US5790113A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for loosely sychronizing closed free-running raster displays
Assignee: HearMe
•
Filing: 1996-09-12
•
Granted: 1998-08-04
•
Expires: 2016-09-12
Abstract
Abstract The present invention is a means and method for synchronizing closed free-running systems, such as graphics systems, with no external synchronization signals required. Video games and most computer display controllers are closed free-running systems. Because most such systems have the means to switch between an interlaced and non-interlaced operation, and because interlaced and non-interlaced modes have a relative timing variation, the timing between two or more such closed free-running systems can be synchronized. This method allows synchronization with an imprecise timing reference. The vertical display timing is the free-running oscillator and the interlaced/non-interlaced mode transition is used as the timing adjustment means. The actual arrival time of data in a communication medium connecting two systems being synchronized is used in relation to an expected arrival time to provide the clock reference.
Inventors
- 👤 Stephen G. Perlman
- 👤 Steven G. Roskowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:35
CPC Classifications
G; G09; G09G; G09G5/00; G09G5/12; H; H04; H04N; H04N5/00; H04N5/04; H04N5/06; H04N5/067; H04N5/073; H04N7/00; H04N7/01; G09G2310/00; G09G2310/02; G09G2310/0224
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
130 words
An apparatus for adjusting the timing of the display of frames in a raster display having an interlaced display mode and a non-interlaced display mode, said apparatus comprising: means for detecting a refresh cycle event in the raster display operating in one of said interlaced display mode and said non-interlaced display mode; means for receiving information indicative of a secondary timing event, said information being received from an external timing reference; means for comparing a time of occurrence of said refresh cycle event with said information indicative of said secondary timing event; and means for activating an alternate one of said interlaced display mode and said non-interlaced display mode in said raster display to synchronize the display of frames in said raster display in reference to said secondary timing event.
Claim 2
Independent Claim
130 words
An apparatus for adjusting the timing of the display of frames in a raster display having an interlaced display mode and a non-interlaced display mode, said apparatus comprising: means for detecting a refresh cycle event in the raster display operating in one of said interlaced display mode and said non-interlaced display mode; means for receiving information indicative of a secondary timing event, said information being received from an external timing reference; means for comparing a time of occurrence of said refresh cycle event with said information indicative of said secondary timing event; and means for activating an alternate one of said interlaced display mode and said non-interlaced display mode in said raster display to synchronize the display of frames in said raster display in reference to said secondary timing event.
Claim 3
Dependent Claim
17 words
The apparatus as claimed in claim 1 wherein said first raster display is an NTSC type display.
Claim 4
Dependent Claim
17 words
The apparatus as claimed in claim 1 wherein said first raster display is a PAL type display.
Claim 5
Dependent Claim
17 words
The apparatus as claimed in claim 1 wherein said first raster display is a SECAM type display.
Claim 6
Dependent Claim
17 words
The apparatus as claimed in claim 1 wherein said apparatus is coupled to a video game system.
Claim 7
Dependent Claim
29 words
The apparatus as claimed in claim 1 wherein said apparatus is coupled to a first video game system directly and coupled to a second video game system via modem.
Claim 8
Independent Claim
106 words
An apparatus for adjusting the timing of the display of frames in a raster display operating normally in a non-interlaced display mode, said apparatus comprising: means for detecting a refresh cycle event in a raster display; means for receiving information indicative of a secondary timing event, said information being received from an external timing reference; means for comparing a time of occurrence of said refresh cycle event with said information indicative of said secondary timing event; and means for periodically activating an interlaced display mode in said raster display to synchronize the display of frames in said raster display in reference to said secondary timing event.
Claim 9
Independent Claim
106 words
An apparatus for adjusting the timing of the display of frames in a raster display operating normally in a non-interlaced display mode, said apparatus comprising: means for detecting a refresh cycle event in a raster display; means for receiving information indicative of a secondary timing event, said information being received from an external timing reference; means for comparing a time of occurrence of said refresh cycle event with said information indicative of said secondary timing event; and means for periodically activating an interlaced display mode in said raster display to synchronize the display of frames in said raster display in reference to said secondary timing event.
Claim 10
Dependent Claim
17 words
The apparatus as claimed in claim 7 wherein said first raster display is an NTSC type display.
Claim 11
Dependent Claim
17 words
The apparatus as claimed in claim 7 wherein said first raster display is a PAL type display.
Claim 12
Dependent Claim
17 words
The apparatus as claimed in claim 7 wherein said first raster display is a SECAM type display.
Claim 13
Dependent Claim
17 words
The apparatus as claimed in claim 7 wherein said apparatus is coupled to a video game system.
