Patent US5021882A successfully refreshed from Google Patents.
US5021882A
Expired / Lapsed
US
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Definition television systems
Assignee: Massachusetts Institute of Technology
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Filing: 1989-05-24
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Granted: 1991-06-04
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Expires: 2009-05-24
Abstract
Abstract A receiver-compatible EDTV system wherein enhancement information is adaptively modulated to suppress channel noise and is transmitted outside the usable picture area of a receiver compatible signal of the receiver compatible EDTV system.
Inventors
- 👤 William F. Schreiber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:07
CPC Classifications
H; H04; H04N; H04N19/00; H04N19/10; H04N19/169; H04N19/186; H04N11/00; H04N11/24; H04N11/28; H04N19/60; H04N19/61; H04N19/619; H04N19/63; H04N7/00; H04N7/04; H04N7/08
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
67 words
A receiver-compatible EDTV system comprising means for adaptively modulating an enhancement signal so as to suppress channel noise and means for transmitting the adaptively-modulated enhancement signal as part of a receiver-compatible signal and outside the usable picture area of the receiver-compatible EDTV system but within at least a portion of the usable picture area of an NTSC system, said receiver-compatible signal carrying an EDTV aspect ratio image.
Claim 2
Dependent Claim
67 words
A receiver-compatible EDTV system comprising means for adaptively modulating an enhancement signal so as to suppress channel noise and means for transmitting the adaptively-modulated enhancement signal as part of a receiver-compatible signal and outside the usable picture area of the receiver-compatible EDTV system but within at least a portion of the usable picture area of an NTSC system, said receiver-compatible signal carrying an EDTV aspect ratio image.
Claim 3
Dependent Claim
41 words
The system of claim 1 further comprising means for increasing effective bandwidth at the expense of signal-to-noise ratio by superimposing a reduced amplitude enhancement signal on a multilevel digital signal, said reduced-amplitude enhancement signal being derived from the adaptively-modulated enhancement signal.
Claim 4
Dependent Claim
57 words
The system of claim 1 further comprising a receiver compatible with said enhanced-definition television system, said receiver comprising compatible front-end circuitry for selecting and demodulating the received RF signal to produce a video signal, compatible processing circuitry for processing the video signal to produce display data, and display circuitry to display said data on a display device.
Claim 5
Dependent Claim
29 words
The system of claim 1 wherein the enhancement signal is placed within bar areas located at the top and/or bottom of the usable picture area of the NTSC system.
Claim 6
Dependent Claim
38 words
The system of claim 1 wherein said high frequency information lies outside a block of frequency space, said block having the dimensions of about 425 samples per width by 240 lines per height by 12 frames per second.
References Cited (Backward Citations)
GB505653A
Cited
US4268854A
Cited
US4268861A
Cited
US4551753A
Cited
US4551754A
Cited
US4707728A
Cited
US4628344A
Cited
GB2138238A
Cited
JPS60208191A
Cited
US4621287A
Cited
US4621286A
Cited
US4788692A
Cited
US4721998A
Cited
US4785348A
Cited
US4907087A
Cited
US4855811A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-06-03 | 1994-12-03 | 1995-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-03 | 1998-12-03 | 1999-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-03 | 2002-12-03 | 2003-06-04 | $7700.00 | Window Closed / Lapsed |