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US5221833A
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Methods and means for reducing bit error rates in reading self-clocking glyph codes
Assignee: Xerox Corp
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Filing: 1991-12-27
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Granted: 1993-06-22
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Expires: 2011-12-27
Abstract
Abstract The glyphs of a self-clocking glyph code for encoding n-bit long multi-bit digital values are preordered in a cyclical sequence, based on their analytically or empirically determined probabilities of being confused with each other, such that each glyph is adjacent in that sequence to the two glyphs with which it is more likely to be confused during decoding. Binary encoding values then are assigned to these ordered glyphs in accordance with an n-bit long Gray code sequence, so that the value assigned to any given glyph differs in just one bit position from the values assigned to the glyphs with which it is most likely to be confused.
Inventors
- 👤 David L. Hecht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:58
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/14; G06K7/1404; G06K7/1408; G06K7/143; G06K19/00; G06K19/06; G06K19/06009; G06K19/06037
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
110 words
A method for reducing bit errors in reading self-clocking glyph codes that encode n-bit long multi-bit digital values in a set of 2 n graphically discriminable glyphs, said method comprising the steps of identifying a cyclical serial ordering of said glyphs wherein each glyph is an adjacent neighbor of the glyphs with which it is most likely to be confused during said reading, and assigning successive n-bit long Gray code values to said glyphs in accordance with said ordering, whereby the value encoded by each of said glyphs differs from the values encoded by the glyphs with which it is most likely to be confused by just one bit position.
Claim 2
Independent Claim
110 words
A method for reducing bit errors in reading self-clocking glyph codes that encode n-bit long multi-bit digital values in a set of 2 n graphically discriminable glyphs, said method comprising the steps of identifying a cyclical serial ordering of said glyphs wherein each glyph is an adjacent neighbor of the glyphs with which it is most likely to be confused during said reading, and assigning successive n-bit long Gray code values to said glyphs in accordance with said ordering, whereby the value encoded by each of said glyphs differs from the values encoded by the glyphs with which it is most likely to be confused by just one bit position.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said glyphs have different rotational orientations, and said digital values are encoded in the rotational orientations of said glyphs.
Claim 4
Dependent Claim
11 words
The method of claim 2 wherein said glyphs are elongated symbols.
Claim 5
Dependent Claim
23 words
The method of claim 3 wherein the rotational orientations of said glyphs are angularly displaced from each other by substantially equal angular increments.
Claim 6
Independent Claim
18 words
The method of any one of claims 1-4 wherein said cyclical ordering of said glyphs is determined analytically.
Claim 7
Independent Claim
18 words
The method of any one of claims 1-4 wherein said cyclical ordering of said glyphs is determined empirically.
References Cited (Backward Citations)
JPS63193290A
Cited
US5128525A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-06-21 | 1996-12-21 | 1997-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-21 | 2000-12-21 | 2001-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-21 | 2004-12-21 | 2005-06-22 | $7700.00 | Window Closed / Lapsed |