MXPA00010586A - Optical vend-sensing system for control of vending machine - Google Patents

Abstract

For ensuring that a vending machine motor will continue to operate until a product has descended through a vending space or an established time interval has elapsed, an optical beam is established across the vend space through which a product must drop. A change in beam intensity is detected. By preference infrared light is emitted at one focal point of an elliptical reflector, and detected at the other focal point. The light is emitted in pulses in the preferred embodiment, and the optical sensing system has automated calibration and error detecting functions.

Description

OPTICAL SALES DETECTION SYSTEM FOR CONTROL OF A VENDING MACHINE BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION The present invention pertains to a machine that supplies objects and detects the objects supplied with an optical detector, and more particularly with an optical detection detection system and a vending machine having an optical detection detection system.

DESCRIPTION OF THE RELATED TECHNIQUE In a typical sales machine with the front glass, the user of the machine observes a cabinet on the front of glass, with a selector panel located on the side of the glass. Through the glass, you can see an array of items, typically packaged snack foods arranged in horizontal columns which extend horizontally in a direction from the front to the back in the deep, with a plurality of columns in each of the levels separated vertically. In each level, the articles Ref: 124204 are packed between adjacent turns of respective spirals arranged in one or two to one column. Each spiral has a rod projecting backwards, axially central, in its rear part which is plugged into a mandrel of a respective motor assembly mounted to the rear of a tray when the user establishes the payment requirement in the machine and performs the desired selection on the selector panel, the spiral or spirals for the respective column begin to rotate causing all packaged items received between the spiral turns in the column to advance. If the vending machine is functioning properly, the respective scroll or spirals rotate sufficiently to cause the front packed article in the respective column to be transported far enough forward so that the package loses support that is provided from the bottom by a tray respective, and falls past the front of the respective shelf, through a sales space between the front parts of the columns and the rear of the glass front, in an outlet tank, from which the user can recover it, typically by temporarily pushing a normally closed door, articulated at the top. Again, if the machine works properly, the respective spiral or coils stop rotating by the respective motor assembly before the next container in the line, which is now turned the front article in the respective column by mistake, is transported so far forward so that it also falls from the tray downwards, through the sales space and is considered sold without having made the necessary payment. Various unplanned phenomena can occur, and the possibility and probability of their presentation complicates the design of sales machines with the glass front. It is important that users, when making the necessary payment, are reliably provided with the product they have selected without any deficiency or bonus, and without any need, or apparent desire to make an unusual effort, or in a way that the user automatically provide a return of payment or the opportunity to make another selection. The spatial orientation of containers and the rolling of containers, the current distribution of the contents of a container, the unusual fall of the container through the sales space, an empty package in a spiral and similar factors can cause an error in the sale, particularly if the machine is one in which the spiral will rotate through only a predetermined angular distance for a selected product, or in the package will be sold, depending on how much it falls, and can deflect a detector what which means finishing the rotation of the spiral or respective spirals upon detection that the container has been provided. Many vending machines with glass front are modularly constructed, so that the number of vertically separated rows of product columns or the number of columns separated laterally by row can change either at the moment when the machine is ordered by its supplier or at the place of sale, or in both places . This fact also complicates the fact of providing a reliable sale, particularly if columns are added and suppressed and if detectors need to be added and suppressed and ensure that the detectors are properly positioned and functioning correctly. The addition of detectors also increases the cost. It is known in the art to provide an emitter and detector which provide a beam in a confined space through which the product sold will fall. However, there is a certain probability that the falling product, through its circumstantial orientation does not interrupt the beam or that it apparently does not interrupt the beam, and therefore has not been detected. There is also the possibility that by restricting the space through which the product can fall, a circumstantial orientation will cause the product to touch both ends and get stuck in the restricted space, having been detected but not having been successfully sold. Others have provided sale detectors in which the impact on an output tray of a comparatively heavy item sold as a bottle or bottle is detected as a vibration. However, such detection is not economically feasible where at least some of the products sold are lightweight, for example in the case where a small number of large chips are presented in a seemingly large package but of very light weight manufactured from a synthetic plastic film. A particularly difficult situation arises when some of the products that are supplied are large so that a large cross-sectional area is required for the sales space, but other products are so small that an optical beam needs to be interrupted by the product and can be lost due to the circumstantial trajectory of the movement and the changing spatial orientation of the product that falls and that is sold. In this document certain terminology is used in an exemplary manner which is not intended to limit the applicability of the broader concepts of the invention. For example, the terms article, packaged product, product and the like are not intended to limit the concept of what items can be sold, or that are supplied in some other way. The use of the term "glass" is intended to mean that the front part of the vending machine can not be constituted, in whole or in part, of another material. Although processing costs may be lower, there may be more risk of a failed operation if a rotating spiral type vending machine is designed simply to have spiral or respective spirals rotating through a prescribed number of degrees or a prescribed amount of time before stopping turning, that is, without any sales detector. The user who observes the machine that stops operating but has not received the product, which can be remarkably close to being supplied, can oscillate the machine thinking that by providing sufficient physical drive to carry out the supply of the product, but It results in damage to the machine and possibly damage to the same person. Further, insofar as the cost of providing an "initial" switch for the motor termination operation after each respective scroll has rotated through an angular distance calculated as sufficient to supply the product, is added to the cost of The machine, and a sales control based on the extent of rotation limitation may not be less expensive than the sales detector.

