This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2005-91415, filed on Mar. 28, 2005 the entire contents of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to desktop systems for reading radio-frequency identification (RFID) tags and method for controlling the reading of radio-frequency identification tags.
2. Description of the Related Art
Readers for reading radio-frequency identification tags stuck to articles generally need to have mount areas of the size suitable for the largest articles with the radio-frequency identification tags. The size of the mount areas tends to increase with the diversification of the line of articles. The increase in the mount areas, i.e., signal transmission and reception areas, allows articles with radio-frequency identification tags to be placed in a wide range.
However, readers having a wide transmission and reception area have increased radio-wave emission and have complicated transmission and reception antennas to ensure accurate communication with radio-frequency identification tags, causing bad influences such as radio wave interference to other electronic devices.
The invention has been made in consideration of the foregoing problems of the bad influences such as an increase in radio wave emission and complicated transmission and reception antennas for accurate communication with radio-frequency identification tags. Accordingly, an advantage of the invention is to provide a reader for transmission and reception without bad influences of radio wave interference to other electronic devices.
To achieve the above advantage, one aspect of the present invention is to provide a desktop system for reading a radio-frequency-identification (RFID) tag, the system including: an article-range finder for finding a range in which an article with an RFID tag is placed; a reader having an antenna for communicating with the RFID tag; and a carrier for carrying the antenna of the reader within the found range of the article.
Another aspect of the present invention is to provide a reading system capable of transmission and reception without bad influences of radio wave interference to other electronic devices, and a method for controlling the reading.
Embodiment of the invention will be described hereinbelow with reference to the drawings.
The flow of the control of the desktop reader according to the embodiment will be specifically described. The article 11 with the RFID tag 12 is placed on the mount surface of the RFID-tag reader 13, with the surface having the RFID tag 12 in a downward direction. Instruction for reading is given to the RFID-tag reader 13 when a start button is pressed or is given with the function of sensing the weight of the article 11, if available.
When the RFID-tag reader 13 receives a read instruction, the article-range finder 31 first senses and recognizes the position and size of the article 11 using the optical sensor 14a and the photodetector 14b. The antenna-shift controller 32 then determines the moving range of the antenna 15 from the range information on the article 11 sensed and recognized by the article-range finder 31 and in consideration of the radio-wave arrival range.
The antenna-shift controller 32 of the carrier 16 instructs the antenna driving section 33 to move the antenna 15 along the rail 17 to the shift start position in the determined moving range using the drive motor.
After completion of the shift of the antenna 15 to the shift start position by the antenna-shift controller 32 of the carrier 16 has been confirmed, the antenna 15 tries to receive the signal of the RFID tag 12. When the reception from the RFID tag 12 has been made normally, the process of reading the RFID tag 12 is performed. On the other hand, the reception was not performed normally, the antenna-shift controller 32 moves the antenna 15 by a specified distance using the antenna driving section 33, and again tries reception of a signal from the RFID tag 12.
The trial of reception from the RFID tag 12 and the shift of the antenna 15 are repeated in the moving range of the antenna 15 until the reception from the RFID tag 12 is normally made under the control of the antenna-shift controller 32.
When the reception could not be executed normally in the moving range of the antenna 15, a notification that communication with the RFID tag 12 is unavailable is given and then the process is terminated.
In this way, the position and size of the article 11 can be recognized using the sensor 14 and the position of the RFID tag 12 can be limited within a specified range. The antenna 15 thus radiates radio waves while moving within the range. This configuration has the advantage of minimizing radio wave output and its emission range. This offers the effects of preventing a bad influence of radio wave interference to other electronic devices.
The foregoing embodiment uses an infrared optical sensor or the like as means for finding the position and size of articles. Optical sensing has the advantage of instantaneous sensing. However, in this invention, mechanical means may be used to determine the size etc.
The two rod sensors 41 can be moved by hand on the rod-sensor support member 42 in the same direction as that of the antenna 15 and the carrier 16. Also, the rod sensors 41 can be turned around the rod-sensor support member 42 toward the mount surface.
The rod sensors 41 also have means for notifying the RFID-tag reader 13 of positional information in the state in which they tilt to the mount surface.
According to the embodiment, relatively low cost mechanical sensors can be used to determine the position and size of articles, thus offering the advantage of providing lower-cost RFID-tag readers.
When the position of the RFID tag on an article is unknown, it is also possible to find the range of the article not only in one direction but also in the direction perpendicular thereto, and to move the antennas in two dimensions within the range, thereby communicating with the RFID tag.
Number | Date | Country | Kind |
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JP2005-091415 | Mar 2005 | JP | national |