Paper sheet thickness detecting sensor and banknote classifying unit

Patent metadata

Field	Value
Publication number	US-10269200-B2
Application number	US-201715729949-A
Country	US
Kind code	B2
Filing date	Oct 11, 2017
Priority date	Apr 23, 2015
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

A paper-sheet-thickness detecting sensor of the present invention includes: an oscillator that outputs high-frequency signals with frequencies corresponding to positions in a horizontal direction that is orthogonal to a direction in which a paper sheet is transported; a signal electrode to which the high-frequency signals output by the oscillator are applied; a plurality of detection electrodes that face the signal electrode across a transportation path for the paper sheet and that individually detect detection signals that correspond to the positions; a plurality of resonance circuits that each have one end connected to one end of each of the plurality of detection electrodes and that have resonance frequencies equal to the frequencies allocated to the positions; and a broadband amplifier to which another end of each of the plurality of resonance circuits is connected and that outputs outputs of the plurality of resonance circuits as one piece of sensor output information.

First claim

What is claimed is:

1. A paper-sheet-thickness detecting sensor comprising:
an oscillator that outputs high-frequency signals with frequencies allocated to positions in a horizontal direction that is orthogonal to a direction in which a paper sheet is transported;
a signal electrode to which the high-frequency signals output by the oscillator are applied;
a plurality of detection electrodes that face the signal electrode across a transportation path for the paper sheet and that individually detect detection signals that correspond to the positions;
a plurality of resonance circuits that each have one end connected to one end of each of the plurality of detection electrodes and that have resonance frequencies equal to the frequencies allocated to the positions; and
a broadband amplifier to which another end of each of the plurality of resonance circuits is connected and that outputs outputs of the plurality of resonance circuits as one piece of sensor output information.

2. The paper-sheet-thickness detecting sensor according to claim 1 , wherein
the sensor output information is an amount of change in an output level of the detection signals.

3. The paper-sheet-thickness detecting sensor according to claim 1 , wherein
the sensor output information is an amount of change in a frequency of the detection signals.

4. The paper-sheet-thickness detecting sensor according to claim 1 , wherein
the frequencies of the high-frequency signals output by the oscillator are swept with times allocated to the positions.

5. The paper-sheet-thickness detecting sensor according to claim 1 , wherein
the resonance circuit is a parallel resonance circuit that includes an inductance, a capacitor, and a resistor.

6. The paper-sheet-thickness detecting sensor according to claim 1 , wherein
the resonance circuit is a series resonance circuit that includes an inductance, a capacitor, and a resistor.

7. The paper-sheet-thickness detecting sensor according to claim 5 , wherein
the oscillator stores a frequency and an output level of the high-frequency signals achieved when the paper sheet has been detected, and applies a high-frequency signal with the stored frequency and output level to the signal electrode, so as to compensate for an error in a mechanism of the plurality of detection electrodes and an error in components of the resonance circuit.

8. The paper-sheet-thickness detecting sensor according to claim 6 , wherein
the oscillator stores a frequency and an output level of the high-frequency signals achieved when the paper sheet has been detected, and applies a high-frequency signal with the stored frequency and output level to the signal electrode, so as to compensate for an error in a mechanism of the plurality of detection electrodes and an error in components of the resonance circuit.

9. The paper-sheet-thickness detecting sensor according to claim 1 , wherein
adjacent signal electrodes have applied thereto high-frequency signals whose phases are different from each other by π/2 rad.

10. The paper-sheet-thickness detecting sensor according to claim 9 , wherein
the broadband amplifier and a set of the plurality of resonance circuits have as many isolation buffers as a number of the resonance circuits inserted therebetween.

11. A banknote classifying unit that uses the paper-sheet-thickness detecting sensor according to claim 1 .

Assignees

• Fujitsu Frontech Ltd

Inventors

• Ueoka Tadashi

Classifications

• G07D7/183

  Detecting folds or doubles · CPC title

• G07D7/16

  Testing the dimensions · CPC title

• B65H29/20

  by contact with rotating friction members, e.g. rollers, brushes, or cylinders {(with suction rollers B65H29/243)} · CPC title

• B65H7/06

  responsive to presence of faulty articles or incorrect separation or feed (B65H7/14 takes precedence) · CPC title

• G07D7/162

  Length or width · CPC title