A. BRIEF DESCRIPTION OF THE INVENTION Accordingly, an object of this invention is to provide an optical detection or sales detection system, which detects an object that has actually been sold. ^ / Another objective of this invention is to provide an optical sales detection system which detects the sold objects which are of various sizes and shapes. Another object of this invention is to provide an optical sales detection system which is robust against background noise and fuzzy signals and against conscious attempts to interrupt the detection system. Another objective of this invention is to provide a vending machine which has an optical sales detection system as indicated in the foregoing. Another object of this invention is to provide a method for detecting an object supplied with an optical detector which can detect supplied objects of various sizes and shapes. Another object of this invention is to provide a method for detecting an object supplied in a manner that is resistant against background noise, interference signals and conscious attempts to interrupt the operation of the system. To ensure that the machine of the vending machine will continue to operate until a product has descended through a sales space or until a set interval of time has elapsed, a continuous optical beam is placed through the sales space, through from which the product must fall. Preferably, the beam is thin for good sensitivity, but not so thin that it leads to alignment problems. A change in intensity in the beam is detected. In a first mode, infrared light is emitted by a row of emitters, diffused in a beam by a diffuser, and detected by a segmented detector arrangement, which includes two mirror surface collectors curved side by side. The collectors have a reflecting surface that is a section of a parabola that focuses the light collected on a photodiode placed substantially at the focal point of the parabolic surface. In a second embodiment of the invention, the collector has a bead-shaped component which has a first reflecting surface that is substantially planar. The flat reflecting surface of the collector in the second embodiment of the invention reflects the light entering the direction of the edge of the collector in the shape of a bead. The heel-shaped collector has an edge that is substantially parabolic and is a second reflecting surface. The light reflected from the parabolic edge of the heel-shaped collector is reflected to a photodiode or a concavity reflector constructed and placed substantially at the focal point of the parabolic edge of the heel-shaped collector. The surface of the concavity reflector is preferably substantially an inverted parabolic shape so that the incident light in the concavity reflector is redirected as a substantially collimated beam, directed substantially normally to the bead-shaped collector, substantially at the point of the parabolic edge of the heel-shaped reflector. An electromagnetic radiation detection element, such as a photodiode, is placed in the trajectory of the collimated beam formed by the concavity reflector. In a third embodiment of the invention, a substantially elliptical reflector has an interior reflective surface which is formed as an elliptical band. In the preferred embodiment, a single emitter is placed substantially at a first focal point of the elliptical reflector. More preferably, a concavity reflector is placed substantially at the first focal point of the elliptical reflector so that the light provided by the emitter in a direction orthogonal to the plane of the elliptical reflector is redirected towards the reflecting surface of the elliptical reflector, substantially at the plane of the elliptical reflector. An electromagnetic radiation detection element is placed in the second focal point of the elliptical reflector in the second embodiment of the invention. More preferably, a second concavity reflector is provided at the second focal point of the elliptical reflector and a photodiode is placed close to a concavity reflector so that the light reflected by the elliptical reflector and converging on the concavity reflector at the second focal point of the elliptical reflector is redirected substantially in a collimated beam orthogonal to the plane of the elliptical reflector. This provides a band of electromagnetic radiation, preferably infrared light, within the interior of the region defined by the elliptical reflector. An object that is to be detected, such as a sold article, passes through the beam of light that is provided within the interior region defined by the elliptical reflector. In each of the three currently preferred embodiments, the photodiode provides an output signal which is processed to determine whether an object has passed through the preferably infrared beam of light. In general, the electromagnetic radiation band can be provided in either continuous wave or pulse mode. In the preferred embodiments, electromagnetic radiation is infrared radiation by pulses.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred embodiment of the invention is described in more detail with reference to the accompanying drawings, in which: Figure 1 is a schematic vertical longitudinal sectional view of a vending machine with the front glass part that is provided with an optical sensor of sale, in accordance with the principles of the present invention; Figure 2 is a block diagram of the elements of the optical sale sensor of the present invention; Figure 3A is a front elevation view of a first collector body mode for the optical sensor sensors of the present invention; Figures 3B-3E are cross-sectional views of the collector body, taken respectively on lines 3B-3B, 3C-3C, 3D-3D and 3E-3E of Figure 3A; Figure 3F is a bottom plan view of the collector body of the first embodiment; Figure 4 illustrates a second mode of the collector in which a corresponding emitter is located; Figure 5A is a plan view of the second manifold embodiment; Figure 5B is a side view of the second collector mode; Figure 6 is an enlarged view of a section of a manifold shown in Figure 5A; Figure 7 is a perspective view of a combined emitter / collector structure according to a third embodiment of the invention; Figure 8 is a plan view in the plane of the elliptical reflector according to the third embodiment of the invention schematically illustrating the propagation of light in the system; Figure 9 is a schematic diagram of the electrical circuit of a previously preferred embodiment of the optical sensor sensing system of the present invention; Figure 10 is a schematic diagram of the electrical circuit of a currently preferred embodiment; Figure 11 is a schematic diagram of the electrical circuit of a circuit that provides an automatic and dynamic adjustment of the resistance of the pulses of light from the emitters; Figure 12 is a schematic diagram of the electrical circuit corresponding to Figure 10 which includes dampening the output through an emitter follower; Fig. 13 is a flow diagram illustrating the calibration of the service mode of the sales detector system; Fig. 14 is a flow diagram illustrating the calibration of the sales mode of the sales detector system; Figure 15 is a flow diagram illustrating the pre-sale calibration of the end detector system; and Figure 16 is a flowchart illustrating the sales operation logic circuit of the sales detection system.

DETAILED DESCRIPTION Schematically illustrated with the number 10 in Figure 1 is an exemplary vending machine in which the sales detection optical system of the invention can be provided and used. Much of the conventional structure has been omitted. In general, the vending machine 10 is shown with a cabinet 12 having opposite side walls, a rear wall, an upper wall and a lower wall which cooperatively define a forwardly facing cavity 14 arranged to have a plurality of tray mounts 16 mounted thereon in a plurality of vertically separated levels. In general, the vending machine has an electromechanical supply unit 16. In the example illustrated in Figure 1, the electromechanical supply unit 16a includes tray assemblies 16. Each tray assembly 16 has a plurality of horizontally and motorized spirals which are spaced apart from each other across the tray, and each of which extends longitudinally in a direction from the front to the rear deep, each spiral being it plugs into a drive mandrel of a respective drive motor which is positioned to unidirectionally rotate the coil about the longitudinal axis of the coil. In addition to the left and right vertical flanges 18 used to mount the tray assembly to the cabinet 12 preferably using physical drawer mounting elements which allow each tray assembly to be pulled outward like a drawer, and a rear flange for installation as an engine mount, the tray assembly includes a horizontal tray surface which is underlying all the spirals to provide support for the spirals that the packaged products are received in the upward opening packages respective formed between neighboring turns of the respective spirals. Some columns may have one spiral per column; others may have two coordinated spirals rotating one in the opposite direction of the other per column, with vertical side wall flanges mounted on the tray to divide the columns relative to each other. A separate front glass 22 is found, for example, approximately 23 cm (9 inches) in front of the leading edges of the tray assemblies as a door panel that can be opened / immobilized (not shown), through of which a possible user can observe the front packed products available for sale when the machine is operated. The door, towards one side of the glass front, further includes a selector panel, or generally a payment and selection unit (not shown) which includes a means to accept the user's payment, and for the user to select which column wants to receive from the front packed product. The sale, before the selection, is carried out by causing the respective motor assembly or the assemblies of the spiral or spirals of the respective column to rotate through a sufficient angular distance, so as to advance all the products housed in the rotations of the respective spiral or spirals forward so that the front part loses the support from the lower part as the upper part of the respective tray supporting surface advances and descends at the front end or ends of the respective spiral or spirals, and fall through the sales space 24 below the glass 22 forward to the bottom, into a sales hopper 26, from which it can be retrieved by the user, by temporarily pushing from the bottom a closed door 28 , resiliently driven, articulated at the top. (Typically, the door 28 is the outside of a double door arrangement configured so that as the user pushes the exterior door, a normally open interior door (not shown) on the top of the temporarily sold hopper correspondingly , to prevent the user from having access to the upper part of the sales machine cavity 14 by means of the sales hopper door 28. The present invention relates to an optical sales detection system, the detection subsystem of article which is placed transverse to the sales space 24 immediately above the sale hopper 26, at number 30, and a vending machine or dispenser having such sales detection optical system A first embodiment of the optical system 32 of sales detection is illustrated schematically and diagrammatically in Figure 2 in which, mounted behind an opening in a profiled wall 34 of the cabinet, by at least one, and preferably a row 36 of emitters of electromagnetic radiation, preferably positioned to emit infrared radiation through the sales space 24, towards at least one, and preferably a side by side pair of collectors 38 mounted behind an aperture on a wall 40 profiled from the cabinet. Preferably, the aforementioned opening is encristala with a diffuser panel 42 which can be of material and design conventionally used to diffuse light from fluorescent light tubes in office lighting fixtures. The opening can be implemented open or encristalada by a glass or plastic panel without transparent or translucent pattern. Preferably, the IR emitters 36 are provided in a plurality are arranged so that, in combination with the diffuser 42, they provide a thin plane of electromagnetic radiation which is generally horizontal (although a little inclined for laboratory considerations, as suggested by the inclined orientation of the subsystem 30, as shown in Figure 1) and thus is extensive and penetrating that even the smallest supplied package of article falling through the sales space 24 can not but momentarily decrease the radiation that reaches the manifolds 38 of the emitters 36 just before the package or article falls into the sales hopper 26. As one can see in figures 3A-3F, the manifolds 38 are preferably provided on a body 46 which is preferably molded of synthetic plastic material, and all of its matte black color on its front side, except for its two parabolic mirror-shaped surfaces 48 oriented horizontally and downwardly. These are placed immediately side by side as adjacent arches, to effectively cover, on the collection side, the entire front to back dimension of the radiation band that comes from the emitters 36 as it is affected by the diffusers. The number of arcs can be one, three or more, with two preferred for manufacturing considerations. A collector with an arc has advantages that one mirror is cheaper to make than two, and requires a less detector, and fewer circuits than in the case of two arcs. In addition, a simple mirror with a single detector has the advantage of greater sensitivity. With two or more detectors connected essentially in parallel, any signal from one is attenuated by the constant current flow through the others if they have not been similarly occluded. The signals are averaged over the number of detectors. In addition, a detector does not have the problems with lack of uniformity in sensitivity due to manufacturing tolerances of the detectors. The collector body 46 is placed for mounting the respective detectors, preferably photo-detectors 52 IR (FIG. 2) in the foci 54 of the respective collector mirrors 48 in one embodiment of the invention. The system of Figure 2 further includes other signal conditioning electronic circuits 58 operatively interposed between the detectors 52 and the vending machine control unit 62 of the vending machine 10, to which the 64 vending machine motors are operatively connected. (that is, to spin the spirals). The control unit of the vending machine has an instruction relationship with an IR light control relay and an energy transmitter array 66 which drives the IR emitters 36. Additionally, by providing a review of the sales detector system in use, the detector circuits capture the ambient light in both collectors 38 detected by both the detectors 52 within the emitters 36 turned off, and the microcontroller, i.e. the unit 62 of machine control stores the respective value. Then, the microcontroller turns on the transmitters 36, after which the system takes another reading from the detectors 52, and compares it with that of the previously stored reading from where the transmitters were inactivated. These two results are differentiated to obtain a reference value which equals the strength of the thin plane radiation beam detected according to the detectors, after correcting the ambient radiation at the same wavelengths that are not due to emissions by the transmitters 36, this reference value is determined when no products fall through the beam and the beam is otherwise not obstructed. By reference, the step of acquiring a reference value is practiced several times, until the result converges to a median which can be used as the reference value. The detection of a product falling through the beam 50 involves the detection of the radiation reaching the detectors as a result of the operation of emitters which has temporarily decreased by a preselected amount, which the machine control unit 62 registers. as a product fall, with the purpose of finishing the operation of the respective rotating propeller motor or motors. To the degree that there is a small dead space in the number 68 (Figure 3A) between the two mirrors, so that a small product falls with a circumstantial orientation which can slightly decrease the amount of radiation reaching the detectors, he prefers that in practice this modality of invention, the signals from photodiodes 52 are summed for comparison with a reference value. The optical components of a second embodiment of the invention are illustrated in FIG. 4 so as to schematically show the arrangement of the optical sales system in a vending machine. The sales detection optical system according to the second embodiment has a divergent element 70 and a manifold 72. The diverging element 70 and the manifold 72 are placed in the body 74 of the vending machine in a manner that provides a plane and a beam 76 which substantially subtends a region of the vending machine when a sold item passes during the sale. An LED bank can alternatively replace the divergent element 70, as in the first mode.

