Sensor

• US 20080088201A1
• Filed: 06/08/2007
• Published: 04/17/2008
• Est. Priority Date: 10/13/2006
• Status: Active Grant

• Current Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Inventors: Watanabe, Masao, Konishi, Yasuaki, Mizutani, Ryota, Iida, Kiyoshi, Funo, Hiroyuki
• Granted Patent: US 7,663,290 B2
• Time in Patent Office: Days
• US Class Current: 310/313D
• CPC Class Codes: G06K 19/0672 with resonating marks
• CPC Class Codes: G06K 19/0675 the resonating marks being of the surface acoustic wave [SAW] kind SAW devices per se H03H9/64
• CPC Class Codes: G06K 19/0716 at least one of the integrated circuit chips comprising a sensor or an interface to a sensor
• CPC Class Codes: G06K 7/10009 sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves

Abstract

A sensor includes a substrate, a medium on which a surface acoustic wave propagates, a reference electrode, an antenna, a transducer that includes a first electrode connected to the antenna and a second electrode connected to the reference electrode and arranged opposite to the first electrode, and that has a function of converting a signal received by the antenna into a surface acoustic wave propagating on the medium, and a function of converting a surface acoustic wave propagating on the medium and reaching the transducer into a signal and outputting the signal to the antenna, a reflector that throws back a surface acoustic wave generated by the transducer, propagating on the medium, and reaching the reflector, toward the transducer, and an impedance converter connected to the reference electrode, impedance of which changes in response to a change in circumstances surrounding the sensor.

Claims

1. A sensor comprising:

a substrate;

a medium deposited on the substrate and on which a surface acoustic wave propagates;

a reference electrode deposited on the substrate, that serves as a reference surface of potential;

an antenna that receives and transmits a signal;

a transducer deposited on the medium, that comprises a first electrode connected to the antenna and a second electrode connected to the reference electrode and arranged opposite to the first electrode, and that has a function of converting a signal received by the antenna into a surface acoustic wave propagating on the medium, and a function of converting a surface acoustic wave propagating on the medium and reaching the transducer into a signal and outputting the signal to the antenna;

a reflector that throws back a surface acoustic wave generated by the transducer, propagating on the medium, and reaching the reflector, toward the transducer; and

an impedance converter connected to the reference electrode, impedance of which changes in response to a change in circumstances surrounding the sensor.

2. The sensor according to claim 1, wherein impedance of the impedance converter changes in response to light.

3. The sensor according to claim 1, wherein impedance of the impedance converter changes in response to a change in temperature.

4. A sensor comprising:

a substrate;

a medium deposited on the substrate and on which a surface acoustic wave propagates;

a reference electrode deposited on the surface, that serves as a reference surface of potential;

a first antenna that receives a signal;

a second antenna that sends a signal;

a first transducer deposited on the substrate, that comprises a first electrode connected to the first antenna and a second electrode connected to the reference electrode and arranged opposite to the first electrode, and that converts a signal received by the first antenna into a surface acoustic wave propagating on the medium;

a second transducer deposited on the substrate, that comprises a third electrode connected to the second antenna and a fourth electrode connected to the reference electrode and arranged opposite to the third electrode, and that converts a surface acoustic wave excited by the first transducer, propagating on the medium and reaching the second transducer, into a signal, and outputs the signal to the second antenna; and

an impedance converter connected to the reference electrode, impedance of which changes in response to a change in circumstances surrounding the sensor.

5. The sensor according to claim 4, wherein impedance of the impedance converter changes in response to light.

6. The sensor according to claim 4, wherein impedance of the impedance converter changes in response to a change in temperature.

7. A sensor comprising:

a base means;

a wave transmission means deposited on the base means and on which a surface acoustic wave propagates;

a first electrical connecting means deposited on the bases means, that serves as a reference surface of potential;

a signal transmitting/receiving means for receiving and transmitting a signal;

an energy converting means deposited on the wave transmission means, that comprises a second electrical connecting means connected to the signal transmitting/receiving means and a third electrical connecting means connected to the first electrical connecting means and arranged opposite to the second electrical connecting means, and that has a function of converting a signal received by the signal transmitting/receiving means into a surface acoustic wave propagating on the wave transmission means, and a function of converting a surface acoustic wave propagating on wave transmission means and reaching the energy converting means into a signal and outputting the signal to the signal transmitting/receiving means;

a reflecting means for throwing back a surface acoustic wave generated by the energy converting means, propagating on the wave transmission means, and reaching the reflecting means, toward the energy converting means; and

an impedance converting means connected to the first electrical connecting means, impedance of which changes in response to a change in circumstances surrounding the sensor.