Patent ID: 8576052

Claim:
A radio frequency (RF) tag reader and writer comprising: a communication unit configured to communicate with an RF tag as a target from which first information is obtained and obtain the first information held in the RF tag wherein the communication unit comprises a response requesting unit configured to send a response request command to the RF tag over a plural number of times; a response obtaining unit configured to obtain a response sent from the RF tag in response to the response request command; a tag information requesting unit configured to send a tag information request command, which requests a sending of the first information held in the RF tag, to the RF tag in response to the response obtaining unit obtaining the response within a predetermined time after the response requesting unit sends the response request command; and a tag information obtaining unit configured to obtain the first information, which is sent by the RF tag in response to the tag information request command; a communication stability determination unit configured to determine that stable communication with the RF tag is being established in response to a determination that a same set of first information is obtained over a predetermined plural number of times from the RF tag communicating with the communication unit; a tag writing unit configured to write data to the RF tag in response to a determination by the communication stability determination unit that stable communication with the RF tag is being established; and an output adjusting unit configured to set a transmission output of radio waves for a data writing to the RF tag by the tag writing unit to be greater than a transmission output of radio waves for the response request command by the response requesting unit with respect to the RF tag.