Wireless tag reading apparatus and control method for a wireless tag reading apparatus

A control method for a wireless tag reading apparatus configured to communicate with a wireless tag that stores information, the wireless tag reading apparatus including:

• an antenna capable of emitting a first linearly polarized wave having a first plane of polarization and a second linearly polarized wave having a second plane of polarization, the second plane of polarization having an orientation that is different from that of the first plane of polarization, and
• first and second power feeding ports to which electric power is supplied, the antenna emitting the first linearly polarized wave when the electric power is supplied to the first power feeding port and the second linearly polarized wave when the electric power is supplied to the second power feeding port, the control method comprising:
• determining a ratio of a first number of wireless tags that are responsive to the first linearly polarized wave to a second number of wireless tags that are responsive to the second linearly polarized wave;
• setting a ratio of a time of power feeding to the first power feeding port to a time of power feeding to the second power feeding port based on the determined ratio;
• switching between the power feeding to the first power feeding port and the power feeding to the second power feeding port in accordance with the set ratio;
• and
• upon receipt of a response wave that is corresponding to the first linearly polarized wave or the second linearly polarized wave via the antenna, reading the information of the wireless tag included in the response wave.