WO2011059423A1 - Distributeur avec système de détection de quantité presque épuisée de matériau - Google Patents

Distributeur avec système de détection de quantité presque épuisée de matériau Download PDF

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Publication number
WO2011059423A1
WO2011059423A1 PCT/US2009/006131 US2009006131W WO2011059423A1 WO 2011059423 A1 WO2011059423 A1 WO 2011059423A1 US 2009006131 W US2009006131 W US 2009006131W WO 2011059423 A1 WO2011059423 A1 WO 2011059423A1
Authority
WO
WIPO (PCT)
Prior art keywords
motor
sheet material
dispenser
roll
pulses
Prior art date
Application number
PCT/US2009/006131
Other languages
English (en)
Inventor
James A. Rodrian
Sigurdur S. Witt
Original Assignee
Alwin Manufacturing Co., Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alwin Manufacturing Co., Inc. filed Critical Alwin Manufacturing Co., Inc.
Priority to PCT/US2009/006131 priority Critical patent/WO2011059423A1/fr
Priority to EP09756869.5A priority patent/EP2501267B1/fr
Priority to ES09756869.5T priority patent/ES2584933T3/es
Publication of WO2011059423A1 publication Critical patent/WO2011059423A1/fr

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Classifications

    • A—HUMAN NECESSITIES
    • A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
    • A47K—SANITARY EQUIPMENT NOT OTHERWISE PROVIDED FOR; TOILET ACCESSORIES
    • A47K10/00—Body-drying implements; Toilet paper; Holders therefor
    • A47K10/24—Towel dispensers, e.g. for piled-up or folded textile towels; Toilet-paper dispensers; Dispensers for piled-up or folded textile towels provided or not with devices for taking-up soiled towels as far as not mechanically driven
    • A47K10/32—Dispensers for paper towels or toilet-paper
    • A47K10/34—Dispensers for paper towels or toilet-paper dispensing from a web, e.g. with mechanical dispensing means
    • A47K10/36—Dispensers for paper towels or toilet-paper dispensing from a web, e.g. with mechanical dispensing means with mechanical dispensing, roll switching or cutting devices
    • A47K10/3606—The cutting devices being motor driven
    • A47K10/3612—The cutting devices being motor driven with drive and pinch rollers

Definitions

  • the field relates generally to dispenser control, and more particularly, to controlling a dispenser to indicate that a low-material state exists.
  • Automatic sheet material dispensers such as paper towel dispensers and the like, are widely used to supply paper towel and other types of sheet material to persons in public restrooms, kitchens, food-preparation facilities and other settings in which hygiene and cleanliness are desired or in which sheet material is desired for some other purpose.
  • the sheet material dispensed by these dispensers is typically in the form of a web wound into a roll on a core. The sheet material is unwound from the roll by the dispenser and is dispensed to the user.
  • a typical automatic paper towel dispenser is a battery-operated device with a direct current (DC) motor that is activated by a proximity sensor or contact switch.
  • a controller controls the DC motor to dispense a predetermined amount of sheet material (e.g., 12 inches) for each activation of the proximity sensor or contact switch.
  • a problem with automatic sheet material dispensers is that it can be difficult for the attendant to determine the amount of sheet material remaining on the roll and to determine whether a
  • replacement roll should be loaded in the dispenser. It can be difficult to determine the amount of material remaining in the dispenser because the roll typically cannot be seen within the opaque dispenser housing. Therefore, the attendant must manually unlock and open the dispenser to view the roll and to determine whether a
  • Low-material sensing apparatus, systems and methods are disclosed for indicating that sheet material dispensed from a sheet material roll is depleted or nearing depletion.
  • the low-material sensing provides an indication that the depleted sheet material roll should be replaced with a full roll. This arrangement makes it possible to quickly and easily determine whether the sheet material roll requires replacement without having to open the apparatus to look at the sheet material roll.
  • a highly-preferred application of the low-material sensing apparatus, systems and methods is in an automatic paper towel dispenser, although the low-material sensing may be implemented in other apparatus.
  • the low-material sensing system includes a sensor, a motor, and a controller which controls the dispenser to provide an indication that a low- material state exists.
  • the indication is an indicator which is activated by the controller and alerts the attendant of the low-material state.
  • the preferred controller provides a circuit which is preferably coupled to the sensor, motor and indicator and preferably includes a software-controlled microcontroller with an embedded analog-to-digital (A/D) converter.
  • A/D analog-to-digital
  • the sensor generates a sensor signal indicative of sheet material roll rotation.
  • the motor has an armature and produces movement of the sheet material when current is supplied to the motor.
  • the motor produces a motor signal indicative of at least one of motor current and motor voltage as the armature rotates.
  • the motor signal is produced when current supply to the motor is activated and when current supply to the motor is deactivated and the motor is coasting.
  • the circuit supplies to the microcontroller processing device a digitized motor signal indicative of at least one of motor current and motor voltage and a digitized sensor signal. Digitizing of the motor signal and sensor signal is preferably performed by the embedded A/D converter of the microcontroller.
  • the preferred controller is further operable to detect pulses in the digitized motor signal during a time interval of motor armature rotation and to detect pulses in the digitized sensor signal during a time interval of sheet material roll rotation.
  • the time intervals of digitized sensor signal and digitized motor signal pulse detection need not be identical.
  • the controller is operable to detect pulses in the digitized motor signal after current supply to the motor is deactivated.
  • the microcontroller can also be configured to detect the digitized motor signal while current is supplied to the motor.
  • the preferred controller determines the rotational speed of the motor from the digitized motor signal and determines the rotational speed of the sheet material roll from the digitized sensor signal.
  • the controller further compares the rotational speeds and controls the dispenser to provide the low-material state indication when the comparison reaches a threshold representative of a low-material state.
  • the comparison is a determination of the ratio of the rotational speeds and the indicator is activated when the ratio of the sheet material roll speed to the motor speed exceeds a preset threshold.
  • the controller is operable to measure a time interval of motor armature rotation between detected pulses. It is highly preferred that the motor pulse detection comprises detecting three contiguous pulses and the time interval measurement comprises measuring the time between the first and last of the contiguous pulses.
  • a highly preferred sensor type is a bar code sensor which senses a bar code on the sheet material roll. It is highly preferred that the sheet material is wound on a core and the bar code is located on a core inner surface. It is preferred that the bar code sensor is on a support for the roll.
  • a preferred bar code sensor may include an optical source operable to direct optical energy toward the bar code and an optical detector operable to receive optical energy from the bar code to generate the sensor signal.
  • the low-material indication controlled by the controller may include activation by the controller of any indicator capable of indicating the low-material state. It is preferred that the low-material indicator is a visual or audible indicator. A lamp visible to a person responsible for replacing the sheet material roll is a suitable type of visual indicator. A light-emitting-diode (LED) is a particularly preferred type of lamp. Other indications, such as dispensing a shortened sheet material length in the next dispense cycle, could be implemented.
  • a preferred method of indicating that a supply of sheet material on a roll is low comprises digitizing a motor signal indicative of at least one of motor current and motor voltage and a sensor signal indicative of sheet material roll rotation, detecting pulses in the digitized motor signal during a time interval of motor armature rotation and determining the rotational speed of the motor therefrom, detecting pulses in the digitized sensor signal during a time interval of sheet material roll rotation and determining rotational speed of the sheet material roll therefrom, comparing the rotational speeds, and providing an indication when the comparison reaches a threshold representative that the supply of sheet material on the roll is low.
