Optical information reading device and optical information reading method

An optical information reading device comprising:

• an imaging module configured to convert reflected light from a reading target symbol into an electric signal and generate image data;
• an aiming module configured to irradiate aiming light for instructing an imaging area of the image data generated by the imaging module;
• a trigger switch for starting imaging processing by the imaging module;
• an aiming switch for causing the aiming module to irradiate the aiming light;
• and
• a reading unit configured to read information of the symbol based on the image data generated by the imaging processing of the imaging module, wherein
• the reading unit is configured to
• determine whether the optical information reading device is in an aiming state in which irradiation processing for the aiming light by the aiming module is executed by operation of the aiming switch at a point in time when the trigger switch is operated, and read, based on the image data generated by the imaging processing of the imaging module, information of the symbol included in a predetermined partial area corresponding to an irradiation position of the aiming light upon determining that the optical information reading device is in the aiming state, the predetermined partial area being narrower than an imaging field of the imaging module.