Paper dispenser with proximity detector
First Claim
1. A paper dispenser comprising:
- a housing having an inner chamber adapted to support a roll of paper and having a dispensing aperture;
a motor adapted to dispense paper from the roll of paper through the dispensing aperture; and
a proximity detection circuit comprising;
an antenna;
an oscillator circuit adapted to provide charge to the antenna;
an operational amplifier adapted to operate as a unity gain follower and receiving an antenna signal from the antenna;
a detector circuit adapted to receive the antenna signal via the operational amplifier and to output a detection signal in response to changes in the antenna signal; and
a comparator adapted to receive the detection signal and to actuate the motor in response thereto.
6 Assignments
0 Petitions
Accused Products
Abstract
Apparatus for dispensing paper from rolls which feeds continuously, roll to roll, and does not require extra procedure to bring stub roll into position. The apparatus has means for holding and positioning at least first and second rolls of paper with respect to each other; means for dispensing paper from the first roll; means for dispensing paper from the first and second rolls simultaneously when the first roll reduces to a predetermined diameter of paper, means for positioning the depleted first roll for replacement without the necessity of removing the second roll; and means for dispensing from the second and replacement rolls simultaneously when the second roll reduces to a predetermined diameter of paper. The apparatus also has a proximity sensor, which senses when a hand is placed near the dispenser, and thereupon dispenses a set amount of towel. The proximity sensor incorporates “static” and noise immunity circuitry.
143 Citations
36 Claims
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1. A paper dispenser comprising:
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a housing having an inner chamber adapted to support a roll of paper and having a dispensing aperture;
a motor adapted to dispense paper from the roll of paper through the dispensing aperture; and
a proximity detection circuit comprising;
an antenna;
an oscillator circuit adapted to provide charge to the antenna;
an operational amplifier adapted to operate as a unity gain follower and receiving an antenna signal from the antenna;
a detector circuit adapted to receive the antenna signal via the operational amplifier and to output a detection signal in response to changes in the antenna signal; and
a comparator adapted to receive the detection signal and to actuate the motor in response thereto. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A paper dispenser comprising:
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a housing having an inner chamber adapted to support a roll of paper and having a dispensing aperture;
a motor adapted to dispense paper from the roll of paper through the dispensing aperture; and
a proximity detection circuit comprising;
an antenna;
means for charging the antenna with an oscillating signal;
an operational amplifier adapted to operate as a unity gain follower and to receive an antenna signal from the antenna;
detection means electrically coupled to the operational amplifier and adapted to detect changes in the antenna signal and to generate a detection signal in response thereto; and
means for actuating the motor in response to the detection signal. - View Dependent Claims (8, 9, 10)
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11. An paper dispenser comprising:
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means for supporting a roll of paper within a housing;
means for dispensing paper from the roll of paper;
a proximity detector circuit comprising;
an antenna;
an oscillator circuit adapted to provide charge to the antenna;
an operational amplifier adapted to operate as a unity gain follower and to receive an antenna signal from the antenna;
a detector circuit adapted to receive the antenna signal via the operational amplifier and to output a detection signal in response to changes in the antenna signal; and
a comparator adapted to receive the detection signal and to actuate the dispensing means in response thereto. - View Dependent Claims (12)
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13. A paper dispenser comprising:
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a housing having an inner chamber adapted to support a roll of paper and having a dispensing aperture;
a motor disposed within the housing and adapted to dispense paper from the roll of paper through the dispensing aperture; and
a proximity detection circuit disposed within the housing, the proximity detection circuit comprising;
an antenna;
an asymmetric oscillator circuit electrically coupled to the antenna, the asymmetric oscillator circuit having an on-period and an off-period, wherein the asymmetric oscillator circuit is adapted to send an approximately uniform charge to the antenna during the on-period;
an antenna impedance buffer electrically coupled to the antenna, the antenna impedance buffer including an operational amplifier adapted to operate as a unity gain follower; and
an output comparator electrically coupled to the antenna impedance buffer and to the motor, the output comparator adapted to receive as input a signal from the antenna impedance buffer and a reference voltage, the output comparator being further adapted to actuate the motor when the signal has a predetermined voltage level as compared to the reference voltage. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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20. A method of dispensing paper comprising:
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supporting a roll of paper within a housing, the housing including a dispensing aperture and having a motor affixed thereto;
charging an antenna with an oscillating signal, the antenna being affixed to the housing;
detecting changes in an antenna signal with a detector circuit;
buffering an impedance mismatch between the antenna and the detector circuit with an operational amplifier operated as a unity gain follower;
generating a detection signal from the detector circuit in response to changes in the antenna signal; and
actuating the motor in response to the detection signal, wherein the motor is adapted to dispense paper from the roll of paper through the dispensing aperture upon actuation. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28)
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29. A method of dispensing paper comprising:
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supporting a roll of paper within a housing, the housing including a dispensing aperture and having a motor affixed thereto;
producing an oscillating asymmetric signal having an on period and an off period;
charging an antenna with the oscillating asymmetric signal, the antenna being affixed to the housing, wherein the oscillating asymmetric signal is adapted to provide an approximately uniform amount of charge to the antenna during the on period;
discharging the antenna to a fixed voltage for every oscillation period;
buffering any impedance mismatch between the antenna and a peak detector utilizing an operational amplifier adapted to operate as a unity gain follower;
detecting a peak voltage in the antenna discharge with the peak detector;
actuating the motor upon detection of a signal at the peak detector which is within predetermined duration, amplitude, and rate of change criteria, wherein the motor is adapted to dispense paper from the roll of paper through the dispensing aperture upon actuation. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36)
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Specification