  • the preferred indication is activating an indicator which alerts the attendant that the material is low.
  • FIGURE 1 is a simplified diagram of a sheet material dispenser, in the form of a paper towel dispenser, taken along section 1-1 of Figure 2 in accordance with one embodiment of the present invention
  • FIGURE 2 is a simplified diagram of the exemplary dispenser taken along section 2-2 of Figure 1 ;
  • FIGURE 3 is an enlarged partial view of an exemplary roll holder and sensor taken along section 3-3 of Figure 2;
  • FIGURE 4 is an exploded view of the roll holder and sensor of Figure 3;
  • FIGURE 5 is an exemplary sheet material roll, in the form of a paper towel roll, wound on a core which includes a machine-readable code;
  • FIGURE 6 is the sheet material roll taken along section 6-6 of Figure 5;
  • FIGURE 7 is a circuit diagram of an exemplary control system that may be used with the dispenser of Figures 1-4;
  • FIGURE 8 are plural copies of an exemplary bar code provided on a core inside surface as seen in an unrolled state
  • FIGURE 8A illustrates an enlarged portion of the bar code taken along section 8A-8A of Figure 8;
  • FIGURE 9 is the bar code of Figure 8 A together with a graph illustrating a digitized sensor signal corresponding such bar code;
  • FIGURE 9A illustrates an enlarged portion of the bar code and graph taken along section 9A-9A of Figure 9;
  • FIGURE 10 is a graph illustrating a digitized motor signal during powered motor operation and, subsequently, during motor armature coasting after the motor is depowered;
  • FIGURES 1 1 A-l ID are logic flow diagrams of the general logic implemented by the controller to control the dispenser embodiment of Figures 1-4 and 7; and
  • FIGURE 12 is a logic flow diagram of an alternative embodiment of the general logic implemented by the controller that may be used to control the dispenser embodiment of Figures 1 -4 and 7.
  • FIG. 1-6 simplified diagrams of a sheet material dispenser 10 and a sheet material roll 1 1 in accordance with one embodiment of the present invention are provided.
  • the exemplary sheet material dispenser 10 shown in these figures is a paper towel dispenser which dispenses sheet material 12 in the form of paper towel from a paper towel roll 11. While the exemplary dispenser 10 is described herein as a paper towel dispenser, it will be apparent to a person of skill in the art that dispenser 10 may dispense sheet material other than paper towel 12. Other materials which could be dispensed from dispenser 10 could include toilet tissue, kraft paper, cotton-based cloth, plastic sheet, films, and the like. Dispenser 10 could be configured to dispense tickets, receipts and other sheet-form material.
  • the exemplary sheet material dispenser 10 shown in these figures is a paper towel dispenser which dispenses sheet material 12 in the form of paper towel from a paper towel roll 11. While the exemplary dispenser 10 is described herein as a paper towel dispenser, it will be apparent to a person of skill in the art that dispenser 10 may dispense sheet
  • Dispenser 10 includes a low-material sensing system.
  • the dispenser 10 low- material sensing system determines that a low-material state exists and provides an indication to alert an attendant that the sheet-material roll 1 1 supplying material 12
  • the parameters defining a low-material state can be determined and set based the needs of the party providing the dispenser 10 for users. For example, some dispenser providers may wish to define the low-material state as including relatively more material remaining on the roll 1 1 than would other dispenser providers.
  • the low-material sensing system described herein may be designed to activate the low- material indicator to accommodate these potentially different needs; there is no particular amount of material depletion required before activation of the low-material indicator.
  • exemplary paper towel dispenser 10 includes a roll 1 1 of paper material 12 supported in a housing 13. Paper 12 is pulled though a nip 15 formed by a drive roller 17 and a tension or "nip" roller 19 which is biased toward drive roller 17 by springs (not shown) or the like.
  • a direct current (DC) motor 21 has an armature 23 with an output shaft 24 to which gear 25 is attached. Gear 25 on output shaft 24 meshes with intermediate gear 27 and intermediate gear 27 meshes with drive roller gear 29 which is mounted on drive roller shaft 31. Motor 21 powers gears 25, 27, 29 resulting in rotation of drive roller 17 in the direction of arrow 33.
  • motor 21 is in power-transmission relationship with drive roller 17.
  • a linkage other than gears 25, 27 and 29 may be utilized.
  • Gears 25, 27 and 29 collectively provide a reduction-gear arrangement in this example.
  • Paper 12 from roll 1 1 is dispensed through a slot 35 in housing 13.
  • One edge 37 of slot 35 may have a serrated surface to cut paper 12 as a user grasps paper 12 extending beyond slot 35 and pulls the paper 12 into contact with the serrated surface on edge 37.
  • controller 39 receives an input from a proximity sensor 41 and controls current to motor 21. Once current is supplied to motor 21, motor 21 is activated to power drive roller 17 rotation to pull paper 12 through nip 15 and to dispense a length of paper 12 from dispenser 10. Accordingly, motor 21 produces movement of paper 12 when current is supplied to motor 21 under control of controller 39 resulting in rotation of roll 1 1 in the direction of arrow 42.
  • the paper 12 length dispensed in each dispense cycle is approximately 12 inches, although the length can be set based on the preference of the party providing the dispenser 10 for use.
  • a representative proximity sensor 41 which may be used to detect the presence of a user's hand is described in U.S. Patent Application Serial No. 1 1/566,465 (Rodrian), the contents of which are incorporated herein by reference.
  • a contact switch (not shown) operated by a push button or the like (not shown) on housing 13 could be used in place of proximity sensor 41.
  • a battery 43 is preferably provided for powering components such as the motor 21, controller 39, proximity sensor 41, and indicator 45.
  • Indicator 45 is activated by controller 39 to provide the low-material indication in the illustrated example.
  • a preferred indicator 45 is a lamp.
  • a preferred lamp is a light-emitting diode (LED).
  • LED light-emitting diode
  • an audio emitter could be used to provide an audible signal indicative that dispenser 10 is in the low-material state.
  • Other indications such as controlling motor 21 to shorten or lengthen the sheet material dispensed in subsequent dispense cycles relative to the standard length (e.g., 12 inches), could be implemented.
  • a DC power source such as an AC-powered DC power supply, may be utilized in place of battery 43.
  • a support 47 is provided to support roll 11 in dispenser 10.
  • support 47 may include a yoke 49 attached in a suitable manner to housing 13.
  • Yoke 49 includes arms 51, 53 and roll holders 55, 57.
  • Arms 51 , 53 are preferably made of a resilient material so that they may be easily spread apart to insert roll holders 55, 57 into a core 59 of roll 1 1 , permitting free rotation of roll 1 1 on support 47.
  • a sensor 61 is provided on roll holder 57 to generate a signal when roll 11 is rotated on roll support 47.
  • the signal output by sensor 61 is referred to herein as a "sensor signal.”
  • Sensor 61 is operably connected to controller 39 and is powered by battery 43 or other DC power source.
  • the sensor signal is received by controller 39 during a time interval of roll 1 1 rotation, and controller 39 determines the roll 1 1 rotational speed from the sensor signal.
  • the rotational speed of roll 1 1 is identical to the rotational speed of core 59 and is referred to herein as core 59 speed.
  • Speed refers to distance (or angular displacement) traveled during a period of time.