Similarly, the first embodiment may also use diverging elements that are substantially the same in structure as the collectors 38, rather than a bank of LEDs. Figure 5A shows a plan view of the manifold 72. Since the diverging element 70 is substantially the same in structure as the manifold 72, it is not shown in detail. Preferably, the manifold 72 is of a solid transparent material. Plexiglas or polycarbonate are suitable low cost materials. The manifold 72 has a first reflective surface 78 that is substantially planar. The reflective surface 78 can be provided by depositing metal on an outer surface of the manifold 72. A metal of aluminum, silver, gold or other metals conventionally known can be selected by providing reflective surfaces based on their specific application.

The manifold 72 has a second reflective surface 80 which is substantially parabolic in shape, as illustrated in the plane of Fig. 5A. Figure 5B shows a side view of the collector 72. The upper part of the collector 72 is painted black to protect the collector from foreign light. Similarly, the lower part 84 of the collector 72 is painted black, except in a transparent region 86, which allows the light from the flat part and the beam 76 to enter and reflect from the first reflective surface 78. Preferably, the detector 88 has an electromagnetic sensing element 90 positioned substantially at a focal point of the second reflective surface 80, and an electronic circuit board 92. The diverging element 70 (FIG. 4) provides a plane and a beam 76 by divergence of light from an emitter (not shown) such as an LED. The plane and beam 76 enter the manifold 72 through a transparent region 86 that is to be reflected from the first reflective surface 78 and reflected from the second reflective surface 80. The light reflected from the second reflecting surface is focused on the electromagnetic radiation detection element 90 which is preferably a photodiode (see Figure 6). Figure 7 illustrates the optical components of a third embodiment of the invention. The optical detection detection system, according to the third embodiment of the invention, has a reflective ring substantially elliptical. The reflective ring 94 constructed and arranged to encompass the sales ramp of a vending machine so that objects sold or otherwise supplied pass through an interior space defined by a reflecting ring. The interior surface of the reflective ring 94 is a reflective surface 96. An emitter 98 is positioned close to a first focal point for an elliptical reflecting ring 94 and an electromagnetic radiation detection element 100 is positioned proximate the focal point opposite the elliptical reflecting ring 94. The emitter 98 and the detector 100 are each supported by conventional mechanical supports which are not shown in Figure 7. Preferably, a first concave reflector 102 is placed substantially at a first focal point of the elliptical reflective ring 4, and is placed a second concavity reflector 104 at the opposite focal point of the reflecting ring 94. Concave reflectors 102 and 104 have substantially inverted parabolic surfaces. The substantially parabolic reflective surfaces of the second concave reflector 104 direct reflected light from the reflecting surface 96 into a substantially collimated beam that is substantially perpendicular to a plane of the elliptical reflecting ring 94. The emitter 98, in combination with the first concavity reflector 102, operates in a manner similar to the second concavity reflector and the electromagnetic radiation detecting element 100, but in a reverse light shift direction. In other words, a collimated beam of light emitted from the emitter 98 is reflected by a concave reflector 102 so as to be filled to substantially fill the inner region defined by the elliptical reflecting ring 94 with emitted electromagnetic radiation. In the preferred mode, the emitter 98 is a light emitting diode (LED). Figure 8 is a schematic illustration showing on a plane of the elliptical reflecting ring 94 which schematically illustrates the paths followed by some representative light rays. Light rays arising substantially from a first focal point 106 of the reflective ring 94 converge again substantially at a second focal point 108 of a reflective ring 94. The optical system according to the third embodiment of the invention provides an efficient means to detect light from the emitter 98 to substantially fill an interior region defined by a reflective ring 94, and then collect substantially all of the light emitted at the focal point. opposite of the reflective ring 94. For proper operation, it is necessary for the system to detect objects that have a narrower dimension equivalent to that of the narrowest article that is likely to be sold by the machine, for example 0.6 cm (0.25 inches), while objects fall at any speed which will be presented in a compulsory way in the vending machine. The sales detection system is preferably placed to reject false negative states, and to allow false positive states to the extent that the false positive states are entered by the operator. In the following discussion the terms emitter, collector and detector are sometimes used in the singular, without this meaning that any structure that is provided in the singular, the preferred numbers of these elements are as described above. In a first embodiment, the sales detection system works by detecting alterations of the steady state intensity of a flat band of electromagnetic radiation, preferably infrared light. In the currently preferred mode of the sales detection system, the emitter produces a pulse beam of electromagnetic radiation which is also preferably infrared light. In a pulse operation mode, the general concept is that detected pulses of light exceed a detection threshold when no object is located in the light beam, but they do not exceed the detection threshold for pulses emitted when an object is located inside. of the detection region therefore intercept at least a portion of the light beam. The detection threshold is generally selectable according to the detection sensitivity desired. In the preferred embodiment, the pulses of infrared radiation are emitted at substantially regular intervals, substantially with the same pulse width. The frequency of the pulses is chosen to be greater than the frequencies of the commonly encountered background sources, such as 60 Hz and 120 Hz, so as to allow filtering out of the low frequency background sources. Although pulses having substantially constant widths and substantially constant pulse intervals are currently preferred, the general concept of the invention includes encoded pulses emitted. A mode that uses encoded pulses will require greater complexity in the set of sales detection circuits, but will provide greater security against individuals who attempt to defraud the sales detection system. In the currently preferred modalities, the sales detection system consists of three subsystems: an emitter, a collector and a detector. A light band is pulsed by the emitter through a gap and focused on a photoelectric transducer within the collector in the preferred embodiment. As indicated above, the invention is not limited to operating only one pulsed mode. The general concept of the invention includes a "continuous wave" emitter to provide a substantially constant beam of electromagnetic radiation but which is currently not the mode more preferred. Objects placed in this separation partially or completely interrupt the light beam and thus vary the output of the collector. The detector includes a circuit which translates the collector output signal into a true or false detection signal. The protocol used in the preferred embodiment states that each pulse supplied by the emitter must be detected where there is no object in the detection region. The broader concept of the invention includes allowing a certain number of pulses not detected when there is no object in the detection region. In the preferred mode, the pulse frequency is selected to be sufficiently large so that a plurality of pulses are emitted during the movement of an object through the detection region. If the number n of consecutive output pulses is below the detection threshold, then detection of a supplied object is marked. Pressing the light from the emitters has two effects: first, higher instantaneous beam intensities can be produced without high current consumption, and secondly, the signal-to-noise ratios are increased by showing only the modulation frequency. Line noise and bulb oscillations are well below this frequency, and are attenuated. Diffuse light entering the collector from a multitude of sources can cause a false activation of the detector. In addition, if it is sufficiently intense, the collector signal can exceed the dynamic range of the circuits and allow the products to fall without detection. In addition, if the light intensity source is modulated, the collector output will have a strong component that reflects the carrier frequency, which can interfere with accurate detection. False signals can also be generated, whether the intensity of the excitation beams, as they are perceived by the collector, change due to reasons other than the existence of an object interrupting the diffuse light. A