Television – Format – Including additional information
Reexamination Certificate
2000-03-27
2001-05-08
Kostak, Victor R. (Department: 2611)
Television
Format
Including additional information
C348S553000
Reexamination Certificate
active
06229572
ABSTRACT:
BACKGROUND
There have been attempts in the past to superimpose data on a video signal. The most common approach is to insert data during the vertical blanking interval, such as in the generation of closed captioning signals. Another approach has been to place the data on the visible portion of the video signal. One advantage of the latter approach is that it may be possible to detect the data optically as well as electrically.
An example of the optical-detection approach is disclosed in Broughton et al. Pat. No. 4,807,031. The basic technique disclosed in this patent is to represent data by raising and lowering the luminance of successive horizontal lines within some designated viewing area. Because the average luminance of the two adjacent lines remains the same, the effect is not perceptible to the eye, but sensing of the alternate raising and lowering of the luminance by an appropriate receiver allows the data to be detected. As described in the Broughton et al. patent, the technique is equivalent to superimposing on the video signal a subcarrier frequency of 7.867 kHz, which can be detected by appropriate filtering. Broughton et al. also teach how to determine which fields should have data superimposed on them. For example, fields that are too white or too black are not appropriate for the insertion of data.
It is a general object of our invention to insert data on the visible portion of a video signal by changing the luminance of paired lines in opposite directions, but to do so in a manner that allows for a much higher data rate and the detection of the data in a much more accurate manner than has been possible in the prior art.
As used herein, the term video signal applies to any representation of the standard NTSC, PAL or SECAM signals in common use for video transmission including the analog form, directly digitized numerical representations, CCIR 601/656 standards-based digital representations, computer representations such as RGB or YUV, or other digital representations that are simply numerically converted from the directly digitized representation of standard video. (Encoding and decoding from any digitized form is contemplated as long as it can be determined how the signal was digitized and that information is not lost after digitization.)
SUMMARY OF THE INVENTION
Data is transmitted in the form of groups of data bits called symbols. Each symbol has associated with it one of a predetermined number of longer sequences of “chips” called PN sequences. The PN sequence transmitted for any symbol is divided into a multiplicity of lines of chips. Each line of chips is transmitted together with its inverse, in pair-wise fashion, by embedding them in respective pairs of line scans of the video signal. For example, each symbol representing 4 data bits may have associated with it one of 16 PN sequences of 80 chips each. Any such PN sequence that is to be superimposed on the video signal is divided into 4 lines of 20 chips each. Each line of chips is transmitted in its normal form and with its inverse, so that 8 lines of 20 chips each are added to or subtracted from respective line scans of the video signal.
Received pairs of line scans are operated upon to extract the 20 chips that they represent. This is done by subtracting one line scan from the other in order to minimize the effect of the video, and by integrating the difference signal for the duration of each chip. Because each chip in the original PN sequence is added to one line scan and subtracted from the other, when one line scan is subtracted from the other not only is the video effect minimized, but the magnitude of the chip amplitude is doubled. After all 80 chip pairs are processed in this way to derive 80 “integrated chip values,” the received code is correlated with each of the 16 possible PN sequences for a best match. The symbol that was transmitted is deemed to be that one whose PN sequence has the highest correlation with the received code.
REFERENCES:
patent: 3493674 (1970-02-01), Hougton
patent: 3728480 (1973-04-01), Baer
patent: 3737566 (1973-06-01), Baer et al.
patent: 3777410 (1973-12-01), Robinson
patent: 3842196 (1974-10-01), Loughlin
patent: 3900887 (1975-08-01), Soga et al.
patent: 3984624 (1976-10-01), Waggener
patent: 3993861 (1976-11-01), Baer
patent: 4186413 (1980-01-01), Mortimer
patent: 4206557 (1980-06-01), Swinton
patent: 4218697 (1980-08-01), Leventer
patent: 4329684 (1982-05-01), Monteath et al.
patent: 4368456 (1983-01-01), Degoulet et al.
patent: 4599644 (1986-07-01), Fischer
patent: 4608601 (1986-08-01), Shreck et al.
patent: 4729563 (1988-03-01), Yokoi
patent: 4807031 (1989-02-01), Broughton et al.
patent: 4969041 (1990-11-01), O'Grady et al.
patent: 5200822 (1993-04-01), Bronfin et al.
patent: 5243423 (1993-09-01), DeJean et al.
patent: 5327237 (1994-07-01), Gerdes et al.
patent: 5387941 (1995-02-01), Montgomery
patent: 5404160 (1995-04-01), Schober et al.
patent: 5557333 (1996-09-01), Jungo et al.
patent: 5557334 (1996-09-01), Legate
patent: 5559559 (1996-09-01), Jungo et al.
patent: 5663766 (1997-09-01), Sizer, II
patent: 5666168 (1997-09-01), Montgomery
patent: 5767896 (1998-09-01), Nemirofsky
“A Novel TV Add-On Data Communication System” Patrick J. King, Hazeltine Research, Inc. Chicago, ILL 60639.
Chupp Christopher Eric
Ciardullo Daniel Andrew
Kosbar Kurt Louis
Gottlieb Rackman & Reisman P.C.
Koplar Interactive International, LLC
Kostak Victor R.
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