US5543850A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System and method for displaying closed caption data on a PC monitor
Assignee: Nvidia Corp
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Filing: 1995-01-17
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Granted: 1996-08-06
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Expires: 2015-01-17
Abstract
Abstract An apparatus for capturing and decoding the closed caption data from a television signal and displaying the closed caption data, along with the video picture, in a windowing environment on the monitor of a personal computer system. The closed caption decoder device stores the line of video data containing the closed caption text in an object in the frame buffer of the PC. The host CPU reads the raw video data from the frame buffer and stores it in system memory. The host CPU parses the line of video data to separate the two ASCII characters representing closed caption data from the color burst information and synchronizing clock information. After the closed caption data has been retrieved and parity-checked, the closed caption data may be displayed in a window of user-determined size and location on the monitor of the PC, independent of the size and location of the video image window corresponding to the closed caption text.
Inventors
- 👤 Kyle A. Pratt
- 👤 Michael A. Yonker
- 👤 Frank L. Xu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:34
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/025; H04N7/035; H04N7/0255; H04N7/08; H04N7/087; H04N7/088; H04N7/0884; H04N7/0885
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
172 words
A closed caption decoder for capturing closed caption data from a television signal and displaying said closed caption data in a window of user-defined size and location on a screen of a video monitor, said decoder comprising: a video input port for receiving said television signal; a video processor coupled to said video input port, said video processor operable to capture at least one line of video data from a frame of said television signal, wherein said closed caption data is stored in said at least one line of video data; a frame buffer memory coupled to said video processor for storing only a portion of said at least one line of video data; and a second processor coupled to said video processor and to said frame buffer memory for retrieving said portion of at least one line of video data from said frame buffer memory and translating said closed caption data stored in said at least one line of video data into a first ASCII character and a second ASCII character.
Claim 2
Dependent Claim
172 words
A closed caption decoder for capturing closed caption data from a television signal and displaying said closed caption data in a window of user-defined size and location on a screen of a video monitor, said decoder comprising: a video input port for receiving said television signal; a video processor coupled to said video input port, said video processor operable to capture at least one line of video data from a frame of said television signal, wherein said closed caption data is stored in said at least one line of video data; a frame buffer memory coupled to said video processor for storing only a portion of said at least one line of video data; and a second processor coupled to said video processor and to said frame buffer memory for retrieving said portion of at least one line of video data from said frame buffer memory and translating said closed caption data stored in said at least one line of video data into a first ASCII character and a second ASCII character.
Claim 3
Dependent Claim
89 words
The closed caption decoder as set forth in claim 1 wherein said second processor further comprises: means for detecting a plurality of clock pulses contained in said at least one line of video data and determining a logical "1" value associated with a peak amplitude of said plurality of clock pulses, a logical "0" value associated with a blanking level of said at least one line of video data and located between said plurality of clock pulses, and a clock period associated with a frequency of said clock pulses.
Claim 4
Dependent Claim
40 words
The closed caption decoder as set forth in claim 2 wherein said second processor further comprises: means for detecting a start bit associated with said closed caption data, said start bit having an amplitude greater than said logical "1" value.
Claim 5
Dependent Claim
87 words
The closed caption decoder as set forth in claim 3 wherein said second processor further comprises: means for translating said closed caption data into said first and second ASCII characters, wherein said translating means reads a plurality of sampled values of said at least one line of video data at a plurality of intervals after said start bit, each one of said plurality of intervals being a multiple of said clock period, and compares said sampled values to said logical "1" value and said logical "0" value.
Claim 6
Dependent Claim
29 words
The closed caption decoder as set forth in claim 4 wherein said second processor further comprises: means for displaying at least one of said ASCII characters in said window.
Claim 7
Dependent Claim
32 words
The closed caption decoder as set forth in claim 4 wherein said second processor further comprises: means for determining if said first ASCII character is a printable character or a control character.
Claim 8
Dependent Claim
28 words
The closed caption decoder as set forth in claim 4 wherein said second processor further comprises: means for checking the parity of said first and second ASCII characters.
Claim 9
Dependent Claim
32 words
The closed caption decoder as set forth in claim 1 wherein said video processor stores only every other pair of pixel data contained in said at least one line of video data.
Claim 10
Dependent Claim
149 words
A closed caption decoder for capturing closed caption data from a television signal and displaying the closed caption data in a window of user-defined size and location on a screen of a video monitor, said decoder comprising: a video input port for receiving said television signal; a video processor coupled to said video port, said video processor operable to capture a line of video data containing said closed caption data from a frame of said television signal and store only a portion of said line of video data in a frame buffer memory coupled to said video processor as a plurality of pixel data, said pixel data comprising intensity data and color data; and a second processor coupled to said video processor and to said frame buffer for reading from said frame buffer memory a plurality of said intensity data and translating said intensity data into two ASCII characters.
