Patent ID: 8302867

Claim:
A symbol reading device comprising: an imaging section to capture a symbol and generate a captured image; a detecting section to detect a size of the symbol from the captured image generated by the imaging section; a judging section to judge between large and small by comparing the size of the symbol detected by the detecting section to a pre-set value; a focus movement controlling section to move a focus position of the imaging section to (i) 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 by the judging section, and (ii) 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 by the judging section; and an analyzing section to analyze symbol data corresponding to the symbol from the captured image generated by the imaging section at the focus position moved to by the focus movement controlling section; wherein the detecting section detects the size of the symbol based on a portion showing a coordinate position, the portion being included in the captured image.