发明名称 Position information detection system and position information detection method
摘要 An object of the present invention is to achieve a position information detection system with high precision when an obstruction and a reflective object exist. A position information detection system includes a reader/writer whose position is known, a first RF chip whose position is known, and a second RF chip attached to an object to be detected; and calculates a distance between the reader/writer and the second RF chip from a first calculated distance between the reader/writer and the first RF chip, which is calculated from a signal intensity of a communication signal transmitted from the reader/writer, detected by the first RF chip, a second calculated distance between the second RF chip and the reader/writer, which is calculated from a signal intensity of a communication signal transmitted from the reader/writer, detected by the second RF chip, and a distance between the reader/writer and the first RF chip.
申请公布号 US2008174492(A1) 申请公布日期 2008.07.24
申请号 US20070819578 申请日期 2007.06.28
申请人 SEMICONDUCTOR ENERGY LABORATORY CO., LTD. 发明人 KUROKAWA YOSHIYUKI
分类号 G01S3/00;G01S5/02 主分类号 G01S3/00
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