Range measuring method, range measuring apparatus, non-contacted IC medium and range measuring system
First Claim
1. A method of measuring a range from a reader unit to a non-contacted IC medium, the method comprising:
- transmitting an inquiry signal at a first frequency from the reader unit to the non-contacted IC medium;
causing the non-contacted IC medium to perform modulation to modulate the first frequency by using a second frequency to obtain a modulated frequency, and causing the non-contacted IC medium to respond to the inquiry signal with a response signal at the modulated frequency, the response signal comprising an upper side band (USB) signal component and a lower side band (LSB) signal component;
causing the reader unit to receive the response signal to acquire a plurality of frequency components by extracting I and Q components from the response signal;
calculating from the extracted I and Q components a phase difference between the upper side band (USB) signal component and the lower side band (LSB) signal component; and
measuring the range by using the calculated phase difference.
1 Assignment
0 Petitions
Accused Products
Abstract
A method of measuring a range from a reader unit to a non-contacted IC medium, includes: transmitting an inquiry signal at a first frequency from the reader unit to the non-contacted IC medium; causing the non-contacted IC medium to perform modulation to modulate the first frequency by using a second frequency to obtain a modulated frequency, and causing the non-contacted IC medium to respond to a response signal at the modulated frequency; causing the reader unit to receive the response signal to acquire a plurality of frequency components; calculating a phase difference between signals of at least two of the acquired plurality of frequency components; and measuring the range by using the phase difference.
-
Citations
11 Claims
-
1. A method of measuring a range from a reader unit to a non-contacted IC medium, the method comprising:
-
transmitting an inquiry signal at a first frequency from the reader unit to the non-contacted IC medium; causing the non-contacted IC medium to perform modulation to modulate the first frequency by using a second frequency to obtain a modulated frequency, and causing the non-contacted IC medium to respond to the inquiry signal with a response signal at the modulated frequency, the response signal comprising an upper side band (USB) signal component and a lower side band (LSB) signal component; causing the reader unit to receive the response signal to acquire a plurality of frequency components by extracting I and Q components from the response signal; calculating from the extracted I and Q components a phase difference between the upper side band (USB) signal component and the lower side band (LSB) signal component; and measuring the range by using the calculated phase difference. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. An apparatus, operable to measure a range from a reader unit to a non-contacted IC medium, the apparatus comprising:
-
a communication unit for transmitting an inquiry signal at a first frequency from the reader unit to the non-contacted IC medium and for receiving a response signal from the non-contacted IC medium, the response signal being generated by modulating the first frequency of the inquiry signal and comprising an upper side band (USB) signal component and a lower side band (LSB) signal component; a frequency component acquiring unit for acquiring the plurality of frequency components from the received response signal by extracting I and Q components from the response signal; and a range measuring unit for calculating from the extracted I and Q components a phase difference between the upper side band (USB) signal component and the lower side band (LSB) signal component, and measuring the range by using the calculated phase difference.
-
-
10. A non-contact IC medium, comprising:
-
a communication unit for receiving an inquiry signal at a first frequency from a reader unit and for responding to the inquiry signal with a response signal to the reader unit, the response signal comprising an upper side band (USB) signal component and a lower side band (LSB) signal component; a modulation unit far performing modulation to modulate the first frequency by using a second frequency to obtain a modulated frequency; and a plurality of modulation circuits corresponding to a plurality of modulation systems, respectively, wherein the communication unit responds to the inquiry signal with the response signal at the modulated frequency, and the response signal is generated by one of a selected one of said modulation circuits and has a plurality of frequency components that enable the reader unit to measure the range from the reader unit to the non-contact IC medium, and wherein the non-contact IC medium sends the response signal having a plurality of frequency components to the reader unit thereby enabling the reader unit to extract I and Q components from the response signal, calculate from the extracted I and Q components a phase difference between the upper side band (USB) signal component and the lower side band (LSB) signal component and measure the range from the reader unit to the non-contact IC medium using the calculated phase difference.
-
-
11. A range measuring system, comprising:
-
a non-contacted IC medium; and a range measuring apparatus operable to measure a range from a reader unit to the non-contacted IC medium, the apparatus comprising; a first communication unit for transmitting an inquiry signal at a first frequency from the reader unit to the non-contacted IC medium and for receiving a response signal from the non-contacted IC medium, the response signal comprising an upper side band (USB) signal component and a lower side band (LSB) signal component; a frequency component acquiring unit for acquiring a plurality of frequency components from the received response signal by extracting I and Q components from the response signal; and a range measuring unit for calculating from the extracted I and Q components a phase difference between the upper side band (USB) signal component and the lower side band (LSB) signal component and measuring the range by using the calculated phase difference, wherein the non-contacted IC medium comprises;
a second communication unit for receiving the inquiry signal at the first frequency from the reader unit, and responding to the inquiry signal with a response signal to the reader unit;
a modulation unit for performing modulation to modulate the first frequency by using a second frequency to obtain a modulated frequency; and
a plurality of modulation circuits corresponding to a plurality of modulation systems, respectively,and wherein the second communication unit responds to the inquiry signal with the response signal at the modulated frequency, and generated by a selected one of said modulation circuits.
-
Specification