major contributor to this effect would be the mechanical vibration of the system, which may cause the transducer to shift its position relative to the point at which the excitation beam is focused. There is a general inverse relationship between this "microphonic noise" and the rejection of diffuse light: the narrower the focus, the greater the rejection of the diffuse light, the lower the reflection of the focus that is required from the transducer. produce a false signal. However, such low frequency microphonic noise can be eliminated by filtering in pulse mode by selecting a pulse frequency that is greater than the microphone noise frequencies, dynamically adjusting the detection threshold or adjusting the detection criterion. (that is, by selecting the number n). The criteria established in the above and the considerations are solved through the design of each of the collectors, the emitter and the detector. The field of view of the collector must be wide enough to detect all falling objects. Preferably, substantially all of the light in the plane of light is collected and concentrated on a focus by the collector. The field of view of the collector is preferably limited only to the region of the light plane so that it does not allow significant amounts of external light to be collected along the plane of light. In a first preferred embodiment, this is obtained by constructing the collector so as to have an electromagnetic radiation detection element placed in the focus of a reflector. A photodiode is used as the electromagnetic radiation detection element in the preferred embodiment. The reflector is a sector of a ring section of a parabolic reflector. The center of the section is a point orthogonal to the parabolic axis and in the same coordinates along the axis, as the focus. This arrangement produces a flat, slightly curved field of view which is orthogonal to the parabolic axis. Two such collectors and detectors are used, side by side, to adapt to the space restrictions of the vending machine. There is a barrier that seals the space encompassed by mirrors and transducers. By design, the parabolic mirrors of the collector reject rays of light that are not parallel to the axis of the mirrors. However, neither the coating of the mirror nor the uniform condition and shape of the surface of the reflectors are perfect, so that they will scatter a certain amount of diffuse light. Similar problems arise when it is disseminatedReflects or refracts diffuse light in a path parallel to the excitation beam by other surfaces besides the mirrors. To absorb the diffuse light reflected for the most part, all surfaces except the mirrors of the optical cavity of the collectors are painted flat black or made of a dark matte plastic material. The errors of the light reflected by the mirrors are solved by the detector circuit. In addition, the selectivity of the excitation beam is carried out by the use of infrared emitters and receivers which are spectrally coupled. UV and visible light, as well as most of the IR wavelengths in this way are significantly attenuated.

The mechanical connection between each mirror and each electromagnetic radiation detection element is very rigid, as it should be, since due to the parabolic shape of each mirror, even a small deflection can result in a large change in the output. The emitter must feed an excitation beam to the collector that is in a brightness, parallel to the parabolic axis of the collector, and of a reasonably uniform intensity throughout the entire field. But afterwards, it should not be so directional that small deflections in its inclination with rct to the collector result in large deviations of radiant intensity on the surfaces of the transducers. A modified parabolic reflector, for example, one that substantially coincides with the corrnding collector mirror, produces a beam with a certain amount of sphericity and can be used, but it is more economical to use a linear array of separate LED emitters behind a lenticular array thin of concave meniscus lenses. Other light sources can also be used, such as laser diodes, gas discharge lamps or incandescent radiation sources. LEDs with interconstructed parabolic reflectors which provide beam direction and lenticular array refract the beam components and give a light sphericity to the radiating field, enough so that the spatial reflections of the emitter / collector pair do not result in large oscillations in the signal. The LEDs are driven at high currents, with little work cycle, and at a selected frequency, none of whose exact values is cially significant for the design. There is a union inferior to the modulation frequency indicated by the minimum size and the maximum speed of the detectable objects, but generally, the higher the frequency the better; The limiting factor is the cost of the component. In the presently preferred implementation, the pulse current is 1 amp in a duty cycle of 2% at 2 kHz. The core of sets of detector circuits is a non-linear element (or a linear element whose gain is such that its transfer function approaches non-linearity), whose threshold is programmable and activated by the output of the collector transducers. Most of the circuitry used in the detector is required to follow the system parameters, and to set the activation threshold. The following circuit description refers to the previously preferred embodiment illustrated in Figure 9. The cathodes of the photodiodes contained in the collector body are joined to the photodiode inputs, and their anodes are connected to ground. A pulse of transducer light appears through the photodiodes as a sudden slope edge, with a logarithmic decay support at the point of polarization establishment. This is due to the action of the automatic polarization circuit described in the following. Q7, D14, D15, U25C and their associated feedback components form a network and closed loop bias filter, R80 and Cll are a low pass filter which does not allow edges of the cutting photodiode signal to pass through U25. However, the limiting frequency is high enough to pass slower signals (such as incandescent flashes). The signals that constitute the non-inverting input of U25 are amplified, and modulate Q7 which controls the reverse current through the photodiodes. The steady state is reached when the integrated output of the photodiodes is approximately equal to the polarization voltage set by the divider R109-R110. This feedback mechanism regulates the polarization point of the photodiodes by tracking the changes in light intensity which are slower than the modulation frequency. Since sudden transitions are never made at the base of Ql, this does not clear the real pulses when correcting your excursions, so that the charge in the photodiodes results from a pulse of cutting light that is emitted more slowly through R80. This causes the decay edges whose sum is coupled by AC through C9 and CIO to the input of a nearly non-linear switch, in this case U25A. Several types of operational amplifiers that include LM324 will activate an internal parasitic transistor and will switch its high output either if its inputs decrease below the negative supply by a certain threshold. This is a non-destructive condition in LM324, with the condition that the input current is limited. Thus, a positive advancing pulse now appears at the output of U25A, which persists to the extent that a negative output signal with peaks is below the threshold U25A. There is only the matter of setting the threshold at the precise point where a drop in signal strength due to a deviation from a stable state (such as that caused by an interrupting object, for example) will momentarily maintain the negative signal peak of the fall below the threshold and activate the switch U25A. This is carried out by feedback circuits formed by U25A, B, C and D. (There is nothing limiting in the design when choosing the U25A configuration.) It could also have been configured as a comparator with power-advancement compensation or could For example, if the switch in place is truly non-linear, layers of only two states of equilibrium, all that will be required will be to establish a DIO point, and the circuit will still work the same way.The only salient points of this part of the design are that the switch acts fast and is a feedback element in its threshold bias circuit). Suppose that there are no input pulses below the threshold. The dividers R117-R118 and R115 ensure that the output of U25A will be connected to ground. If there is a charge in C8, it is finally purged. Also suppose that the negative input of U25D is somewhere around Vcc / 2, which allows a linear operation. The output of U25D must then decrease to ground, by inactivating R114 with it. As a result, the DC polarization on the right side of the AC coupling capacitors C9 and CIO must be at zero, so that any pulse is transmitted through them, under the conditions that it has a certain minimum amplitude, transcending the threshold of U25A and causing it to disconnect. These pulses accumulate in a DC voltage in the peak detector formed by R121, C8 and the splitter R122-R123, which is fed back through U25D, and increasing its output and polarizing the coupling capacitors C9 and CIO away from the voltage threshold.

