Granted Patent B2

US 7,537,384 · App. 11/597,882 · Granted May 26, 2009

Assignee: NXP B.V.

Abstract

Claims (24)

1. A temperature-recording method for recording a temperature by means of an electrical circuit of a data storage medium, which electrical circuit is suppliable with energy by means of a signal feedable to the data storage medium, the method comprising:

recording of a physical variable dependent on the temperature by means of the circuit supplied with energy, the physical variable being influenced by a temperature-recording material comprising a piezoelectric or ferroelectric material, co-operating with the circuit, which material comprises alignable electric or magnetic elementary dipoles and for which temperature-recording material a Curie temperature is known, wherein the alignment of the elementary dipoles gradually decreases over a limited temperature range which exceeds the Curie temperature.

2. A temperature-recording method as claimed in claim 1 , wherein the recording of the physical variable dependent on the alignment of the elementary dipoles comprises:

determining a reference value of the physical variable with the elementary dipoles of the temperature-recording material aligned; and

comparing an instantaneous value of the physical variable with the reference value.

3. A temperature-recording method as claimed in claim 1 , further comprising re-activating the temperature-recording material through re-alignment of the electric or magnetic dipoles, by applying an electrical or magnetic field.

4. A temperature-recording method as claimed in claim 1 , wherein the recording of the physical variable dependent on the alignment of the electric or magnetic elementary dipoles comprises the recording of an electric voltage, or of a mechanical deformation or of a change in an electrical resistance and/or in an inductance and/or in an electrical capacitance.

5. A temperature-recording method as claimed in claim 4 , wherein the recording of the physical variable dependent on the alignment of the elementary dipoles comprises the-opening or closing of electrical contacts by mechanical deformation of the temperature-recording material in dependence on the alignment of the elementary dipoles.

6. A temperature-recording arrangement for recording a temperature, comprising:

a temperature-recording material comprising a piezoelectric or ferroelectric material with alignable electric or magnetic elementary dipoles, wherein the temperature-recording material has a Curie temperature which corresponds to a pre-determined limit temperature, wherein the alignment of the elementary dipoles gradually decreases in response to the temperature exceeding the Curie temperature; and

means for recording a physical variable dependent on the alignment of the elementary dipoles in the temperature-recording material, comprising:

a data storage medium; and

an electrical circuit coupled to the temperature-recording material, wherein the electrical circuit is suppliable with energy by means of a signal feedable to the data storage medium, and the electrical circuit is configured to record the physical variable on the data storage medium.

7. A temperature-recording arrangement as claimed in claim 6 , wherein the means for recording the physical variable dependent on the alignment of the electric or magnetic elementary dipoles are configured to determine a reference value of the physical variable with the elementary dipoles of the temperature-recording material aligned and to compare an instantaneous value of the physical variable with the reference value.

8. A temperature-recording arrangement as claimed in claim 6 , wherein the temperature-recording material is re-activatable through re-alignment of the electric or magnetic dipoles, by applying an electric or magnetic field.

9. A temperature-recording arrangement as claimed in claim 6 , further comprising a communications interface for contactlessly reading out the physical variable recorded by the temperature-recording arrangement in dependence on the alignment of the elementary dipoles of the temperature-recording material.

10. The temperature-recording arrangement of claim 6 , wherein the electrical circuit comprises:

an inductor comprising the ferroelectric material;

a diode coupled to the inductor, the diode to rectify a partial voltage from the inductor;

a capacitor coupled in series between an output of the diode and a ground reference, the capacitor in combination with the inductor to form an alternating voltage divider, wherein the capacitor is configured to smooth the partial voltage rectified by the diode;

first and second resistors coupled in parallel with the capacitor, the first and second resistors to form a second voltage divider to output a drive voltage dependent on the temperature of the ferroelectric material; and

a transistor coupled to the first and second resistors, the transistor to receive the drive voltage from the second voltage divider and to generate an output voltage dependent on the drive voltage, wherein a magnitude of the output voltage changes relative to a change in the temperature of the ferroelectric material.

11. A temperature-recording arrangement as claimed in claim 6 , wherein the means for recording the physical variable dependent on the alignment of the electric or magnetic elementary dipoles are configured to record an electric voltage, or a mechanical deformation or a change in an electrical resistance and/or in an inductance and/or in an electrical capacitance.

12. A temperature-recording arrangement as claimed in claim 11 , wherein the means for recording the physical variable dependent on the alignment of the electric or magnetic elementary dipoles are configured to determine an opening or a closing of electrical contacts by mechanical deformation of the temperature-recording material in dependence on the alignment of the elementary dipoles.

Assignments (13)

Priority Claims (1)

Continuity (1)