Method for enhancing the reliability of output data from a label reader

• US 4,175,693 A
• Filed: 03/29/1978
• Issued: 11/27/1979
• Est. Priority Date: 04/07/1977
• Status: Expired due to Term

• Current Assignee: Shinko Electric Industries Company Limited (Fujitsu Limited)
• Original Assignee: Shinko Electric Industries Company Limited (Fujitsu Limited)
• Inventors: Suzuki, Kazuhiro, Endo, Shinichiro, Nakanishi, Sadao, Tokura, Nobufumi
• Primary Examiner(s): Kilgore, Robert M.
• Application Number:
  US05/891,219
• Time in Patent Office: 608 Days
• Field of Search: 235/463, 235/464, 235/465, 235/466, 250/566, 340/146.3 F, 340/146.3 Z, 340/149 A, 340/149 R
• US Class Current: 235/462.07
• CPC Class Codes: G06K 5/00 Methods or arrangements for verifying the correctness of markings on a record carrier; Column detection devices
• CPC Class Codes: G06K 7/10861 sensing of data fields affixed to objects or articles, e.g. coded labels postal sorting B07C3/14, conveying articles B65G47/48

Abstract

A method for enhancing the reliability of output data from a label reader adapted to read a bar code consisting of a plurality of bars. Each bar in the bar code is scanned at a plurality of points and sets of binary symbols representative of the scanned points along each bar are obtained. Two sums are then formed for each bar, the first being the number of binary "1"s in the set and the second being the number of binary "0"s in the set, and the ratio of two sums is computed. If the ratio is larger than (1+α) for α>0, then the data corresponding to the numerator sum is regarded as reliable. If the ratio is less than (1-β) for 0<β<1, then the data corresponding to the denominator sum is regarded as reliable. If the ratio is equal to or larger than (1-β) but equal to or less than (1+α), then the data is regarded as unreliable.

Claims

1. A method for enhancing the reliability of the output data from a label reader having a scanner and adapted to read a bar code consisting of a plurality of bars comprising the steps of:

obtaining a set of binary signals, each signal in said set being representative of a particular different point along a particular bar as scanned by the scanner;

forming a first sum equal to the number of binary "1" signals in said set;

forming a second sum equal to the number of binary "0" signals in said set;

computing the ratio (R) of said first sum to said second sum;

providing a binary "1" output decision for the particular bar if R>

(1+α

) where α

>

0;

providing a binary "0" output decision for the particular bar if R>

(1-β

) where 0<

β

<

1; and

determining that a reliable output decision cannot be made for the particular bar if (1-β

)≦

R≦

(1+α

).

2. The method according to claim 1 wherein the bars comprising said bar code comprise a mix of wide bars and narrow bars.

3. The method according to claim 2 wherein a plurality of binary "1" signals are obtained for said set if the particular bar is a wide bar;

and wherein a plurality of binary "0" signals are obtained for said set if the particular bar is a narrow bar.

4. The method according to claim 2 wherein a plurality of binary "1" signals are obtained for said set if the particular bar is a narrow bar, and wherein a plurality of binary "0" signals are obtained for said set if the particular bar is a wide bar.