Television – Nonpictorial data packet in television format – Data separation or detection
Reexamination Certificate
1997-05-05
2001-05-29
Eisenzopf, Reinhard J. (Department: 2614)
Television
Nonpictorial data packet in television format
Data separation or detection
C348S468000, C348S473000, C348S478000, C348S461000
Reexamination Certificate
active
06239843
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to decoding signals, and more particularly, to methods and apparatus for decoding teletext and/or closed caption data embedded within signals such as video signals.
2. Description of the Related Art
Although watching television has been the national pastime of the United States and other countries for many years, the computer revolution has begun to expand the usefulness of television beyond its traditional role. Technological developments in recent decades have led to the advent of closed caption television, which integrates a secondary signal into the main television signal. The closed caption data may be decoded and displayed separately on the display system, for example to provide subtitles to hearing-impaired viewers.
An even more recent development is the advent of teletext, which provides a method of broadcasting data by integrating it into the television signal. Like closed caption data, the teletext information is integrated into the television signal without disrupting the television image. As information technology like the Internet develops, teletext is likely to assume a greater role in information systems.
Decoder systems for extracting the teletext and closed caption information from the television signal have been developed and made publicly available. These decoder systems are typically hardware systems integrated into the television circuitry. As the television signal is received by the television, the decoder system continuously monitors the incoming signal for codes indicating that teletext or closed caption data follows. The decoder system then decodes the data “on the fly” and provides it to the user.
Although conventional decoder systems effectively decode and present the data, they suffer several drawbacks. On of the most obvious problems is the cost. The circuitry required to perform the processing in real time is typically dedicated solely to detecting and decoding the teletext and closed caption data. Designing and manufacturing such dedicated circuitry is typically costly. In addition, such systems suffer limited flexibility, as alterations to hardware designs are often costly and difficult to implement, especially after the decoder system has been installed. Further, such systems may be subject to interference that, while of limited effect on the television image, may significantly affect the detection and decoding of the data.
SUMMARY OF THE INVENTION
A teletext and closed caption data decoding system according to various aspects of the present invention provides a software-oriented implementation of the decoding process. The software-oriented implementation tends to reduce the cost of the implementation, as conventional circuitry may be used to perform the decoding and related functions. In addition, the software-oriented decoding system provides for improved efficiency with respect to processing resources, which improves its usefulness in a computer environment. Further, the software may be relatively easily redesigned, tested, and implemented.
In particular, a decoder system according to one embodiment includes a processing unit, such as a microprocessor or a microcontroller, which implements both a closed caption module and a teletext module. The decoder system accumulates digitized video data in a memory until several lines have accumulated. The processing unit then activates either the teletext module or the closed caption module according to which line of data is being analyzed. If the line corresponds to closed caption data, the processor calls the closed caption module, which attempts to detect a clock synchronization signal associated with the closed caption data. Upon finding the clock synchronization signal, the closed caption module synchronizes to the signal and extracts the closed caption data. Similarly, the decoder system may call the teletext module for the teletext lines, which also synchronizes using a teletext clock synchronization signal. When the clock synchronization signal is detected, the teletext module interpolates the incoming data to reconstruct the data signal. The data signal is then processed to reduce multipath or microreflection effects prior to the slicing of the data signal. The data is also suitably subjected to Hamming code error detection to ensure the accuracy of the data.
REFERENCES:
patent: 4380027 (1983-04-01), Leventer
patent: 4424533 (1984-01-01), Rzeszewski
patent: 4434438 (1984-02-01), Rzeszewski
patent: 4673979 (1987-06-01), Kobo et al.
patent: 4719510 (1988-01-01), Kinghorn
patent: 4725886 (1988-02-01), Galumbeck et al.
patent: 4794626 (1988-12-01), Tanabe et al.
patent: 5212551 (1993-05-01), Conanan
patent: 5237290 (1993-08-01), Banu et al.
patent: 5278845 (1994-01-01), Reint Jes et al.
patent: 5301023 (1994-04-01), Zato
patent: 5404172 (1995-04-01), Berman et al.
patent: 5483292 (1996-01-01), Ko
patent: 5504751 (1996-04-01), Ledzius et al.
patent: 5506626 (1996-04-01), Yagi et al.
patent: 5517249 (1996-05-01), Rodriguez-Cavazos et al.
patent: 5530655 (1996-06-01), Lokhoff et al.
patent: 5543850 (1996-08-01), Pratt
patent: 5543852 (1996-08-01), Yuen et al.
patent: 5555025 (1996-09-01), McArthur
patent: 5561469 (1996-10-01), Schultz
patent: 5589886 (1996-12-01), Ezaki
patent: 5596372 (1997-01-01), Berman et al.
patent: 5627593 (1997-05-01), Eitz
patent: 5654763 (1997-08-01), Bruckner et al.
patent: 5657088 (1997-08-01), Hankinson
patent: 5666548 (1997-09-01), Grimm et al.
patent: 5708475 (1998-01-01), Hayashi et al.
patent: 5715011 (1998-02-01), Bramwell
patent: 5812619 (1998-09-01), Runaldue
patent: 5835153 (1998-11-01), Pratt et al.
patent: 5838382 (1998-11-01), Cahill, III
patent: 5953065 (1999-09-01), Cahill, III
Desir Jean W.
Eisenzopf Reinhard J.
Snell & Wilmer L.L.P.
WAVO Corporation
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