  • Core 59 speed is data utilized by controller 39 to determine, or sense, the low-material state of dispenser 10 and to activate indicator 45, thereby alerting the attendant that roll 11 is nearly or fully depleted of paper 12 and must be replaced with a full roll 11.
  • the sensor signal output by sensor 61 during roll 11 rotation may also be used for the further purpose of recognizing roll 1 1, thereby permitting dispenser 10 operation with a roll 11 from an authorized source.
  • One such roll recognition system is as described in U.S. Patent No. 7,040,566 (Rodrian et al.), the contents of which are incorporated by reference. Operation of dispenser 10 with a recognized roll 1 1 advantageously permits use of paper 12 or other forms of sheet material which are optimized for use with the dispenser 10.
  • the recognition that sensor 61 may be used for both roll 1 1 recognition and as part of a low-material sensing system represents an opportunity to provide the useful low-paper sensing capability without the necessity of additional hardware providing an opportunity for an additional feature without an increase in product cost. Exemplary sensor 61 structure is described more fully below in connection with Figures 3-4 and 7 and the roll support structure 47 roll holder 57.
  • code 75 is a bar code capable of detection by sensor 61 for purposes of sensing a low-material state of roll 11 and/or roll 11 recognition.
  • Exemplary core 59 is preferably a hollow cylindrically-shaped tube including ends 67,
  • Core 59 may be manufactured in any suitable manner and of any suitable material.
  • core 59 is a cardboard core common in the paper-converting industry.
  • Core 59 consists of a helically-wound lamination of paper sheets.
  • Core 59 may be made of materials other than cardboard, including plastic and the like.
  • bar code 75 is located on core 59 inner surface 71. In the example, there are four repeated copies of bar code 75 on core inner surface 71. No particular bar code 75 quantity required.
  • sensor 61 is in a fixed position on roll holder 57 and bar code 75 is sensed by sensor 61 as roll 11 rotates.
  • each bar code 75 consists of a series of varying width bars 77 and spaces 79 which are the elements of bar code 75.
  • a relatively larger space referred to as a quiet zone 81 exists between adjacent copies of the bar code 75 for a purpose described herein.
  • Figures 8A and 9A include text indicating the location of the bars 77, spaces 79 and quiet zones 81 (abbreviated QZ). This exemplary form of bar code 75 is described in greater detail below in connection with Figures 8, 8 A, 9 and 9 A.
  • each bar code 75 is preferably printed on the paper used to form core 59 during core manufacture.
  • Bar code 75 on core 59 has a helical appearance consistent with the helical winding of the paper forming core 59.
  • This helical arrangement of bar code 75 is advantageous because it permits efficient manufacture of core 59 with each bar code 75 being uniformly positioned along the axial length of core 59 while using mass production processes commonly used in the sheet-material industry.
  • exemplary bar code 75 may be positioned: (a) in a helically-disposed pattern as shown in Figures 2-3 and 5-6, (b) concentrically about the center of the core 59 inner surface 71 along core end 69 (or end 67), or (c) along an edge surface 83 of roll 11.
  • Bar code 75 need not be printed on core 59 and could, for example, be provided in the form of an adhesive-backed tag affixed to core 59.
  • Figure 4 provides an exploded illustration of an exemplary roll holder 57 and sensor 61 supported thereon.
  • roll holder 57 includes cover 85 with an opening 86, sensor 61, hub 89, base 91, washer 93 and fastener 95.
  • Base 91 is secured by fastener 95 inserted through arm 53 eyelet 97.
  • Base 91 is in fixed-position relationship to arm 53.
  • Pins 96 secure sensor 61 to base 91 by means of a friction fit and are received into corresponding female openings (not shown) in cover 85 to secure cover 85 to base 91 also by means of a friction fit.
  • Sensor 61 is in
  • Hub 89 includes a neck 99 sized to be received in core 59 end 69 to support core 59 when mounted on yoke 49 and roll holders 55, 57. Hub 89 is rotates easily on base 91 for co-rotation with core 59 as roll 11 rotates within dispenser 10.
  • Roll holder 55 may be a mirror image of roll holder 57, but would not necessarily include a sensor 61.
  • sensor 61 includes sensor source 105 and sensor element 107.
  • Sensor source 105 is preferably a discrete infrared laser LED such as an Optek Technology brand OPV332 device.
  • Sensor element 107 is preferably a phototransistor device.
  • a suitable phototransistor 107 is an OP506B photo transistor also available from Optek Technology.
  • the sensor element 107 and sensor source 105 are mounted side-by-side on a converging optical axis in a plastic housing 108 directed toward sensor cover opening 86.
  • Sensor 61 is oriented such that sensor source 105 and sensor element 107 are fixed in place and spaced from core 59 inner surface 71. This arrangement orients sensor 61 to scan a bar code 75 during roll 11 rotation on roll holders 55, 57.
  • the sensor signal output by sensor apparatus 61 corresponding to bar code 75 is typically an analog voltage signal representative of the amount of IR radiation reflected from bar code 75 as the bars 77, spaces 79 and quiet zones 81 (e.g., Figures
  • the analog sensor signal is received by controller 39 and is digitized by analog-to-digital converter 1 11.
  • the analog signal corresponding to a bar code 75 is a time- varying voltage based on bar code 75 bar and space 77, 79, 81 elements. This time variation is used by controller 39 to determine the core 59 speed for purposes of sensing the low-material state as described below.
  • controller 39 then prevents proper operation of dispenser 10. For example, controller 39 could prevent powering of motor 21 as described in U.S. Patent No. 7,040,566.
  • dispenser 10 is shown with sensor 61 comprising a bar code sensor system with an optical emitter and detector (e.g., sensor source 105, sensor element 107), it is envisioned that other types of sensor apparatus 61 could be utilized to detect types of machine-readable indicia other than a bar code 75 associated with roll 11, provided that sensor 61 is capable of detecting roll 1 1 rotation during a dispense cycle.
  • Other suitable sensor apparatus 61 could include, for example, a magnetic sensor adapted to detect the presence of magnetic ink or other magnetic object on roll 1 1 or a capacitive field disturbance/proximity detector detecting objects embedded in roll 11.
  • FIG. 7 there is shown a circuit diagram of an exemplary control circuit and system which controls dispenser 10 operation.
  • the control system includes controller 39 and the related circuit components shown in Figure 7 including microcontroller 109.
  • Microcontroller 109 is programmed with software instructions for implementing the functions described in greater detail below.
  • Microcontroller 109 receives signals from proximity sensor 41 representing a request for a sheet of paper towel to be dispensed. Microcontroller 109 turns motor 21 "on" in response to signals output from proximity sensor 41 in this embodiment.
  • Microcontroller 109 includes an integrated analog-to-digital (A/D) converter 1 1 1 that is connected to a "motor signal" output from motor 21 both during powered motor 21 operation and when motor 21 armature 23 is coasting after current supply to motor 21 is deactivated by controller 39.
  • the motor signal from motor 21 is indicative of at least one of motor current and voltage.
  • the motor signal is also referred to herein as the motor current (Im) and the digitized motor signal is also referred to herein as the digitized motor current.
  • A/D converter 1 1 1 1 measures the motor signal digitally.
  • Figure 10 illustrates such an exemplary digitized motor signal.
  • A/D converter 111 further receives and digitizes the "sensor signal" output from sensor 61.
