SYMBOL READING DEVICE, SYMBOL READING METHOD AND PROGRAM RECORDING MEDIUM TO CONTROL FOCUS BASED ON SIZE OF CAPTURED SYMBOL

Disclosed is a symbol reading device including: an imaging section to capture a symbol and generate an image; a detecting section to detect a size of the symbol; a judging section to judge large or small by comparing the size of the symbol to a pre-set value; a focus movement controlling section to move a focus position of the imaging section to a predetermined position of a farther side when the size of the symbol is smaller than the pre-set value as a result of the judgment, and to move a focus position of the imaging section to a predetermined position of a closer side when the size of the symbol is larger than the pre-set value as a result of the judgment; and an analyzing section to analyze symbol data corresponding to the symbol at a focus position moved by the focus movement controlling section.