Patent US6076738A successfully refreshed from Google Patents.
US6076738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-clocking glyph shape codes
Assignee: Xerox Corp
•
Filing: 1994-05-10
•
Granted: 2000-06-20
•
Expires: 2014-05-10
Abstract
Abstract This invention provides self-clocking glyph shape codes for encoding digital data in the shapes of glyphs that are suitable for printing on hardcopy recording media. Advantageously, the glyphs are selected so that they tend not to degrade into each other when they are degraded and/or distorted as a result, for example, of being photocopied, transmitted via facsimile, and/or scanned-in to an electronic document processing system. Moreover, for at least some applications, the glyphs desirably are composed of printed pixel patterns containing nearly the same number of ON pixels and nearly the same number of OFF pixels, such that the code that is rendered by printing such glyphs on substantially uniformly spaced centers appears to have a generally uniform texture. In the case of codes printed at higher spatial densities, this texture is likely to be perceived as a generally uniform gray tone. Binary image processing and convolution filtering techniques for decoding such codes also are diclosed, but this application focuses on the codes.
Inventors
- 👤 Dan S. Bloomberg
- 👤 David L. Hecht
- 👤 Robert F. Tow
- 👤 L. Prasadam Flores
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:06
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; G06K7/01; G06K7/016; G06K7/0166; G06V; G06V30/00; G06V30/10; G06V30/22; G06V30/224
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
104 words
A method for storing digital values of predetermined bit length, n, in a machine readable format on a hardcopy recording medium, said method comprising the steps of encoding each of said digital values in a corresponding one of 2 n physically distinct, distinctive, rotationally variant, substantially equal surface area, individually discriminable glyph shapes to generate a set of mutually independent glyph shapes that vary in accordance with said digital values, and writing said set of glyph shapes on said recording medium in a predetermined logical order and in accordance with a predetermined spatial formatting pattern for storing said digital values in a self-clocking code.
Claim 2
Independent Claim
104 words
A method for storing digital values of predetermined bit length, n, in a machine readable format on a hardcopy recording medium, said method comprising the steps of encoding each of said digital values in a corresponding one of 2 n physically distinct, distinctive, rotationally variant, substantially equal surface area, individually discriminable glyph shapes to generate a set of mutually independent glyph shapes that vary in accordance with said digital values, and writing said set of glyph shapes on said recording medium in a predetermined logical order and in accordance with a predetermined spatial formatting pattern for storing said digital values in a self-clocking code.
Claim 3
Dependent Claim
49 words
The method of claim 1 wherein said digital values are single bit values, and said glyph shapes are elongated along axes that are tilted at angles of approximately plus and minus 45° with respect to a reference axis for distinguishing different ones of said digital values from each other.
Claim 4
Dependent Claim
18 words
The method of claim 2 wherein said reference axis extends substantially horizontally with respect to said recording medium.
Claim 5
Independent Claim
102 words
A method for storing digital values of predetermined bit length, n, in a machine readable format on a hardcopy recording medium, said method comprising the steps of encoding each of said digital values in a corresponding one of 2 n distinctive, rotationally invariant, substantially equal surface area, individually discriminable glyph shapes to generate a set of mutually independent glyph shapes that vary in accordance with said digital values, and writing said set of glyph shapes on said recording medium in a predetermined logical order and in accordance with a predetermined spatial formatting pattern for storing said digital values in a self-clocking code.
Claim 6
Independent Claim
102 words
A method for storing digital values of predetermined bit length, n, in a machine readable format on a hardcopy recording medium, said method comprising the steps of encoding each of said digital values in a corresponding one of 2 n distinctive, rotationally invariant, substantially equal surface area, individually discriminable glyph shapes to generate a set of mutually independent glyph shapes that vary in accordance with said digital values, and writing said set of glyph shapes on said recording medium in a predetermined logical order and in accordance with a predetermined spatial formatting pattern for storing said digital values in a self-clocking code.
Claim 7
Independent Claim
46 words
The method of any of claims 1-4 wherein said glyph shapes are defined by respective two dimensional pixel arrays of predetermined size, each of which contains a predetermined number of ON pixels and a predetermined number of OFF pixels, and said spatial pattern is spatially periodic.
Claim 8
Dependent Claim
29 words
The method of claim 5 wherein said pixel arrays are written on said recording medium in spatially abutting relationship, such that said code has a generally uniform, textured appearance.
Claim 9
Independent Claim
24 words
The method of any of claims 1-4 wherein said glyph shapes are of substantially uniform macroscopic appearance, and said spatial pattern is spatially periodic.
Claim 10
Dependent Claim
31 words
The method of claim 7 wherein said glyph shapes are written on said recording medium at a sufficiently high spatial density to impart a generally uniform, textured appearance to said code.
References Cited (Backward Citations)
US3257545A
Cited
US3654435A
Cited
US3898434A
Cited
US4115806A
Cited
US3978319A
Cited
US4286146A
Cited
US4630308A
Cited
US4817171A
Cited
US4610025A
Cited
WO1986000445A1
Cited
GB2179008A
Cited
US4728783A
Cited
US4754127A
Cited
JPS62140554A
Cited
US4905296A
Cited
US4980923A
Cited
US4924078A
Cited
US5073954A
Cited
US5091966A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-06-20 | 2003-12-20 | 2004-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-06-20 | 2007-12-20 | 2008-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-06-20 | 2011-12-20 | 2012-06-20 | $7700.00 | Window Closed / Lapsed |