  • Microcontroller 109 employs the data collected by the A D converter 111 to detect the pulses in both (1) the digitized motor signal (i.e., digitized motor current) resulting from armature 23 rotational displacement and (2) the digitized sensor signal.
  • the digitized motor signal i.e., digitized motor current
  • Microcontroller 109 further determines the motor 21 speed during a time interval of motor armature 23 rotation based on the digitized motor signal pulses and determines the core 59 speed during a time interval of roll 11 rotation based on the detected sensor signal pulses.
  • motor 21 speed is determined using information in the motor signal
  • sheet material roll 11 speed is determined using information in the sensor signal in the example.
  • Microcontroller 109 compares the rotational speeds of the motor 21 and core 59 and activates the indicator 45 when the comparison reaches a threshold
  • This strategy provides for accurate sensing of the low-material state because the comparison is most preferably based on steady-state speeds of motor 21 and core 59, thereby avoiding potential errors associated with displacement-type detectors which may not control for supply roll 11 overspin resulting from inertia.
  • microcontroller 109 employs the data collected by the A/D converter 111 to detect the pulses in the digitized motor signal (i.e., digitized motor current) and turn the motor 21 "off once the required quantity of pulses have been detected.
  • microcontroller 109 may be configured to implement differing pulse detection techniques depending on the particular characteristics of the system in which it is employed.
  • An exemplary microcontroller 109 suitable for performing the functions described herein is a model number MSP430F2132 offered commercially by Texas Instruments, Inc.
  • Controller 39 includes a field effect transistor 113 connected to an activation output terminal 115 of the microcontroller 109 for activating the motor 21.
  • a resistor 117 is provided to ensure that the transistor 113 is deactivated after a reset of the microcontroller 109 before its I/O ports are initialized.
  • a resistor 119 limits short- term oscillation that may occur at the input of the transistor 113 when it is activated.
  • a capacitor 121 is coupled across the terminals of the motor 21 to reduce radiation of RF energy due to brush noise (commutator switching noise) in the motor 21.
  • a diode 123 is also provided across the motor terminals to suppress a voltage spike (Figure 10, pulse 151) that may occur when the motor 21 is turned off.
  • Controller 39 further includes a first current-sensing resistor 125 which is provided to generate a voltage proportional to the motor current when the motor 21 is activated through the transistor 113.
  • a second current-sensing resistor 127 bypasses the transistor 113 and generates a voltage proportional to the motor current when the motor 21 is turned off, and the first current-sensing resistor 125 is isolated by the transistor 113.
  • the resistors 127, 129 and capacitor 131 are provided to act as a low- pass anti-aliasing filter on the motor signal (i.e., motor current) input to A/D converter 111 at input terminal 132.
  • the resistors 125, 127, and 127 provide a speed-sensing apparatus for producing the motor signal indicative of motor 21 speed.
  • the motor signal (i.e., motor current) is received by A/D converter 111 and is digitized by A/D converter 111 for determination of motor 21 speed by microcontroller 109.
  • sensor 61 is connected to microcontroller 109 of controller 39 as follows.
  • Sensor source 105 (a discrete infrared laser LED in this example) is connected to battery 43 and transistor 136.
  • Transistor 136 in combination with resistors 135 and 137 form a constant current source connected to output terminal 133 of microcontroller 109 to activate the source 105.
  • Sensor element 107 (a)
  • phototransistor in this example is connected to battery 43 and A/D converter 111 of microcontroller 109 through resistor 139.
  • the analog sensor signal output from sensor element 107 is a current that passes through resistor 139 to generate an analog voltage signal that is applied to the A/D converter 1*11 input terminal 140.
  • This analog voltage signal is digitized by A/D converter 111 for determination of core 59 speed by microcontroller 109.
  • Indicator 45 is connected to controller 39 at an activation output terminal 141 of the microcontroller 109 for activating the indicator 45.
  • a resistor 143 of controller 39 is provided to limit the current that flows through indicator 45.
  • Battery 43 powers operation of controller 39, motor 21, indicator 45, and sensor 61.
  • Figures 8-9A illustrate a preferred form of bar code 75 applied to the inside of core 59 of roll 11 , but as each code 75 would appear in an unrolled two-dimensional state.
  • Figure 8 illustrates the inner paper sheet of core 59 in a two-dimensional state.
  • Figure 8 A illustrates an enlarged region of Figure 8.
  • Figures 8 A and 9 A are labeled so that each bar 77 is indicated as one of Bar 1 through 6 and each space 79 is designated as one of Space 1 through 5.
  • bar code 75 is repeated such that four copies of bar code 75 are printed on core 59 as illustrated in Figure 8. Between each copy of bar code 75 is the relatively wider space quiet zone 81 region, referred to as a QuietZone in the logic flow diagrams of Figures 11 A- 12.
  • each copy of bar code 75 consists of six bars 77 (Bar 1 through Bar 6) and five spaces 79 (Space 1 through Space 5).
  • Quiet zone 81 (QZ) is located between the copies of bar code 75.
  • bar code 75 is contained within the relative widths of the bars 77 (Bars 1-6) and spaces 79 (Spaces 1-5).
  • Bar code 75 in Figure 8 therefore represents the six-digit binary number 01 1110 as indicated on Figures 9-9A. Since the bar code is symmetrical in this embodiment of bar code 75, there are only eight (2 3 ) possible unique values of the three-digit binary number (half of the six-digit bar code 75).
  • Figures 9 and 9A show the digitized sensor signal resulting from roll 1 1 rotation once the sensor signal output from sensor 61 is digitized by A/D converter 1 1 1 and is processed by bar-code-detection logic 290 on board microcontroller 109 as shown and described below in connection with Figure 1 1C.
  • Exemplary bar code 75 is superimposed in Figures 9 and 9A to illustrate the digitized sensor signal portions corresponding to the bar code 75 bars 77 (Bars 1-6), spaces 79 (Spaces 1-5) and
  • Figures 1 1 A through 1 ID illustrate one embodiment of a low-material sensing system for use with exemplary paper-towel-type sheet material dispenser 10.
  • Figures 1 1 A through 1 ID are flow diagrams of the logic of a programmed set of instructions in microcontroller 109 firmware which control the material dispensing and low- material sensing processes.
  • Figure 1 1 A illustrates the logic of the main control loop 200.
  • a portion of the logic of main control loop 200 generates a value for a variable which represents the speed of motor 21 armature 23, also referred to herein as motor 21 speed.
  • Motor 21 speed is subsequently used in Figure 1 ID to determine whether the low-material state exists.
  • the motor-speed determination is made utilizing motor pulses which occur while the motor 21 is coasting.
  • the motor-speed determination is made utilizing motor pulses which occur while the motor 21 is coasting.
  • 21 speed determination may be made utilizing motor 21 pulses generated while current is supplied to the motor 21.
  • Figure 1 IB illustrates an embodiment of the interrupt logic 240 which operates when an interrupt is enabled (element 213) once in each dispense cycle within main control loop 200 of Figure 11 A.
  • the enabling causes an interrupt event to occur repeatedly every 50 microseconds ( ⁇ $), until the interrupt is disabled (element 227) at the end of a dispense cycle.
  • Each interrupt event (element 241) causes execution of the logic described in Figure 1 IB.
  • motor pulses are detected during a time increment for the motor 21.