Claim 11
Dependent Claim
149 words
A closed caption decoder for capturing closed caption data from a television signal and displaying the closed caption data in a window of user-defined size and location on a screen of a video monitor, said decoder comprising: a video input port for receiving said television signal; a video processor coupled to said video port, said video processor operable to capture a line of video data containing said closed caption data from a frame of said television signal and store only a portion of said line of video data in a frame buffer memory coupled to said video processor as a plurality of pixel data, said pixel data comprising intensity data and color data; and a second processor coupled to said video processor and to said frame buffer for reading from said frame buffer memory a plurality of said intensity data and translating said intensity data into two ASCII characters.
Claim 12
Dependent Claim
29 words
The closed caption decoder as set forth in claim 9 wherein said video processor stores only every other pair of pixel data contained in said line of video data.
Claim 13
Dependent Claim
86 words
The closed caption decoder as set forth in claim 9 wherein said second processor further comprises: means for detecting a plurality of clock pulses contained in said line of video data and determining a logical "1" value associated with a peak amplitude of said plurality of clock pulses, a logical "0" value associated with a blanking level of said at least one line of video data and located between said plurality of clock pulses, and a clock period associated with a frequency of said clock pulses.
Claim 14
Dependent Claim
40 words
The closed caption decoder as set forth in claim 11 wherein said second processor further comprises: means for detecting a start bit associated with said closed caption data, said start bit having an amplitude greater than said logical "1" value.
Claim 15
Dependent Claim
76 words
The closed caption decoder as set forth in claim 12 wherein said second processor further comprises: means for translating said intensity data into said first and second ASCII characters, wherein said translating means reads selected intensity data at a plurality of intervals after said start bit, each one of said plurality of intervals being a multiple of said clock period, and compares said selected intensity data to said logical "1" value and said logical "0" value.
Claim 16
Dependent Claim
29 words
The closed caption decoder as set forth in claim 13 wherein said second processor further comprises: means for displaying at least one of said ASCII characters in said window.
Claim 17
Dependent Claim
32 words
The closed caption decoder as set forth in claim 13 wherein said second processor further comprises: means for determining if said first ASCII character is a printable character or a control character.
Claim 18
Dependent Claim
28 words
The closed caption decoder as set forth in claim 13 wherein said second processor further comprises: means for checking the parity of said first and second ASCII characters.
Claim 19
Independent Claim
97 words
A method of capturing closed caption data from a television signal and displaying said closed caption data in a window of user-defined size and location on a screen of a video monitor, the method comprising: capturing a line of video data containing the closed caption data from a frame of the television signal; storing only a portion of the captured line of video data in a frame buffer as a plurality of pixel data, the pixel data comprising intensity data and color data; and translating the pixel data stored in the frame buffer into two ASCII characters.
Claim 20
Independent Claim
97 words
A method of capturing closed caption data from a television signal and displaying said closed caption data in a window of user-defined size and location on a screen of a video monitor, the method comprising: capturing a line of video data containing the closed caption data from a frame of the television signal; storing only a portion of the captured line of video data in a frame buffer as a plurality of pixel data, the pixel data comprising intensity data and color data; and translating the pixel data stored in the frame buffer into two ASCII characters.
Claim 21
Dependent Claim
35 words
The method as set forth in claim 17 wherein the step of capturing decimates the line of video data by storing only every other pair of pixel data contained in the line of video data.
Claim 22
Dependent Claim
86 words
The method as set forth in claim 17 wherein the step of translating comprises the substeps of: detecting a plurality of clock pulses contained in the intensity data of the line of video data; and determining a logical "1" value associated with a peak amplitude of the plurality of clock pulses, a logical "0" value associated with a blanking level of the line of video data and located between the plurality of clock pulses, and a clock period associated with a frequency of the clock pulses.
Claim 23
Dependent Claim
46 words
The method as set forth in claim 19 wherein the step of translating comprises the substeps of: detecting a start bit contained in the intensity data, the start bit being associated with the closed caption data and having an amplitude greater than the logical "1" value.
Claim 24
Dependent Claim
81 words
The method as set forth in claim 20 wherein the step of translating comprises the substeps of: sampling the intensity data at a plurality of intervals after the start bit, each of the plurality of intervals being a multiple of the clock period; comparing the sampled intensity data to the logical "1" value and the logical "0" value; and translating the results of the step of comparing the sampled intensity data into a first ASCII character and a second ASCII character.
Claim 25
Dependent Claim
24 words
The method as set forth in claim 21 including the further step of displaying at least one of the ASCII characters in the window.
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) | 1999-08-06 | 2000-02-05 | 2000-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-08-06 | 2004-02-05 | 2004-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-08-06 | 2008-02-05 | 2008-08-06 | $7700.00 | Window Closed / Lapsed |