Finally a steady state is reached, in which the capacitors are only polarized enough so that U25A generates pulses of only the correct height for the peak detector to keep the system balanced. If all the input pulses of a sudden start decrease in magnitude by a certain amount, they will be below the threshold and will not appear at the output of U25A. (If U25A has been a non-linear switch, and the peak detector is replaced by an integrator, it would be in a positive-forward duty cycle of the switch's output pulses which will take the place of the pulse amplitude as the important parameter of the system ). The magnitude of this quantum, which is the difference between the amplitude of a pulse below the threshold and one that is not, is that the selectivity (the minimum signal deviation which is detectable) of the system is established. This is why the switch should behave almost non-linear. If not, the quantum would be large, with a greater analog interval within it. The system would become a simple integrator without a clear distinction between the pulses which are present and those which are not. The selectivity parameter is controlled by the divisor R117-R118. The time constant set by C8 and its discharge paths is long enough so that its accumulated charge appears as a constant bias voltage to the bias amplifier U25D. However, it begins to discharge immediately after each pulse peak that is applied through R121. A large object that occludes the excitation beam will cause the input pulses to the switch back far away from the threshold. It will take a relatively long time for C8 to discharge enough to polarize C9 and CIO below the threshold and reassume output pulse output; therefore, large objects are easily differentiated even if they require many seconds to traverse the beam. Small objects do not produce much of a recoil, so U25A will always be close to the critical condition, while objects pass through the beam. Consequently, it does not require much of a bias correction at C8 to break the threshold. Small objects must ensure that they can perform the pulses that are removed from the threshold faster than C8 repolarizing them towards the threshold. This sets a limit on the lowest allowable transit time for very small objects. The system can be adjusted to greater sensitivity when reducing R117, but the cost would be greater susceptibility to microphonic noise. Since U25A is not truly linear (in fact, some linearity is required for the peak detector to be stable) there is a narrow linear range in which subnormal peaks can occur at its output. These are treated as microphonic noise and are rejected by the comparator U8B which also squares and inverts the output pulses, making them ideal for microcomputer interruption generators. Previously it has been assumed in this description that the investment input to U25D is almost Vcc / 2. Actually, the absolute number is not important insofar as it polarizes U25D in the linear region. This output follows the total lighting level of the photodiodes. As the illumination increases, the output of U25C decreases, as with U25B, which causes U25D to increase its output and allows R114 to polarize C9 and CIO back out of the cut. Q8 is a follower which unloads the U25A output. It follows the total energy that reaches the surface of the photodiodes and is used by the microprocessor to compare this value with the value stored in the memory before initialization. If this number is decreased by a certain percentage, any of the collectors is damaged or there is too much dust accumulated in the system, the program will then signal an error condition and take the line out of the machine.

If there is much more light than expected, it means that someone is intentionally trying to overload the system and the program will cancel the sale. The differences of the currently preferred mode of the detector circuits of the above preferred embodiment that has been described above with reference to Figure 9, are described below with reference to Figure 10. The embodiment illustrated in Figure 10 is currently preferred in relationship to the modality illustrated in Figure 9, because the part count is lower, the greater insensitivity to the variation of the component, an increased stability of operation, a faster adjustment to a state at rest and an acceptance of a frequency carrier from 2 kHz to 15 kHz. In comparison with the circuit of Figure 9, in the circuit of Figure 10, the automatic polarization circuit (U1B) remains basically the same. DI and D2 have been added to polarize the feedback loop containing Ql in the linear mode by a larger range of illumination. R2 is reduced for the same reason. C3 is increased to buffer overvoltages that could be incorporated into an average illumination signal by U1B and provide an erroneous reading.

The main difference is in the activating circuit UlC (U25A) in the original circuit. While in the figure 9 the activation function is based on a collateral effect LM324 for operation, the activation of figure 10 is a conventional comparator with positive feedback. The static threshold for activation is established by the divisor R16-R18. The negative feed peaks fed by C4 and C5 appear inverted and highly amplified at the UlC output if their tips are below the threshold. The output of the peak detectors (D5-C6) is fed back to set to C4 and C5 to ensure the output pulses continue to appear. A momentary suppression of the photodetector signal will cause the pulses to be lost while the peak detector adjusts the clamping level, providing the detection signal. Since the activation input (pin 9, UlC) has no longer been driven below the negative supply, the circuit voltage levels are now such that the polarization amplification U25D of FIG. 9 is provided biased directly from the peak detector. through R12. Additionally, the input impedance observed in leg 9 is now greater, and smaller coupling capacitors C4 and C5 are needed. The lack of activation linearity is provided by positive feedback through R15.

C7 reinforces the sensitivity of the activators for fast and short changing stimuli (falling objects, small and heavy). The hysteresis inherent in the positive feedback of this activating circuit will suppress an output pulse in leg 8, UlC, even as the peak detector is corrected for a momentary imbalance due to a missed pulse. This small phase polarization allows the use of a peak detector with a much faster decay than that of the circuit of FIG. 9, and therefore a much faster rest settling time. As in Figure 9, the output pulse is inverted by the comparator U1D. The crossing point of the output pulse is controlled explicitly by the divider R19-R21, instead of placing confidence in the variations of the downstream logic circuit. Since the pulse is switched on the maximum sudden change rate at the input of U1D, R120 of FIG. 9 is not required in the circuit of FIG. 10. The conditions of system failure are indicated by an analog voltage on the leg. of lighting. In the version of Figure 9, that output is buffered by Q8 and generated by the peak detector. This signal level indirectly contains the average illumination through the path U25C U25B U25D R114 (polarization in) U25A.

