WIRELESS TAG COMMUNICATION DEVICE, INFORMATION PROCESSING APPARATUS, AND RECORDING MEDIUM

• US 20130093569A1
• Filed: 10/11/2012
• Published: 04/18/2013
• Est. Priority Date: 10/17/2011
• Status: Active Grant

• Current Assignee: Toshiba Tec Corporation (Toshiba Corporation)
• Original Assignee: Toshiba Tec Corporation (Toshiba Corporation)
• Inventors: Sano, Kouichi, Yaginuma, Jun, Tsuchida, Sunao
• Granted Patent: US 9,082,026 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• CPC Class Codes: G06K 7/10207 parameter settings related to power consumption of the interrogator
• CPC Class Codes: H04W 52/228 using past power values or information
• CPC Class Codes: H04W 52/287 when the channel is in stand-by
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment

Abstract

According to one embodiment, a wireless tag communication device detects a communication state between an antenna and a specific wireless tag to be searched, stores a transmission power value obtained if the communication state is better than a predetermined value, reduces transmission power to the wireless tag and, if the communication state is worse than the predetermined value, increases, on the basis of the stored transmission power value, the transmission power to be higher than the transmission power value and performs communication with the wireless tag, and performs resetting on the basis of the stored transmission power value if the communication state further worsens.

Claims

1. A wireless tag communication device comprising:

a communication-state detecting section configured to detect a communication state between a specific wireless tag to be searched and an antenna;

a transmission-power storing section configured to store a transmission power value obtained if the communication state detected by the communication-state detecting section is better than a predetermined value;

a transmission-power control section configured to reduce transmission power to the wireless tag and, if the communication-state detecting section detects that the communication state is worse than the predetermined value, increase, on the basis of the transmission power value stored in the transmission-power storing section, the transmission power to be higher than the transmission power value and perform communication with the wireless tag; and

a transmission-power resetting section configured to perform resetting on the basis of the stored transmission power value if the communication-state detecting section detects that the communication state further worsens.

2. The device according to claim 1, wherein

the transmission-power storing section stores, if a detected communication state value detected by the communication-state detecting section is larger than a first threshold, a transmission power value at the communication state value,

the transmission-power control section performs control to decrease transmission power to be transmitted from a radio section if the detected communication state value is larger than the first threshold and performs control to increase the transmission power of the signal to be transmitted from the radio section if the detected communication state value is smaller than the first threshold, and

the transmission-power resetting section performs, if the detected communication state value detected by the transmission-power detecting section decreases to be smaller than a second threshold smaller than the first threshold, resetting of transmission power on the basis of a stored power value stored in the transmission-power storing section and transmits the reset transmission power from the radio section.

3. The device according to claim 1, further comprising a notifying section configured to notify, if the resetting is performed, that the resetting is performed.

4. The device according to claim 1, wherein a transmission power initial value for starting the search for the wireless tag is set in advance on the basis of the transmission power value stored in the transmission-power storing section in an environment in which the device performs communication with the wireless tag.

5. The device according to claim 1, wherein a transmission power minimum value for ending the search for the wireless tag is set in advance on the basis of the transmission power value stored in the transmission-power storing section.

6. An information processing apparatus comprising:

a communication-state determining section configured to detect a communication state in transmission of a signal to a specific wireless tag to be searched and in communication with the wireless tag; and

a transmission-power control section configured to perform control to reduce transmission power of a signal to be transmitted from a radio section if a detected communication state value detected by the communication-state determining section is larger than a first threshold and increase the transmission power of the signal to be transmitted from the radio section if the detected communication state value is smaller than the first threshold.

7. The apparatus according to claim 6, further comprising:

a transmission-power storing section configured to store, if the communication state value is larger than a first threshold, a transmission power value at the communication state value; and

a transmission-power resetting section configured to perform, if the communication state value decreases to be smaller than a second threshold smaller than the first threshold, resetting of the transmission power on the basis, of the stored power value stored in the transmission-power storing section and transmit the reset transmission power from the radio section.

8. The apparatus according to claim 7, wherein a transmission power initial value for starting the search for the wireless tag is set in advance on the basis of the transmission power value stored in the transmission-power storing section in an environment in which the device performs communication with the wireless tag.

9. The apparatus according to claim 8, wherein a transmission power minimum value for ending the search for the wireless tag is set in advance on the basis of the transmission power value stored in the transmission-power storing section.

10. A recording medium having recorded therein a transmission power control program for causing a computer to execute a method of:

detecting a communication state between an antenna and a specific wireless tag to be searched;

storing a transmission power value obtained if the communication state is better than a predetermined value;

reducing transmission power to the wireless tag and, if the communication state is worse than the predetermined value, increasing, on the basis of the stored transmission power value, the transmission power to be higher than the transmission power value and performing communication with the wireless tag; and

performing resetting on the basis of the stored transmission power value if the communication state further worsens.