Claim 14
Dependent Claim
29 words
The apparatus as claimed in claim 7 wherein said apparatus is coupled to a first video game system directly and coupled to a second video game system via modem.
Claim 15
Independent Claim
96 words
An apparatus for adjusting the timing of the display of frames in a raster display operating normally in an interlaced display mode, said apparatus comprising: means for detecting a refresh cycle event in a raster display; means for receiving information indicative of a secondary timing event, said information being received from an external timing reference; means for comparing a time of occurrence of said refresh cycle event with said information indicative of said secondary timing event; and means for periodically activiating a non-interlaced display mode in said raster display in reference to said secondary timing event.
Claim 16
Independent Claim
96 words
An apparatus for adjusting the timing of the display of frames in a raster display operating normally in an interlaced display mode, said apparatus comprising: means for detecting a refresh cycle event in a raster display; means for receiving information indicative of a secondary timing event, said information being received from an external timing reference; means for comparing a time of occurrence of said refresh cycle event with said information indicative of said secondary timing event; and means for periodically activiating a non-interlaced display mode in said raster display in reference to said secondary timing event.
Claim 17
Dependent Claim
17 words
The apparatus as claimed in claim 13 wherein said first raster display is an NTSC type display.
Claim 18
Dependent Claim
17 words
The apparatus as claimed in claim 13 wherein said first raster display is a PAL type display.
Claim 19
Dependent Claim
17 words
The apparatus as claimed in claim 13 wherein said first raster display is a SECAM type display.
Claim 20
Dependent Claim
17 words
The apparatus as claimed in claim 13 wherein said apparatus is coupled to a video game system.
Claim 21
Dependent Claim
29 words
The apparatus as claimed in claim 13 wherein said apparatus is coupled to a first video game system directly and coupled to a second video game system via modem.
Claim 22
Independent Claim
128 words
An apparatus for synchronizing raster displays, the raster displays being coupled by a data-communications means, said apparatus comprising: a first raster display; a means for sending signals from the first raster display; a second raster display, the second raster display capable of operation in a non-interlaced display mode and an interlaced display mode, the second raster display having a means for receiving signals, a means for changing the operational mode of the second raster display from non-interlaced display mode to interlaced display mode in response to a first signal sent from the first raster display; and a means for changing the operational mode of the second raster display from interlaced display mode to non-interlaced display mode in response to a second signal sent from the first raster display.
Claim 23
Independent Claim
128 words
An apparatus for synchronizing raster displays, the raster displays being coupled by a data-communications means, said apparatus comprising: a first raster display; a means for sending signals from the first raster display; a second raster display, the second raster display capable of operation in a non-interlaced display mode and an interlaced display mode, the second raster display having a means for receiving signals, a means for changing the operational mode of the second raster display from non-interlaced display mode to interlaced display mode in response to a first signal sent from the first raster display; and a means for changing the operational mode of the second raster display from interlaced display mode to non-interlaced display mode in response to a second signal sent from the first raster display.
Claim 24
Dependent Claim
22 words
The apparatus as set forth in claim 19 wherein the first raster display is capable of operation in a non-interlaced display mode.
Claim 25
Dependent Claim
22 words
The apparatus as set forth in claim 19 wherein the first raster display is capable of operation in an interlaced display mode.
Claim 26
Dependent Claim
26 words
The apparatus as set forth in claim 19 wherein the first raster display is capable of operation in a non-interlaced mode and an interlaced display mode.
Claim 27
Independent Claim
36 words
The apparatus as set forth in claims 19, 20, 21 or 22 further comprising a means for sending a signal from the second raster display, and the first raster display having a means for receiving signals.
References Cited (Backward Citations)
US4005265A
Cited
US4025951A
Cited
US4572509A
Cited
US4520477A
Cited
US4611228A
Cited
US4720708A
Cited
US4904990A
Cited
US4592546A
Cited
US5070479A
Cited
US4799635A
Cited
US4837626A
Cited
US4998199A
Cited
US4980897A
Cited
EP0402067A2
Cited
US5112051A
Cited
US5083800A
Cited
US5098110A
Cited
US5013038A
Cited
US5120076A
Cited
US5155768A
Cited
US5369444A
Cited
US5161803A
Cited
US5291189A
Cited
US5048831A
Cited
EP0481770A2
Cited
US5103446A
Cited
US5351088A
Cited
US5292125A
Cited
US5350176A
Cited
US5538255A
Cited
EP0571138A2
Cited
EP0571213A1
Cited
US5469183A
Cited
GB9323125D0
Cited
GB2272569A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-08-03 | 2002-02-02 | 2002-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-03 | 2006-02-02 | 2006-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-03 | 2010-02-02 | 2010-08-04 | $7700.00 | Window Closed / Lapsed |