In the version of figure 10, the illumination signal again is a composite of the peak detector output and the degree of illumination of the photodetector, except that in figure 10, these two components are added directly (have opposite directions to the stimulus). identical) in U1A. The amount of illumination is the integrated error signal generated by the photodetector polarization U1B amp, isolated by R6 and accumulated in Cl. R8 provides a path of from to download Cl. The contribution of the peak detector is added through R14. and, when it is static, it indicates to the controller that the system is balanced and ready to be in detection. R9 protects U1A from the effects of the shielded cable capacitance. If this compound signal does not reach a static value that is within a pre-established interval, at a certain time allowed, the sale will not begin. UlC is a sensitive activator, and must necessarily operate on the edge of instability; therefore, this detector circuit (as in the case version of figure 9), should be mounted close to the photodiodes for proper operation. If the capacitance of the cable between the photodiodes and the circuit is too large, poles will be generated for both U1B and UlC which are within the modulation frequency. The compensation on U1B can degrade the rejection of noise from the system, and the compensation on UlC can force the activator to be out of non-linearity, interrupting its function. Therefore, the least expensive solution is one in which the capacitance of the photodiode is minimized. In the course of testing the invention using the preferred detection circuit, the inventors discovered that all of the variations of the component (mechanical, optical and electrical) conspire to reduce the perceived output of the emitters and cause the detector circuit to attempt operate outside of your design parameters. This led to disadvantages with respect to the uniformity of operation which was not assured from one system to another, and the manufacturing capacity of line assembly was difficult or possibly prevented. A solution to such problems is found by providing an automatic and dynamic adjustment of the force of the pulses of light from the emitters to compensate for these variables and provide uniformity in the system. The circuit illustrated in Figure 11 accomplishes these objectives in an economical manner. The circuit illustrated in FIG. 11 comprises an adjustable current source modulated in pulse width (PWM) in series with an interrupting transistor. The feedback for PWM is provided by the lighting that exists. The inventors also discovered, during the tests of the invention, that the output damper UlD is sensitive to the capacitive load of its output when its output line runs through the shielded cable and is distorted by the "slack" signal. The circuit provided in the diagram of Figure 12 is the same as that in Figure 10, except that the output through the emitter follower is damped. This is only one of many possible distributions for the capacitive charging problem, and does not limit the general concepts of the invention. In the preferred implementation of the equipment for sale with the preferred embodiment of the sales detector of the present invention, after a spiral or a pair of spirals that begin to rotate after the selection of a product to be sold, the spiral or spirals do not cause them to stop simply because they have rotated through a regular distance calculated as sufficient to have caused the corresponding product column to have been transported far enough forward so that the product that is further forward only until the product that is forward has lost support from the 8fá > _ lower and, as a result, has fallen from the respective shelf into the sales space. Instead, the spiral or spirals rotate until it has been detected by the sales detection system that the product has been sold or (in the preferred implementation) that the spiral a, or that the spirals have rotated approximately 540 ° and then they are pressed three times (so, if it is not detected that has been supplied), the customer is provided with a selector panel to choose to have a form of payment refunded or select a product from another column. Therefore, the vending commutator will sell properly even if a bag between the turns of a spiral or a pair of spirals has been left by empty error when the machine has been recharged, or if a product is poorly oriented towards the front, or subsequently reached the point at which it will lose support of the underlying tray surface in comparison with other products packed behind in the packages between the rear turns of the spiral or respective spirals. By using the LEDs spaced closely behind a lenticular diffuser in the first or second embodiment, the intensity of the beam is caused to be substantially constant in a depth direction from the front to the back of the sales space. The emitter array and the concavity reflector in the third embodiment provide a substantially uniform plane of illumination light. The plane of the beam of light should be placed below the position of the lowest tray, but above the wrapping of the movement of any structure of the doors of the sales hopper (for example, on the inner door that bends upwards) . In a preferred embodiment of the invention, the sales detection optical system performs calibration operations. More preferably, the sales detection system has a plurality of calibration operations, each of which is performed depending on the operating conditions of the vending machine. Figures 13, 14, 15, and 16 are flow diagrams illustrating the calibration and logical processes of operation of an implementation of an embodiment of the invention. The calibration of the service mode illustrated in Figure 13 is carried out only when specifically selected. The sales mode calibration illustrated in Figure 14 is carried out every minute while the vending machine door is opened, and every minute for ten minutes after the vending machine door closes. Calibration in the sales mode is then carried out at 3-minute intervals or other intervals during normal operation. The pre-sale calibration is carried out immediately before a sale and is only used to check to see if the stock detector is functioning properly. Calibration values are not changed during calibration - before the sale. Figure 16 illustrates the operation of the sale. In a particular embodiment, the pulse width ("PULSE") is twice the pulse of the measured detected signal and varies from about 16 μsec to about 50 μsec. The ("BASE") for the light intensity is a composite signal which combines ambient and excitation light. The ambient light is external to the system and the excitation light is from the system. In a particular implementation of the preferred embodiment of the invention, the bases vary from 0 to 200. The programming element (software) will indicate an error if the value is less than 10 or greater than 180. A larger number indicates a lower intensity of light. The pulse width modulation (PWM) of the LED drive signal varies from 300 to 800 in the implementation of the preferred embodiment of the invention. A higher number of PWM indicates a lower intensity. The PWM is the intensity of the LED activation signal needed to generate a received pulse that is in PULSE units of width. The following describes the currently preferred calibrations: Complete Calibration A full calibration always starts calibrating at the lower limit of the predefined PULSE width, which is currently preferred to be eight (8). Calibration in this mode will only be completed only when the following conditions are met: - approximately one hundred sixty (160) consecutive pulses of the detector system are received with a PULSE width variance of less than about 1 microsecond. - PULSE must be less than approximately fifty (50). - BASE must be between ten (10) and one hundred and eighty (180). - PWM must be between three hundred (300) and eight hundred (800).

A complete calibration resets all saved system variables and then re-calibrates the systems to meet the requirements as defined above. The PULSE is initialized at its lowest point and then increased by a preselected amount (which will be referred to as a "quantum") to find a stable value to ensure that the optimal PULSE width is obtained for the current external variables.

External variables include temperature, ambient light and dew (in the mirrors). Note that the calibration requirements for the PULSE width variance are extremely restricted. This is done to ensure that the system is stable. If this variance requirement is satisfied then the system is ready and able to make sales.

Calibration without Limit A calibration without limit will start the calibration at a predefined value provided to PULSE minus one (1) as PULSE. This value is defined as the last calibration performed within the specifications defined in the given calibration type. The PULSE value is subtracted by one (1) to allow the system to initialize a more sensitive level under normal operating conditions. Calibration in this mode will be completed when the following conditions are met: - approximately one hundred sixty (160) consecutive pulses of the detector system are received with a PULSE width variance of less than about two (2) microseconds. - PULSE must be less than about fifty - BASE must be between ten (10) and one hundred and eighty (180). PWM must be between three hundred (300) and eight hundred (800).

An unlimited calibration does not reset any of the system variables, but rather initiates a predefined point minus one (1). At this point the system will initialize or increase the PULSE width to meet the defined requirements for an unlimited calibration. Note that the value of BASE and PWM can change (as long as they are within the valid range defined above) as much as needed, without any limit. No limits are used with this calibration to ensure calibration is completed. This type of calibration must be completed when the external variables of the system are changing rapidly. Unlimited calibration will ensure that the system still works.

