PURPOSE: To measure the distance to a transponder, using only existing element by emitting an analog field intensity signal from an RSTP(received signal intensity test pin) of a reader device, and subjecting the obtained signal to a specified processing.
CONSTITUTION: For a transponder 12 on a moving object 10, an antenna 14 of a reader device is arranged in the 90-deg. direction, and is passed by the transponder 12. This form of operation well suits the object 10 located on a conveyor belt or a rairoad track. Approximate position of the transponder 12 is decided by the read/non-read function of the transponder, using only the read output characteristic of the antenna 14. To determine accurate distance in this process, it is necessary to fix the headings of the antenna 14 and transponder 12. If an analog field intensity signal from the RSTP of the reader IC is used, it is possible to decide accurate position of the transponder 12, when signal processing should be made by the use of an A/D converter and a microprocessor.
HORUSUTO MOORITSUKU
KONSUTANTEIN ASURANIDEISU
| JPH0516542Y2 | 1993-04-30 | |||
| JPH0248887U | 1990-04-04 | |||
| JPS5373094A | 1978-06-29 |