Distributed type labeling for embedded data blocks

• US 5,572,010 A
• Filed: 01/03/1995
• Issued: 11/05/1996
• Est. Priority Date: 01/03/1995
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Petrie, Glen W.
• Primary Examiner(s): Hajec, Donald T.
• Assistant Examiner(s): TREMBLAY, MARK STEPHEN
• Application Number:
  US08/368,115
• Time in Patent Office: 672 Days
• Field of Search: 235/487, 235/494
• US Class Current: 235/494
• CPC Class Codes: G06K 19/06037 multi-dimensional coding
• CPC Class Codes: G06K 7/143 Glyph-codes

Abstract

Recognizable codes, such as pseudo-noise ("PN") sequence address codes, are employed for type labeling embedded data patterns, such as self-clocking glyph code patterns. For example, this type labeling may be employed to identify structurally distinguished data block types.

Claims

1. A two dimensional embedded data block for storing machine readable information on a recording medium;

said embedded data block comprising a lattice-like synchronization frame composed of embedded data characters for encoding a recognizable address code, said code being selected to provide a type label for said data block and for distinguishing said data block from different data block types.

2. The embedded data block of claim 1 wherein different data block types are identified by different pseudo-noise sequences of the type that are generated by a shift register having a fixed number of stages while using different tap connections.

3. The embedded data block of claim 1 wherein said embedded data block is composed of a self-clocking glyph code pattern.

4. The embedded data block of claim 3 wherein said glyph code pattern is composed of slash-like symbols, said symbols being written on said recording medium on substantially uniformly spaced centers.

5. The embedded data block of claim 4 wherein said glyph code pattern has a substantially uniform grayscale appearance when viewed under ordinary, unaided viewing conditions.

6. A process for type labeling different two dimensional embedded data patterns, each of said embedded data patterns having a lattice-like sync frame composed of spatially distributed embedded data characters;

said process comprising the steps of

correlating each embedded data pattern type with a unique identification code that distinguishes it from all other embedded data pattern types, and;

encoding the identification code that is type correlated with a given embedded data pattern in the sync frame of said given data pattern, thereby applying a distributed type label to the given data pattern.

7. The embedded data pattern of claim 6 wherein said embedded data pattern is a self-clocking glyph code pattern.

8. The embedded data pattern of claim 7 wherein the embedded data characters are slash-like symbols, said symbols being written on said recording medium on substantially uniformly spaced centers.

9. The embedded data block of claim 8 wherein said glyph code pattern has a substantially uniform grayscale appearance when viewed under ordinary, unaided viewing conditions.