Limited Calibration A limited calibration will start by calibrating at a predefined value provided to PULSE minus one (1). This value is defined as the last calibration performed within the specifications defined in the given calibration type. The PULSE value is subtracted by one (1) to allow the system to initialize a more sensitive level under normal operating conditions. Calibration in this mode will be completed when the following conditions are met: - approximately one hundred sixty (160) consecutive pulses of the detector system are received with a PULSE width variance of less than about two (2) microseconds. - PULSE must be less than about fifty (fifty) . - BASE must be between ten (10) and one hundred and eighty (180). PWM must be between three hundred (300) and eight hundred (800).

The total changes in the PWM and the BASE can not be greater than approximately +/- 10%. Limited calibration is similar to calibration without limit, except that the limited calibration will limit the difference between PWM and the BASE to approximately +/- 10% of the previous calibration. This is done to avoid any misuse of the system. The assumption is made that if these difference changes are greater than about +/- 10% since the last calibration, then something is wrong with the system because under no circumstances do these system variables (PWM and BASE) change so much. quickly.

Calibration Verification The sole purpose of calibration verification is to verify the functionality of the fall system directly before a sale. Calibration in this mode will use pre-existing values for PULSE and PWM to test the system. No variables will be changed in a calibration check. For a sale to begin, the following conditions must be met: - Approximately sixty-four (64) consecutive pulses of the detector system with PULSE width variance of less than about three (3) microseconds are received. - BASE must be between ten (10) and one hundred and eighty (180). - The total difference between PWM and BASE can not change by more than +/- 10%.

Since the calibration constants are not allowed to change, less stringent requirements are imposed in this mode. A calibration check is done only before a sale. It is done to ensure that _.t-fa «aa a ... the system is still working directly before the sale. If the system is not worked, then the product will not be sold.

Activation Each time the controller is activated, the controller checks to see if a calibration should be performed. If the controller has been inactivated for more than approximately 5 minutes or if the current ambient temperature has changed by approximately (two (2) or more degrees Fahrenheit (approximately one (1) or more degrees Celsius)) (in any direction), then a calibration is performed without limit. The assumption is made that if either of these two conditions is satisfied, then there is no likelihood of misuse. An unlimited calibration is performed to make sure that the system is working. If the time since the last calibration (including time without power) is between approximately three (3) and approximately five (5) minutes, then a limited calibration is performed. The possibility of misuse is very likely for this situation and therefore the difference between PWM and BASE is limited to +/- 10% change. A calibration is performed immediately to simulate conditions __. normal operation, when a calibration occurs in approximately every three (3) minutes. If the last inactivation occurred approximately in the following three (3) minutes, then no calibration occurs. The probabilities of misuse are high, so it is important to perform a calibration with limits (see limited calibration) only in the indicated time.

Service Mode (Option 5) If option 5 is selected in the service mode, then a full calibration is performed. Since the calibration in the service mode is deliberate, then this calibration will reset all the variables of the detector system and then it will be initialized. The sales mode with the door open or the sales mode with the door closed is less than 10 minutes. For these two conditions, an unlimited calibration occurs every minute. Variables such as temperature or dew in the detector's mirrors are likely to change rapidly under these circumstances. Calibration will often allow the detector system to function properly. When this calibration occurs, if the new value for BASE is lower than the previous value, then a new calibration without limit will be made directly after the first calibration (without waiting one (1) minute). This will continue to happen until the stored PULSE width is no less than the previous one or until PULSE reaches the lower limit of eight (8). This is done to ensure that the state of the most sensitive system has been reached.

Sales Mode with the Door Closed more than Ten Minutes If the door has been closed for more than ten (10) minutes, then a limited calibration occurs approximately every three (3) minutes.

Presale Before the sale, a calibration check is performed to ensure that the fall detector system works properly before the sale. Table I provides a list and description of the detector error codes specified in Figures 13-16.

TABLE I ERROR TYPE NUMBER POSSIBLE REASONS ERROR The signal is low Detector defective, quality Optical path partially blocked, EM interference in the detector Displacement Inadequate calibration, drastic environmental Excessive and sudden change in temperature or ambient light, Sudden degradation in detector efficiency or from the transmitter board Deadly failure of the defective detector or detector blocked (this can also occur if there is extreme condensation on the detector's mirrors), connector cable disconnected In addition to indicating a type of calibration error, the memory is stored in the memory and the time along with the type of error in the preferred mode. Now it will be evident that the optical system of sales detection for control of a vending machine as described in the above has each of the attributes that are established in the specification under the heading "brief description of the invention" mentioned above. Because it can be modified to some degree without departing from the principles of the same as indicated and explained in this specification, it should be understood that the present invention embraces all such modifications and that they are within the scope of the following claims. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention

Claims (57)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. An optical system for detecting sales for control of a vending machine which has at least one mechanism placed to start the operation before the selection by a user for sale of an article in a sales space through which the item falls into a hopper accessible to the user, the sales space has a defined lateral width and a defined depth from the front to the rear, the detector system is characterized in that it comprises: at least one emitter of electromagnetic radiation and an associated structure, placed at a lateral end of the sales space for emitting electromagnetic radiation in a broad plane which substantially completely covers the cross section of the sales space below at least one mechanism, but above the item, which upon being sold , it is placed leaning on the hopper accessible to the user; at least one electromagnetic radiation detector; a collector body that includes at least one collector positioned at an opposite side end of the sales space to collect the electromagnetic radiation that reaches at least one collector in the plane, substantially completely complete the sales space, and to return to direct such electromagnetic radiation collected to at least one electromagnetic radiation detector; a machine control unit arranged to complete the operation of at least one respective mechanism to initiate the operation; and set of control circuits that operatively connect at least one detector to the machine control unit, and positioned to provide a signal to cause the machine control unit to complete a sales cycle of at least one respective mechanism on at least one detector which detects that the electromagnetic radiation reaching at least one collector as a result of the emission of electromagnetic radiation by at least one emitter, has temporarily decreased by a predetermined amount.

2. The optical detection system for sale, according to claim 1, characterized in that: at least one emitter of electromagnetic radiation is placed to emit electromagnetic radiation predominantly in the infrared part of the electromagnetic radiation spectrum.

3. The optical detection system of sale, according to claim 2, characterized in that: the associated structure comprises a diffuser placed near the front of at least one emitter in relation to the collector body, to diffuse electromagnetic radiation emitted by at least an emitter in the plane.

4. The optical detection system of sale, according to claim 3, characterized in that: at least one emitter comprises a plurality of emitters operated in coordination, arranged in at least one row which extends from the front to the rear, deep in the sales space.

5. The optical detection system for sale, according to claim 1, characterized in that: at least one emitter comprises a plurality of emitters operated in a coordinated manner, arranged in at least one row which extends from the front to the back, deep in the sales space.

6. The optical detection detection system, according to claim 5, characterized in that: each emitter is a light emitting diode.

7. The optical detection system for sale, according to claim 1, characterized in that: at least one electromagnetic radiation detector is placed to receive the collected electromagnetic radiation, which is collected by at least one collector, from a direction which it is substantially perpendicular to the plane.

8. The optical detection system for sale, according to claim 7, characterized in that: at least one electromagnetic radiation detector is placed under the at least one collector.

9. The optical detection system for sale, according to claim 7, characterized in that: at least one collector comprises at least one parabolic mirror surface that is provided on the collector body.

10. The optical detection system for sale, according to claim 9, characterized in that: at least one detector comprises, for each parabolic mirror surface, a photodetector placed in an optical center of the respective parabolic mirror surface.

11. The optical detection system for sale, according to claim 10, characterized in that: each photodetector is mounted on the collector body.

