Code symbol reading apparatus, code symbol reading method and medium

摘要

A code symbol reading apparatus, that reads a code symbol on an object to be read by scanning the object, repeats trial to read the code symbol until the apparatus succeeds in reading, while changing a transmission frequency of a filter that processes a signal representing a light intensity variation obtained through the scan and in which transmittance depends on a frequency of the signal.

主权项

1. A code symbol reading apparatus that reads a code symbol on an object to be read by scanning the object, comprising:
a filter that processes a signal representing a light intensity variation obtained through the scan, transmittance of the filter depending on frequency of the signal, and a measuring device that measures a period of light intensity variation of an external light, wherein the code symbol reading apparatus sets an initial value of the transmission frequency of the filter based on the period of light intensity variation of the external light measured by the measuring device, and wherein the code symbol reading apparatus repeats trial to read the code symbol, while changing a transmission frequency of the filter, until the code symbol reading apparatus succeeds in the reading.