  • Speed determination and bar-code- detection logic 290 in Figure 1 1 C occurs for determining the speed of roll 1 1 and core 59 rotation during a time increment, also referred to herein as core 59 speed.
  • Figure 1 1C illustrates an embodiment of bar-code-detection logic 290 which operates within interrupt logic 240 ( Figure 1 IB, enabled at element 277) to generate information representing the relative widths of the bars and spaces of bar code 75 in core 59 of roll 1 1. This information is subsequently used in Figure 1 ID to determine the speed of roll 1 1 and core 59 rotation.
  • Figure 1 ID illustrates an embodiment of the bar-code-analysis logic 340 with which the bar code information produced by bar-code-detection logic 290 ( Figure 1 1C) is analyzed (a) to generate a measure of core 59 speed, (b) to compare this core 59 speed with the motor 21 speed value generated by main control loop 200 in Figure 11 A, and (c) to activate indicator 45 indicative of the low-material state occurring when roll 1 1 is near depletion.
  • boxes with curved sides are start or termination elements and represent entry or exit points within the logic flow.
  • Rectangular boxes, such as logic element 203 represent functional elements within the logic flow.
  • Diamond-shaped boxes, such as logic element 207 represent decision elements in the logic flow. In each decision element, two logic flow paths emerge, one for a "YES" decision and one for a "NO" decision.
  • Small circular logic elements, such as logic element 205 are connection elements in which the various logic flow paths which are connected at such logic elements are joined to continue the flow from the common point of such connection element. The direction of logic flow is indicated by arrowheads on the logic flow paths.
  • bold text is used to represent variables and non-bold text is used to represent quantities which are constant within the operation of the logic flow.
  • main control logic 200 is (a) to initialize many of the variables used in microcontroller 109, (b) to capture a user- request for a sheet of paper towel 12 thereby initiating a dispense cycle, (c) to turn motor 21 "on” and “off to dispense the proper length of paper towel 12, (d) to determine a value of motor armature 23 speed (for use in determining whether or not the supply of paper towel 12 on roll 11 is nearly depleted, i.e., the low-material state), and (e) to manage the other portions of logic which are used to control dispenser 10 as illustrated in Figures 1 lB-1 ID and described in detail below.
  • main control logic 200 begins at element 201 with controller 39 being powered up.
  • a start-up routine is carried out which initializes the I/O pins and the devices connected to microcontroller 109 and resets low-material indicator 45.
  • part of the function of controller 39 is to control the length of material dispensed during each dispense cycle.
  • an initial value Initial Coasting Pulses representing the length of material dispensed during coasting (after the deactivating of motor 21) is loaded into the variable
  • dispenser 10 start-up routine is complete in element 203, dispenser 10 is ready for detection of a user's hand, indicative of a user request for a sheet of paper towel 12.
  • decision element 207 detection by proximity detector 41 of a user's hand adjacent dispenser 10 is determined. If a hand is detected, a "YES” decision is made within decision element 207 and the logic flow continues to element 209. If the presence of a hand is not detected, a "NO” decision is generated and the logic flow continues to interrogate hand-detection in a short logic loop around decision element 207 until a "YES" decision is generated.
  • BarWidth[] in functional element 209 and a number of variables in functional element 211 is a one-dimensional list (vector) of values which, when loaded, contains time intervals which represent the widths of the spaces 79 (Spaces 1 - 5) in bar code 75.
  • BarWidth[] is a one-dimensional list (vector) of values which, when loaded, contains time intervals which represent the widths of the bars 77 (Bars 1-6) in bar code 75.
  • Int_Count is a variable which is used to count the number of interrupts encountered. In this embodiment, interrupts occur every 50 ⁇ and provide the time base information for controller 39.
  • MotorPulses is a variable which is used to count electrical pulses generated by motor 21 as described above.
  • PulseLevel of element 211 is a variable which is either a logical "0" ("low” indicates the absence of a motor pulse) or a logical "1" ("high” indicates the presence of a motor pulse).
  • PreviousLevel is a variable which is set in the logic to the previous value of
  • BC_Index is a pointer variable which is used to indicate which entry in the BarWidth[] and Space Width[] arrays is being used at a point in time within the logic flow.
  • variable BarCodeTimer is set to 0.
  • BarCodeTimer is a counter variable which causes execution of the logic 290 of Figure 11C once every ten, 50 microsecond interrupts in elements 273, 275 and 277.
  • the logic 290 of Figure 11C is executed every 10 * 50 microseconds, which is once every 500 microseconds.
  • main control loop 200 enables the 50 ⁇ interrupt timer allowing interrupts to occur, interrupting the logic flow every 50 ⁇ when enabled.
  • controller 39 activates the supply of current to motor 21 in element 215, beginning the dispensing of a paper towel 12.
  • a preset length of paper towel is dispensed and the preset length of towel is represented by pulses generated by motor 21 both while motor 21 is powered and while it is coasting after controller 39 deactivates current supply to motor 21.
  • decision element 217 the logic determines whether the motor 21 has been activated sufficiently to dispense the preset length of towel 12 in the dispense cycle.
  • motor 21 is deactivated when counted motor 21 pulses during motor operation equal a value representing pulses required for a full sheet minus coasting pulses from the preceding dispense cycle.
  • the preset length of paper towel to be dispensed is the constant Sheet Length Pulses. While motor 21 is being powered, the variable MotorPulses is used to count (within interrupt logic 240 of Figure 1 IB) the number of motor pulses which occur during this motor-powered period. Thus, MotorPulses represents how much paper towel has been dispensed during powered motor 21 operation.
  • the variable CoastingPulses in element 217 is also a counter- timer, used to represent the amount of towel which is dispensed after current supply to motor 21 is deactivated.
  • the CoastingPulses value used during a dispense cycle to estimate the length of towel dispensed is the value stored in microcontroller 109 memory from the preceding dispense cycle.
  • decision element 217 the variable MotorPulses is compared with the preset constant Sheet Length Pulses minus CoastingPulses to determine if motor 21 should be deactivated. As long as the decision is "NO" in decision element 217, the logic flow remains in a short logic loop around decision element 217 while motor 21 is powered and the variable MotorPulses is incremented in interrupt logic 240 ( Figure 1 IB) during interrupts every 50 ⁇ in element 213 ( Figure 1 1 A). The value of
  • MotorPulses increases as the length of paper towel 12 pulled through nip 15 by motor- powered operation of drive roller 17 increases.
  • MotorPulses is reset to 0, initializing the value of MotorPulses which will then be used to determine the value of CoastingPulses for the next dispense cycle.
  • motor 21 speed is next determined once current to motor 21 is deactivated by controller 39 and a fourth motor pulse has been detected.
  • motor 21 speed is the steady-state speed determined once motor 21 is coasting. During coasting, motor 21 behaves as a generator. Motor 21 speed is determined by reference to the three pulses 153, 155, 157 following a transition pulse
  • Figure 10 is a graph illustrating pulses in a digitized motor signal (i.e. , the digitized motor current) used to determine motor 21 speed in this embodiment.
  • Figure 10 illustrates pulses during powered operation (interval 159) and after current to motor 21 is deactivated when motor 21 is coasting (interval 161) during the 50 ⁇ interrupts occurring while the interrupt is enabled.
  • Figure 10 shows the digitized motor signal measured in volts across current-sensing resistor 125 when motor 21 is activated (interval 159) or across resistor 127 when current to motor 21 is deactivated (interval 161).
