초록 ▼

Automatic dispensers for dispensing products such as towel, tissue, wipes, sheet-form materials, soap, shaving cream, fragrances and personal care products. A dispenser includes a housing, an electrical power source, a user input device, a dispensing mechanism, and motor control apparatus. The user

Automatic dispensers for dispensing products such as towel, tissue, wipes, sheet-form materials, soap, shaving cream, fragrances and personal care products. A dispenser includes a housing, an electrical power source, a user input device, a dispensing mechanism, and motor control apparatus. The user input device generates a signal responsive to a user request for product. Motor control apparatus de-powers the dispensing mechanism based on a determination of dispenser conditions representing discharge of the product.

대표청구항 ▼

The invention claimed is: 1. An automatic sheet material dispenser comprising: a housing adapted to receive at least one sheet material roll; an electrical power source; a user input device which generates a user-responsive signal; a dispensing mechanism powered by a motor; and motor control appara

The invention claimed is: 1. An automatic sheet material dispenser comprising: a housing adapted to receive at least one sheet material roll; an electrical power source; a user input device which generates a user-responsive signal; a dispensing mechanism powered by a motor; and motor control apparatus adapted to: power the motor responsive to the signal; repetitively obtain electrical power source output values during powering of the motor; perform mathematical operations using the values to produce a computed value; and de-power the motor when the computed value reaches a target value corresponding to a length of dispensed sheet material. 2. The dispenser of claim 1 wherein the motor control apparatus includes a micro-controller having a memory and a set of instructions adapted to repetitively obtain the values and perform the mathematical operations. 3. The dispenser of claim 2 wherein the values include a power source voltage Vs and a motor current-sensing voltage Vcurr. 4. The dispenser of claim 3 wherein the mathematical operations include repetitively determining dispense sum increments according to the formula, the power source voltage Vs minus three times motor current-sensing voltage Vcurr, and the instructions are adapted to repetitively determine the dispense sum increments. 5. The dispenser of claim 4 wherein the instructions are adapted to sequentially sum the dispense sum increments and to de-power the motor when the sum reaches the target value. 6. The dispenser of claim 5 wherein the motor control apparatus further includes a sheet material length selecting circuit and the selecting circuit is used to select from among a plurality of predetermined target values, each target value corresponding to a predetermined sheet material length. 7. The dispenser of claim 6 wherein the dispensing mechanism comprises: a drive roller powered by the motor; a tension roller positioned against the drive roller to form a nip therebetween, said sheet material being drawn through the nip and out of the dispenser by powering of the drive roller; and wherein the instructions are adapted to compensate for coasting of the dispensing mechanism occurring after motor de-powering, said instructions multiplying a portion of the dispense sum increments by a factor determined by comparing dispense sum increments to an inertia threshold. 8. The dispenser of claim 7 wherein: the factor is applied when the sum of the dispense sum increments reaches a dispense sum threshold; and the factor is varied such that if the dispense sum increment is above the inertia threshold, the motor is de-powered earlier in the dispense cycle and if the dispense sum increment is below the inertia threshold, the motor is de-powered later in the dispense cycle, whereby dispensing mechanism coasting is estimated in a determination of when to de-power the motor. 9. The dispenser of claim 2 wherein the electrical power source is selected from the group consisting of at least one battery and an AC to DC power supply. 10. An automatic product dispenser comprising: a housing adapted to receive a dispensable product; an electrical power source; an electrically-powered dispensing mechanism; and a proximity detector for detecting a user without physical contact by the user, said detector having: a signal responsive to the presence of a user; and a micro-controller having a memory with a set of instructions, said instructions including: a first digital low-pass filter having a time constant, said first filter receiving the signal and providing a first output; and a second digital low-pass filter having a time constant different than the first filter time constant, said second filter receiving the signal and providing a second output, the micro-controller instructions being adapted to determine a difference between the first and second outputs and to operate the dispensing mechanism to dispense the dispensable product responsive to the difference. 11. The dispenser of claim 10 wherein the dispensable product is selected from one or more of the group consisting of towel, tissue, wipes, sheet-form materials, soap, shaving cream, fragrances and personal care products. 12. The dispenser of claim 10 wherein the dispenser is a sheet material dispenser and the dispensing mechanism comprises: a drive roller; a motor in power-transmission relationship with the drive roller; and a tension roller positioned against the drive roller to form a nip therebetween, said sheet material being drawn through the nip and out of the dispenser by powering of the drive roller; and the micro-controller controls the dispensing mechanism to dispense the sheet material responsive to detection of the user. 13. The dispenser of claim 12 wherein the proximity detector further comprises: a sensor element having a capacitance; an oscillator operatively connected to the sensor and having an oscillating voltage output the frequency of which changes based on changes in the capacitance; and a frequency divider operatively connected to the oscillator and constructed to convert the oscillating voltage output into a logical-level square wave. 14. The dispenser of claim 13 wherein the oscillator further includes: an idle-state oscillating voltage output having a frequency range; and a detection-state oscillating voltage output having a frequency range less than the idle-state oscillating voltage output frequency range. 