitors as well as any TTL color monitor regardless of the amount of colors the monitor is able to display.
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) | 1991-04-05 | 1991-10-05 | 1992-04-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-05 | 1995-10-05 | 1996-04-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-05 | 1999-10-05 | 2000-04-05 | $7700.00 | Window Closed / Lapsed |