  • the motor pulse which is generated immediately after depowering of motor 21 may provide unreliable time information. Consequently, this embodiment of controller 39 discards transition pulse 151 and uses the three motor pulses 153, 155, 157 during intervals 159 and 161 immediately after transition pulse 151, generated while the motor 21 is coasting, to provide the time information used to compute MotorSpeed.
  • These three coasting pulses 153, 155, 159 are selected by the short logic loop around decision element 221 which tests the number of pulses which have occurred after motor depowering by comparing the variable MotorPulses, incremented in interrupt logic 240 ( Figure 1 IB), to the number 3.
  • functional element 225 After the variable MotorSpeed has been set, decision element 225 and the short logic loop around it are used to determine when the speed of motor 21 has slowed sufficiently to estimate how far it has coasted after depowering.
  • the variable PulsePeriod is longer than 200 milliseconds, the variable CoastingPulses is set in functional element 227 to the number of motor pulses which have occurred during coasting for use during the next dispense cycle to determine paper towel length. At this point (functional element 227), the 50 ⁇ interrupt is also disabled.
  • the main control logic 200 branches to the bar-code-analysis logic 340 of Figure 1 ID.
  • functional element 231 provides a delay for a preset time to prevent dispenser 10 from dispensing another length of towel 12 immediately after completing the previous dispense cycle. The delay is provided to prevent repeated dispense cycles which could result in waste of the paper towel 12.
  • the preset time choices shown are 0, 1 , and 2 seconds but other preset values for the delay may be used.
  • the logic flow then is directed back to functional element 207 of Figure 11 A to wait for the next detection of a user's hand representing the next request for a paper towel 12.
  • Interrupt logic 240 provides the information for dispenser 10 control which is based on time.
  • the control logic is interrupted every 50 ⁇ 5 and the functions which are carried out are (a) the detection and timing of motor pulses ( Figure 1 IB) and (b) the measurement of bars and spaces in bar code 75 ( Figure 1 IB element 277 and Figure 1 1C).
  • bar-code-detection logic 290 in Figure 1 1C is performed periodically at the end of certain 50 ⁇ interrupt logic 240 cycles.
  • Int_Count provides a count of the number of 50 ⁇ time intervals (and thus a measure of time) during a dispense cycle since it is reset to 0 at the beginning of each dispense cycle. This count is followed in functional element 245 by a measurement of the motor signal (i.e., the motor current) and placing the result into the variable
  • the motor signal (i.e., the motor current) is measured by A/D converter 1 1 1, and such measurements are used to identify pulses in motor signal (i.e., the motor current) which provide the measurement of distance traveled by motor armature 23.
  • the filter 245 also includes filtering the digital stream of motor signal (i.e., the digitized motor current) measurements from A D converter 1 11 with a low-pass filter.
  • the new filtered value of the variable MotorCurrent(i+l) at time “i+1” is set equal to a weighted sum of the previous filtered value of the variable MotorCurrent(i) at time “i” and the new measured value of MotorCurrent(i+l).
  • Use of such a low-pass filter is not required but may improve motor pulse detection.
  • the pulses e.g., pulses 153, 155, 157) in the digitized motor signal ( . e. the digitized motor current) shown in that figure correlate with the rotation of motor armature 23 and thus can be used to infer motor 21 speed.
  • These pulses e.g., pulses, 153, 155, 157) have rising and falling edges which define the pulses.
  • a rising edge of pulse 155 is identified by reference number 167 and a falling edge of pulse 155 is identified by reference number 169.
  • a calculation of the derivative of the motor signal i.e. , the motor current
  • MotorCurrentDerivative is used to sense the rising and falling edges (e.g., edges 167, 169) of such pulses (pulses 153, 155, 157).
  • a "boxcar" derivative calculation is performed using the eight most recent measurements values of MotorCurrent, as follows: MotorCurrentDerivative is equal to the sum of the four most recent values of MotorCurrent minus the sum of the previous four values of MotorCurrent.
  • interrupt logic 240 calculates the elapsed time (PulsePeriod) since the last motor current pulse in functional element 249.
  • Interrupt logic 240 then proceeds to decision element 251 in which the value of the MotorCurrentDerivative is compared to a preset threshold Motor Edge High Limit.
  • Motor Edge High Limit may have a value on the order of 50.
  • MotorCurrent and MotorCurrentDerivative are values of A/D counts, and in this embodiment, A/D converter 1 11 has a full-scale of 1023 counts for a full-scale voltage of 1.5 volts.
  • a rising edge e.g., rising edge 167
  • decision element 251 If a "NO" decision is reached in decision element 251, a similar comparison is made in decision element 265 looking for falling edges (e.g., falling edge 169) of motor pulses (pulses 153-157) using a preset threshold Motor Edge Low Limit, which in this embodiment may have a value on the order of -50.
  • interrupt logic 240 proceeds to set a variable PulseLevel to "1" (logical high) to indicate that a rising edge (e.g., rising edge 167) has been found in the motor current.
  • decision element 255 the logic flow branches depending on whether the previous value of PulseLevel (called PreviousLevel) is a "0" or a "1" (logical low or high). If the decision is a "YES” (i.e. , this is a new pulse), interrupt logic 240 proceeds to the following steps: (a) MotorPulses is incremented by 1 in functional element 257 to provide a count of motor pulses; (b) a variable TimeOfLastPulse is set to the time value Int Count in functional element 259; (c) the time variable
  • TwoPulsePeriods is set to the sum of the two most recent values of PulsePeriod (PulsePeriod + PreviousPeriod) in element 261; and (d) the variable PreviousPeriod is set to the current value of PulsePeriod in element 263.
  • connection element 268 is the same point (connection element 268) at which the logic would have proceeded if a "NO" decision had been reached at decision element 255 (i.e., the rising edge 167 is not in a new pulse 153).
  • Connection element 268 is also reached when the logic flow passes through decision element 265 looking for falling edges within the motor signal (i.e., the motor current).
  • decision element 265 if a falling edge (e.g., falling edge 169) is detected (a "YES" decision in element 265 based on comparison of MotorCurrentDerivative with the threshold Motor Edge Low Limit), the variable PulseLevel is set to "0" (logical low) in functional element 267. If no falling edge is detected in decision element 265, no further action is taken and the logic proceeds to functional element 269.
  • a falling edge e.g., falling edge 169
  • the digitized motor signal i.e. the digitized motor current
  • MotorCurrent is continuously analyzed to detect all rising and falling edges (e.g., edges 167, 169).
  • transition pulse 151 is detected and treated as a "normal" pulse.
  • the pulse period (motor speed) associated with this transition pulse 151 is ignored because more than 3 pulses (element 221) must be detected after the motor 21 is turned off before the pulse period information is used to determine the motor speed in element 223 which follows.
  • PreviousLevel is set to the current value of PulseLevel in order to capture both the current and previous time periods between pulses.
  • the variable TwoPulsePeriods is computed in functional element 261 to then be used in functional element 223 in main control logic 200 ( Figure 11 A).
  • BarCodeTimer serves as a timer to trigger bar-code-detection logic 290 in Figure 1 1C.
  • decision element 273 After every 10 interrupt cycles (or 500 ⁇ 8), decision element 273 redirects interrupt logic 240 to branch to the bar-code-detection logic 290 of Figure 1 1C in functional element 277.
