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US 7,607,829 B2Granted
Resonance tag with temperature sensor
AssigneeCanon Kabushiki Kaisha
InventorsTakayuki Sumida, Tadahiko Hirai
Life of this patent
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Abstract
A temperature-history sensor includes a resonance circuit composed of at least a capacitor and a coil. The temperature-history sensor has a display for indicating a predetermined set temperature of the temperature-history sensor. The capacitor has at least a thermofusion material between electrodes of the capacitor, and the melting point of the thermofusion material is in the region of the set temperature.
Claims5
A temperature-history sensor comprising:
- a resonance circuit comprising:
- a capacitor;
- and
- a coil;
- a thermofusion material;
- a reservoir portion for stocking the thermofusion material;
- a flow path for supplying the thermofusion material from the reservoir portion to between electrodes of the capacitor;
- and
- a display for indicating a predetermined set temperature of the temperature-history sensor,
- wherein a melting point of the thermofusion material is in a region of the set temperature, and
- wherein at least a part of the thermofusion material fuses due to heat and flows to between the electrodes of the capacitor so as to change an effective dielectric constant of the capacitor.
8 more elements
A temperature-history sensor comprising:
- a resonance circuit comprising:
- a capacitor;
- and
- a coil;
- wherein a change of an effective dielectric constant of the capacitor changes a resonance characteristic of the resonance circuit,
- wherein the capacitor includes a pair of electrodes which face each other and are separate from each other via a gap,
- wherein a first material becomes fluidized at a first temperature and moves into the gap or to outside of the gap, so that an effective dielectric constant is changed, and as a result, the resonance circuit has a first resonance characteristic, and
- wherein a second material becomes fluidized at a second temperature which is higher than the first temperature and moves into the gap or to outside of the gap, so that the effective dielectric constant is changed, and as a result, the resonance circuit has a second resonance characteristic.
5 more elements
Dependencies are inferred from the claim text.