Bar code reading method

• US 4,973,829 A
• Filed: 03/30/1989
• Issued: 11/27/1990
• Est. Priority Date: 11/22/1988
• Status: Expired due to Term

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Ishida, Yoshitaka, Izumi, Masaki
• Primary Examiner(s): Pitts, Harold I.
• Application Number:
  US07/330,520
• Time in Patent Office: 607 Days
• Field of Search: 235/462, 235/463, 235/467, 235/472
• US Class Current: 235/462.12
• CPC Class Codes: G06K 7/0166 by means of clock-signals derived from the code marks, e.g. self-clocking code
• CPC Class Codes: G06K 7/14 using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1443 locating of the code in an image
• CPC Class Codes: G06K 7/1456 determining the orientation of the optical code with respect to the reader and correcting therefore
• CPC Class Codes: G06K 7/1491 the method including a reconstruction step, e.g. stitching two pieces of bar code together to derive the full bar code

Abstract

A method of reading bar codes which enables incomplete readings of bar code data produced by excessive misalignment between the bar code and the bar code scanning line to be assembled automatically into a complete reading of the bar code data. This is done by combining incomplete data obtained by multiple passes of the read scanner, using a superimposition technique.

Claims

1. A method of bar code reading in which a scanner sequentially scans and reads data from a bar code, comprising the steps of:

(a) storing incomplete data from a scan that includes either a start mark or a stop mark in a master memory;

(b) storing data read in succeeding scans in a transaction memory;

(c) comparing incomplete data stored in the master memory and read data stored in the transaction memory, superimposing coincident parts thereof and storing such coincident parts in the master memory as composite data; and

(d) repeating steps a-c until the composite data includes a start mark and a stop mark.

2. The bar code reading method of claim 1 wherein when a stop mark is read in step (a) including the further step of reversing ascending data supplied to the master memory and transaction memory.