  • element 275 the variable BarCodeTimer is initialized to 0 in preparation for the next such branching.
  • Termination element 279 is entered either from decision point 273 (after a "No" decision) or from element 277. In termination element 279, the interrupt logic 240 returns to the point from which it was triggered.
  • FIG. 11C there is shown the logic for detecting bar code 75 within core 59 of roll 1 1.
  • the detected bar code information is loaded into arrays BarWidth[] and Space Width[] and is used in the logic 340 of Figure 1 ID to determine the rotational speed of core 59 for purposes of activating low-material indicator 45.
  • Bar-code-detection logic 290 is entered at element 291 and proceeds in functional element 293 to measure the sensor signal from bar code sensor 61 and place the measured value in the variable BarCodeSignal. This digitized measurement is made by A/D converter 1 1 1 in a manner similar to the measurement of motor current.
  • BarCodeSignal has a rising edge 171 at the beginning of a space 79 and a falling edge 173 at the beginning of a bar 77.
  • Figures 9 and 9A illustrate one example of a digitized signal from sensor 61 corresponding to bar code
  • Figures 9 and 9 A illustrate a representative exemplary rising edge 171 and a representative falling edge 173.
  • decision element 297 the logic seeks to detect bar 77 to space 79 transitions in bar code 75 within the digitized sensor signal output from A/D converter 1 1 1. This edge-detection process is similar to the measurements related to motor current.
  • the bar-code-detection logic 290 proceeds to look for edges in BarCodeSignal in decision element 297, in which the current value of BarCodeSignalDerivative is compared to a preset threshold Edge High Limit.
  • Edge High Limit may have a value on the order of 70, and in similar fashion in decision element 313, the value of threshold Edge Low Limit may be on the order of -70. If in decision element 297, a rising edge ⁇ e.g., rising edge 171) is not detected by the comparison with threshold Edge High Limit, then bar-code-detection logic 290 proceeds to look for a falling edge (e.g., falling edge 173) in functional element 313. If no falling edge is detected in functional element 313, then bar-code-detection logic 290 ends at termination element 327, and the logic flow returns to interrupt logic 240 at functional element 277 in Figure 1 IB.
  • Decision element 299 is entered if a rising edge is detected in decision element 297.
  • decision element 299 if the value of a variable DerivativeLevel is not -1, the logic flow branches around functional elements 301, 303, and 305. A value of
  • DerivativeLevel of 1 indicates that a rising edge has been detected, and a value of -1 indicates that a falling edge has been detected.
  • Decision element 299 examines the previously-set value of DerivativeLevel to see if a falling edge had been detected the last time the variable DerivativeLevel was set. If a rising edge is detected in decision element 297 and a rising edge had also been detected previous to such detection in element 299, then a branching around functional element 301, 303, and 305 occurs.
  • decision element 299 if the value of DerivativeLevel is -1 , then the combination of the current rising edge (detected in decision element 297) and the most recent falling edge (confirmed in decision element 299) means that the leading and trailing edges of a space in bar code 75 have been detected. Then, in functional element 301, the value of Deri ativeLevel is set to 1 to indicate the start of a space (end of a bar).
  • array entry Space Width[BC_lndex] is set to the time interval BarStart - BarEnd.
  • BarStart and BarEnd used in the calculation of Space Width[BC_Index] have been set during previous iterations of barcode-detection logic 290.
  • the timer-counter variables BarStart and BarEnd are set at points in bar-code-detection logic 290 which are downstream of functional element 303 and will be discussed below.
  • the result of functional element 303 is that the time interval representing the width of a space in bar code 75 is loaded into one entry of the array Space Width[].
  • index pointer BC_Index is then incremented by 1 in functional element 305 in preparation for loading the next entry into the array BarWidth[].
  • Decision element 307 determines if the value of BarCodeSignal Derivative is a local maximum by comparing its value with its previously-saved value
  • PreviousDerivative If BarCodeSignalDerivative is found to be greater than its previous value, then the value of time BarEnd is set to the value of Int Count in functional element 309, and the value of BarCodeSignalDerivative is saved as PreviousDerivative. This is the determination that a bar 77 has ended and a space 79 has started in the sensing process as bar code 75 moves past sensor 61. Put another way, a bar-to-space transition (end of a bar 77 which also is the start of a space 79) or a space-to-bar transition (end of a space 79 which is also the start of a bar 77) occurs at a time equal to the value of the Int_Count variable. (The Int Count is incremented every 50 microseconds.) The time difference of two edges determines the width of a bar 77 or the width of a space 79.
  • Bar-code-detection logic 290 ends from decision element 307 or functional element 31 1 , returning logic flow to the end of interrupt logic 240.
  • BarCodeSignalDerivative is tested against a preset threshold Edge Low Limit in decision element 313 to determine if a falling edge has been reached in BarCodeSignal. If no such edge is detected in decision element 313, bar-code- detection logic 290 ends, returning logic flow to the end of interrupt logic 240.
  • bar-code-detection logic 290 proceeds through logic elements 315, 317, 319, 321 , 323, and 325 in a fashion directly similar to logic elements 299, 301, 303, 305, 307, 309, and 31 1.
  • BC Index is not incremented (no functional element similar to functional element 305 exists).
  • array BarWidthf] sequentially contains each bar width
  • array Space Width[] sequentially contains each intervening space width
  • the pair of arrays BarWidth[] and Space Width[] contain a complete representation (widths represented by time in 50 ⁇ 8 counts) of bar code 75.
  • array values range from the low 10's to low 100's.
  • the bar-code-detection logic 290 of Figure 11C runs whenever it is triggered at functional element 277 ( Figure 1 IB) within interrupt logic 240.
  • Interrupt logic 240 is disabled in functional element 227 in main control logic 200 when it is determined that a dispense cycle has ended in decision element 225. Then, in functional element
  • the bar-code-analysis logic 340 of Figure 1 ID is triggered at the end of a dispense cycle.
  • Figure 1 ID illustrates exemplary bar-code-analysis logic 340.
  • the function of bar-code-analysis logic 340 is (a) to use the data in arrays BarWidth[] and
  • bar-code-analysis logic 340 begins with element 341. Then, in functional element 343, a variable Search lndex is initialized to 1, and a variable QuietZone_Index is initialized to 0. These two indices are pointers used in the analysis of the bar code data in the arrays.
  • BC Index is greater than 2.
  • the value of BC Index at this point in the logic flow is equal to the number of bars 77 which have been loaded into array BarWidth[].
  • a value of BC Index less than 2 indicates that an insufficient number of bars 77 have been detected to make a core 59 speed determination. If insufficient bars 77 have been detected in element 345, bar-code-analysis logic 340 ends at termination element 367, returning the flow of logic to main control logic 200 which proceeds to functional element 231 ( Figure 11A), providing a preset delay before returning to the small logic loop around decision element 207 to wait for the next detection of a user and a request for a towel to be dispensed.
  • the logic moves to decision element 347 if the value of BC_Index is greater than 2 as determined in element 345.
  • decision element 347 a determination is made regarding whether or not the current space (i.e., the space width, expressed in 50 ⁇ time counts, in Space Width[] pointed to by the current pointer value Search lndex) is a QuietZone 81.
  • a QuietZone 81 is the wider space between neighboring copies of bar code 75, and in this embodiment, this determination is made by comparing the width of the current space to the sum of one- and-a half times the width of the next space plus the width of the next bar in the arrays.
