Code reader

• US 4,973,830 A
• Filed: 02/27/1989
• Issued: 11/27/1990
• Est. Priority Date: 05/18/1988
• Status: Expired due to Term

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Sasaki, Hiroaki, Nakase, Koji, Ouchi, Junichi
• Primary Examiner(s): Levy, Stuart S.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/315,975
• Time in Patent Office: 638 Days
• Field of Search: 235/436, 235/437, 235/463, 235/466, 235/474, 235/462, 382/50, 382/53
• US Class Current: 235/462.16
• 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

Abstract

A bit image converter for composing a decoder for converting the value of counting clocks loaded in response to the width of bars or spaces for composing a bar code into character information of a code reader is composed of a module number calculator for calculating the magnification of the basic module from the number of the modules for composing one code unit (one character), a module number total comparator for comparing the total sum of the number of the calculated modules with a specified number n of the modules, a module number corrector for correcting, if the number of the calculated modules is less than the specified number n (n-1), it to the specified number n, and a bit image output unit. Thus, the code reader is adapted for a multilevel bar code system so composed that a result becomes correct information by correcting, if the number of modules for composing one character is less than a specified number n, it.

Claims

1. A code reader for reading a multilevel bar code displayed by n pieces of bars or spaces of the magnification of integer number of the amplitude of a basic module in the magnitude of one code unit as a counted value of clock signals corresponding to the magnitude of the bars or the spaces comprising a module number calculator means for dividing the counted value of the clock signals corresponding to the modules of said bars or spaces by the counted value of the clock signals corresponding to said basic modules to form its quotient and its remainder as one code unit, a module number total comparator means for comparing the total sum of the one code units of said quotient with said n, a module number corrector means for adding "1" to the number of the modules of the bars or spaces corresponding to the maximum remainder of the remainders of said one code unit when the comparison result of said module number total comparator means is (n-1), and a bit image output means for outputting a decode signal when the total sum of the number of the modules of one code unit coincides with said n.