15. The dispenser of claim 13 wherein the frequency divider is adapted to divide the frequency of the oscillating voltage output by a predetermined value as the frequency divider generates the logical-level square wave. 16. The dispenser of claim 15 wherein the logical-level square wave has a nominal frequency of about 1.5 kHz. 17. The dispenser of claim 15 wherein the micro-controller has a clock signal having a clock frequency and wherein the signal responsive to the presence of a user is a stream of numerical values, each numerical value being equal to the number of clock frequency cycles in a fixed number of logical-level square wave cycles. 18. The dispenser of claim 17 wherein: the filters receive the stream of numerical values; the first and second outputs are numerical value streams; the instructions are adapted to determine the difference between the numerical value streams; and the micro-controller powers the motor when the difference between the numerical value streams reaches or exceeds a threshold. 19. The dispenser of claim 18 wherein the instructions are further adapted to de-power the motor when a desired length of sheet material has been dispensed. 20. An automatic sheet material dispenser comprising: a housing defining a space enclosing a sheet material roll; an electrical power source adapted to power the dispenser; a dispensing mechanism for dispensing a length of sheet material from the dispenser, said dispensing mechanism including a drive roller and a motor in power-transmission relationship with the drive roller; a proximity detector for detecting a user without physical contact by the user, said detector having a output signal representing detection of the user; and a controller having a memory and a program of instructions, said instructions including: a first low-pass filter having a time constant, said first filter receiving the output signal and providing a first output; a second low-pass filter having a time constant different from the first filter time constant, said second filter receiving the output signal and providing a second output; and the instructions determine a difference between the first and second outputs, such that the controller powers the motor when the difference reaches or exceeds a predetermined threshold; and wherein the controller is further adapted to: repetitively obtaining electrical power source output values during powering of the motor; repetitively determine dispense sum increments based on the values; sum the determined dispense sum increments; and de-power the motor when the sum reaches or exceeds a target value, whereby sheet material length is controlled to a desired length. 21. The dispenser of claim 20 wherein the proximity detector comprises: a sensor element having a capacitance; an oscillator operatively connected to the sensor and having an oscillating voltage output the frequency of which changes based on changes in the capacitance; and a frequency divider operatively connected to the oscillator and constructed to convert the oscillating voltage output into a logical-level square wave. 22. The dispenser of claim 21 wherein the oscillator further includes: an idle-state oscillating voltage output having a frequency range; and a detection-state oscillating voltage output having a frequency range less than the idle-state oscillating voltage output frequency range. 23. The dispenser of claim 21 wherein the frequency divider is adapted to divide the frequency of the oscillating voltage output by a predetermined value as the frequency divider generates the logical-level square wave. 24. The dispenser of claim 23 wherein the logical-level square wave has a nominal frequency of about 1.5 kHz. 25. The dispenser of claim 23 wherein the controller has a clock signal having a clock frequency and wherein the output signal is a stream of numerical values, each numerical value being equal to the number of clock frequency cycles in a fixed number of logical-level square wave cycles. 26. The dispenser of claim 23 wherein the power source output values comprise a power source voltage Vs and a motor current-sensing voltage Vcurr and the instructions are adapted to repetitively obtain the voltages. 27. The dispenser of claim 26 wherein each dispense sum increment is determined according to the formula, the power source voltage Vs minus three times motor current-sensing voltage Vcurr, and the instructions are adapted to repetitively determine the dispense sum increments. 28. The dispenser of claim 27 wherein the instructions are adapted to sequentially sum the determined dispense sum increments and to de-power the motor when the sum reaches the target value. 29. The dispenser of claim 28 wherein: the power source comprises at least one battery having a life cycle and a voltage which decreases during the life cycle; the dispense sum increment decreases as the voltage decreases during the battery life cycle; and as the dispense sum increment decreases, the number of summing operations required to reach the target value are increased, said increased number of summing operations resulting in an increased time duration to reach the target value, thereby compensating for the voltage decrease by powering the motor for the increased time duration. 30. The dispenser of claim 29 wherein the controller further includes a sheet material length selecting circuit and the selecting circuit is used to select from among a plurality of predetermined target values, each target value corresponding to one predetermined sheet material length. 31. The dispenser of claim 30 wherein the instructions are further adapted to compensate for coasting of the dispensing mechanism occurring after motor de-powering, said instructions multiplying a portion of the dispense sum increments by a factor determined by comparing dispense sum increments to an inertia threshold. 