  • the exemplary QuietZone 81 width is 50% wider than the width of the adjacent bar 77 plus the width of the adjacent space 79 and this is the minimum width of the QuietZone 81 in the example.
  • Other suitable comparisons may be made, such as simply with a preset threshold width which would be sufficient to define a QuietZone 81.
  • Logic elements 347, 349, 351, 353, and 355 form a loop which is configured to identify a QuietZone in bar code 75 by identifying the first full QuietZone
  • Decision element 349 identifies full Quiet Zone 81 based on the specific configurational rules of bar code 75 as described above, including the fact that there are six bars 77 between QuietZones 81 in the example.
  • QuietZone 81 is identified in functional element 347, if it is found in decision element 349 to be six entries away in the array Space Width[], then it is determined that the repeated bar codes 75 are being properly sensed and QuiteZone 81 has already been identified. In this case, the value of QuietZone lndex is not set to a new value and the reading of the array SpaceWidth[] continues until the full number of spaces has been searched for QuietZones 81. This determination is made in decision element 355.
  • the bar-code-analysis logic 340 continues to decision element 357 in which, if the value of QuietZone lndex is not greater than 0, no calculation of core 59 speed is done since a value of 0 indicates that no full QuietZone 81 was found. If full QuietZone 81 has been found, then decision element 359 is used to filter out situations in which there is insufficient data in the arrays to make a good estimate of the core 59 speed, i.e., there are not at least two pairs of bars and spaces following the selected QuietZone 81.
  • Functional element 361 calculates the variable CoreSpeed if sufficient data is available as determined in element 359.
  • the value of the variable CoreSpeed is set to the sum of the time widths of the first bar 77 (Bar 1 in Figure 8A) plus the first space 79 (Space 1 in Figure 8A) immediately after selected QuietZone 81. Because of the requirements on the embodiment of bar code 75 described above, this sum represents a known distance, namely, a narrow bar (logical "0") is followed by a wide space or a wide bar (logical "1”) is followed by a narrow space.
  • the comparison in decision element 363 is equivalent to determining whether or not CJM S is greater than a preset ratio threshold. That is, the determination is whether or not the speed C s of core 59 has increased relative to the speed M s of motor armature 23 above a preset ratio threshold.
  • the ratio CoreSpeed/MotorSpeed is compared to a preset ratio threshold to determine whether roll 1 1 of paper towel is near depletion and ready to be replaced.
  • the preset ratio threshold is shown as 7.5. The value of this ratio threshold depends on many factors in both the hardware and software of the embodiment of the invention, and the ratio threshold is chosen accordingly to indicate that roll 11 is nearly depleted and in a low-material state.
  • indicator 45 is activated to provide a low-material indication if the speed ratio CoreSpeed/MotorSpeed has reached the preset ratio threshold in decision element 363. If not, no such signal is enabled.
  • the bar-code-analysis logic 340 ends, and the flow of logic returns to main control logic 200 at functional element 231 ( Figure 11A) awaiting detection of the user's hand indicative of the next request for a towel at decision element 207 as described above.
  • the extra bar-and-space pair required by decision element 359 simply ensures that the bar 77 and space 79 used for the speed calculation are not the very last bar 77 and space 79 measured.
  • Figure 12 illustrates an alternative embodiment of the inventive low-material sensing system which utilizes motor pulses generated while motor 21 is powered. Such pulses are labeled with reference number 159 in Figure 10.
  • the alternative main control logic 200A of Figure 12 replaces main control logic 200 of the embodiment just described.
  • Figure 12 is used in conjunction with the logic of Figures 1 IB through 1 ID and in conjunction with bar code 75 as described in Figures 8 and 8A.
  • similar logic elements are identified using the same reference numbers as in Figure 11 A.
  • Alternative main control logic 200A proceeds in the same manner as described with respect to main control logic 200 in Figure 11 A except that the determination of motor speed is made using the variable TwoPulsePeriods in functional element 223 based on a value of such variable measured just prior to motor 21 being deactivated in functional element 219. All other logic elements of alternative main control logic 200A operate as previously described.
  • the strategy described herein facilitates accurate determination of the low- material state.
  • One factor contributing to such accuracy is that the motor 21 speed and core 59 speed determinations may be made during steady-state motor 21 operation and roll 11 rotation, thus avoiding potential inaccuracy associated with an angular displacement measurement system which may not account for supply roll 11 overspin resulting from inertia.
  • the present strategy is most preferably implemented by obtaining motor 21 speed and core 59 speed at different times in a dispense cycle.
  • Motor 21 rotational speed is preferably obtained from motor 21 armature 23 rotation pulse data during the "motor coasting" portion of a dispense cycle, immediately after current to motor 21 is deactivated when the motor is at steady-state operation.
  • well-defined pulses 153, 155 and 157 can be identified in the digitized motor signal as illustrated in Figure 10. These prominent coasting pulses 153, 155, 157 are well- suited for detection to determine motor 21 speed determination and yield accurate measurements of motor 21 speed.
  • Supply roll 11 rotational speed is best determined from bar code data captured during the "motor on" portion of a dispense cycle when drive roller 17 pulls paper 12 through nip 15 and rotates roll 11.
  • Such core 59 speed information represents steady- state roll 11 rotation which yields accurate core 59 speed information.
  • the accuracy of the motor 21 speed and core 59 speed information provides for a reliable indication of the low-material state.

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Abstract

L'invention porte sur un appareil, des systèmes et des procédés de délivrance d'un matériau en feuille (12) à partir d'un rouleau (11), comprenant un système de détection de quantité presque épuisée de matériau. Le système de détection de matériau presque épuisé délivre une indication lorsque le matériau en feuille (12) approche de l'épuisement ou est épuisé afin que le rouleau de matériau en feuille épuisé (11) puisse être remplacé par un rouleau neuf. Le système de détection de matériau presque épuisé détermine que le matériau en feuille (12) est épuisé ou presque épuisé par comparaison de la vitesse de rotation du rouleau de matériau en feuille (11) à partir duquel le matériau en feuille (12) se déroule avec la vitesse du moteur (21) générant le mouvement du rouleau de matériau en feuille (12) lorsque de l'énergie est délivrée au moteur (21). La vitesse du rouleau de matériau en feuille (11) augmente au fur et à mesure que le matériau (12) se déroule, alors que la vitesse du moteur (21) reste relativement constante. Une indication de matériau presque épuisée est délivrée lorsque la comparaison approche d'un seuil représentatif de l'état de matériau presque épuisé.
PCT/US2009/006131 2009-11-16 2009-11-16 Distributeur avec système de détection de quantité presque épuisée de matériau WO2011059423A1 (fr)

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EP09756869.5A EP2501267B1 (fr) 2009-11-16 2009-11-16 Distributeur avec système de détection de quantité presque épuisée de matériau
ES09756869.5T ES2584933T3 (es) 2009-11-16 2009-11-16 Dispensador con sistema de detección de poca cantidad de material

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Publication number Priority date Publication date Assignee Title
WO2014093192A1 (fr) * 2012-12-11 2014-06-19 Georgia-Pacific Consumer Products Lp Distributeur ayant plus d'un état d'entraînement de sortie
US20220160555A1 (en) * 2018-01-03 2022-05-26 Tranzonic Companies Apparatus and method to dispense sanitary hygiene products

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EP2501267B1 (fr) 2016-06-29
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