32. The dispenser of claim 31 wherein: the factor is applied when the sum of the dispense sum increments reaches a dispense sum threshold; and the factor is varied such that if the dispense sum increment is above the inertia threshold, the motor is de-powered earlier in the dispense cycle and if the dispense sum increment is below the inertia threshold, the motor is de-powered later in the dispense cycle, whereby dispensing mechanism coasting is estimated in a determination of when to de-power the motor. 33. A method of controlling operation of an automatic product dispenser to detect a user without direct physical contact between the user and the dispenser, the method comprising: sensing a user proximate the dispenser and without direct physical contact between the user and the dispenser; generating an output signal responsive to sensing of the user; receiving the output signal with a first digital low-pass filter residing in instructions in a micro-controller memory, said first filter having a time constant and providing a first output; receiving the output signal with a second digital low-pass filter residing in instructions in the micro-controller memory, said second filter having a time constant different than the first filter time constant and providing a second output; differencing the first and second outputs with the micro-controller instructions; and dispensing product from the dispenser responsive to the difference. 34. The method of claim 33 wherein sensing a user comprises changing a sensor element capacitance responsive to the user proximate the dispenser. 35. The method of claim 34 wherein generating an output signal comprises: changing an oscillating voltage output frequency responsive to the change in sensor element capacitance; and converting the oscillating voltage output to a logical-level square wave. 36. The method of claim 35 wherein changing an oscillating voltage output frequency comprises: providing an idle-state oscillating voltage output when a user is not proximate the dispenser, said idle-state voltage output having a frequency range; and providing a detection-state oscillating voltage output when the user is proximate the dispenser, said detection-state oscillating voltage output having a frequency range less than the idle-state oscillating voltage output frequency range. 37. The method of claim 35 wherein generating an output signal further comprises: repetitively counting a clock oscillator signal for a fixed number of logical square-wave cycles to provide a counted value; and forming a sequential stream of numerical values, each numerical value being equal to the counted value. 38. The method of claim 33 wherein dispensing product from the dispenser further comprises dispensing a product selected from one or more of the group consisting of towel, tissue, wipes, sheet-form materials, soap, shaving cream, fragrances and personal care products. 39. The method of claim 33 wherein dispensing product from the dispenser responsive to the difference comprises dispensing product when the difference reaches a predetermined threshold. 40. The method of claim 39 wherein dispensing product from the dispenser responsive to the difference further comprises powering a dispensing mechanism with the micro-controller when the difference reaches the predetermined threshold. 41. A method of controlling operation of an electronic sheet material dispenser such that the dispenser dispenses a preselected length of sheet material, the method comprising: powering a drive motor in response to a request for sheet material; dispensing a length of sheet material with a dispensing mechanism powered by the drive motor; repetitively obtaining electrical power source output values during powering of the motor; performing mathematical operations using the values to produce a computed value; and de-powering the drive motor when the computed value reaches a target value corresponding a desired length of sheet material, whereby sheet material length is controlled to the desired length. 42. The method of claim 41 wherein repetitively obtaining the electrical power source output values comprises sequentially obtaining a plurality of values of power source voltage Vs and motor current-sensing voltage Vcurr. 43. The method of claim 42 wherein performing mathematical operations using the values comprises: repetitively determining dispense sum increments based on the values; and sequentially summing the dispense sum increments to produce a dispense sum. 44. The method of claim 43 wherein determining the dispense sum increments comprises determining dispense sum increments Q according to the formula, the power source voltage Vs minus three times motor current-sensing voltage Vcurr, and the step of de-powering the drive motor includes de-powering the drive motor when the dispense sum reaches the target value. 45. The method of claim 44 further comprising, before powering the drive motor: selecting a predetermined sheet material length from among a plurality of predetermined sheet material lengths; and setting the target value based on the selected predetermined sheet material length. 46. The method of claim 45 further comprising compensating for coasting of the dispensing mechanism occurring after motor de-powering. 47. The method of claim 46 wherein compensating for coasting of the dispensing mechanism comprises multiplying a portion of the dispense sum increments by a factor determined by comparing dispense sum increments to an inertia threshold. 48. The method of claim 47 further comprising: applying the factor when the sum of the dispense sum increments reaches a dispense sum threshold; and setting the factor such that, if the dispense sum increment is above the inertia threshold, the motor is de-powered earlier in the dispense cycle and if the dispense sum increment is below the inertia threshold, the motor is de-powered later in the dispense cycle, whereby the coasting is estimated in a determination of when to de-power the motor.