12. The optical detection system for sale, according to claim 9, characterized in that: at least one collector comprises at least two collectors placed side by side deep within the sales space.

13. The optical detection system for sale, according to claim 12, characterized in that: at least one electromagnetic radiation detector is placed below the at least one collector.

14. The optical detection system of sale, according to claim 4, characterized in that: At least one electromagnetic radiation detector is placed to receive collected electromagnetic radiation, which is collected by at least one collector, from a direction which is substantially perpendicular to the plane. ^^^^^? bjíio ^^ T ^^^^^^^^ j ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^.

The optical detection system for sale, according to claim 14, characterized in that: at least one electromagnetic radiation detector is placed below the at least one collector.

16. The optical detection system for sale, according to claim 14, characterized in that: at least one collector comprises at least one parabolic mirror surface provided on the collector body.

17. The optical detection system for sale, according to claim 16, characterized in that: at least one detector comprises, for each parabolic mirror surface, a photodetector placed in an optical center of the respective parabolic mirror surface.

18. The optical detection system for sale, according to claim 17, characterized in that: each photodetector is mounted on the collector body.

19. The optical detection system for sale, according to claim 16, characterized in that: . At least one collector comprises at least two collectors arranged side by side deep in the sales space.

20. The optical detection system for sale, according to claim 19, characterized in that: at least one electromagnetic radiation detector is placed below the at least one collector.

21. The optical detection system for sale, according to claim 20, characterized in that: each emitter is a light emitting diode.

22. The optical detection detection system, according to claim 1, characterized in that: the control circuitry includes an adjuster for adjusting the predetermined amount.

23. The optical detection system for sale, according to claim 1, characterized in that: the control circuits and the control unit of the machine are placed to reduce the effect on the sensors of a temporary decrease of the electromagnetic radiation reaching the collector due to ambient electromagnetic radiation which is not emitted by at least one emitter.

24. The optical detection system for sale, according to claim 1, characterized in that at least one mechanism for indicating the operation on the selection by a user for the sale of an article is an electric motor driven mechanism.

25. An optical detector for a vending machine, characterized in that it comprises: an elliptical reflector ring having an interior reflecting surface; an emitter of electromagnetic radiation placed close to a first focal point of the elliptical reflector ring; a detector placed next to the second focal point of the elliptical reflector ring, the detector has an electromagnetic radiation detection element, wherein the electromagnetic radiation from the emitter is reflected by the reflecting surface of the elliptical reflector ring and is focused substantially on the element of detection of electromagnetic radiation, and the emitter and the detector reserve a space between them to allow the subjects to be detected when they pass through it.

26. The optical detector according to claim 25, characterized in that it further comprises: a first concave reflector placed substantially at the first focal point of the elliptical reflector ring; and a second concavity reflector placed substantially at the second focal point of the elliptical reflector ring, wherein the first concavity reflector redirects the electromagnetic radiation from the emitter to improve the intensity of the electromagnetic radiation from the emitter to the space reserved between the emitter and the detector, and the second concavity reflector redirects the electromagnetic radiation incident thereto on the electromagnetic radiation detection element.

27. A vending machine, characterized in that it comprises: an electromechanical supply unit having a plurality of product containment regions; a hopper accessible by the user below the containment regions adapted to receive products supplied from the product containment regions; a payment and selection unit that is in communication with the electromechanical supply unit, where the payment and selection unit sends a signal to the electromechanical supply unit to supply a selected product after the consumer has selected and satisfied the payment for the selected product; and an optical detection detection system located next to the electromechanical supply unit, the optical detection detection system is in communication with the payment and selection unit and the electromechanical supply unit, where the sales detection system comprises : an emitter placed at one end of the hopper accessible to the user that provides electromagnetic radiation substantially subtracting a detection region through which an object to be detected will pass through, a collector placed in a path of electromagnetic radiation and which Substantially subtends the detection region, and a detector placed near the collector, the detector receives electromagnetic radiation substantially not attenuated from the collector, when the object to be detected is outside the detection region, and receives attenuated electromagnetic radiation from the collector when the object to be detected is in the detection region.

28. The vending machine, according to claim 27, characterized in that the collector comprises an elliptical reflector ring having an interior reflective surface, the emitter is placed next to a first focal point of the reflector ring, the detector has a radiation detection element The electromagnetic radiation placed near the second focal point of the reflector ring, the electromagnetic radiation of the emitter is reflected by the reflecting surface of the elliptical reflecting ring and focuses substantially on the element -detection of electromagnetic radiation, and the emitter and the detector reserve a space between the same to allow objects to be detected so that they pass through them.

29. The vending machine according to claim 28, characterized in that the sale detection system comprises: a first concavity reflector placed substantially at the first focal point of the elliptical reflector ring; and a second concavity reflector placed substantially at the second focal point of the elliptical reflector ring, wherein the first concavity reflector redirects the electromagnetic radiation of the emitter to improve an intensity of. electromagnetic radiation of the emitter in the space reserved between the emitter and the detector, and the second concavity reflector redirects the electromagnetic radiation incident therein on the electromagnetic radiation detection element.

30. The vending machine, according to claim 27, characterized in that the collector has a reflective surface that is a section of a parabolic surface, the reflecting surface of the collector reflects at least a portion of the electromagnetic radiation substantially subtending the detection region. to the detector.

31. The vending machine, according to claim 30, characterized in that the collector has a flat reflecting surface which is substantially a flat reflecting surface, the flat reflective surface is inclined at an angle with respect to the electromagnetic radiation incident from the electromagnetic radiation which subtends substantially the detection region to reflect incident radiation to the parabolic surface. _,

32. The vending machine, according to claim 27, characterized in that the emitter provides electromagnetic radiation by pulses.

33. The vending machine, according to claim 27, characterized in that the emitter provides continuous electromagnetic radiation.

34. The vending machine, according to claim 27, characterized in that the emitter provides infrared radiation.

35. The vending machine, according to claim 27, characterized in that the optical detection detection system has at least one automatic calibration operation mode.

36. A method for detecting an object supplied by a vending machine, characterized in that it comprises: emitting electromagnetic radiation in a beam so that the electromagnetic radiation substantially subtends a detection region through which the supplied object will pass before reaching an accessible hopper for the user; • ^ collecting the electromagnetic radiation from the emitter and directing the collected electromagnetic radiation to a detector element of electromagnetic radiation; selecting a detection threshold that is exceeded by the object to be detected does not intercept the destruction region and is not achieved when the object intercepts that region; and compares a plurality of signals from the electromagnetic radiation detection element, each time at a different time, to the detection threshold where the emitted electromagnetic radiation is emitted from one end of the hopper accessible to the user.

37. A method for detecting a supplied object, according to claim 36, characterized in that the emission of electromagnetic radiation emits radiation by pulses.

38. A method for detecting a supplied object, according to claim 36, characterized in that the emission of electromagnetic radiation emits continuous radiation.

39. A method for detecting a supplied object, according to claim 36, characterized in that the selection of the detection threshold is a dynamic selection that compensates for variations in the electromagnetic radiation in the detection region but is slow in relation to the time interval for which the supplied object traverses the beam of electromagnetic radiation.

40. A method for detecting a supplied object, according to claim 37, characterized in that the pulse width or the pulse radiation is selected during the calibration of the detection of a supplied object.

41. A method for detecting a supplied object, according to claim 37, characterized in that the calibration is one of a group of calibrations consisting of: a complete calibration, a calibration without limit, a limited calibration, and a calibration check, the Complete calibration comprises resetting all stored system variables, initializing a pulse width to a predetermined minimum value, pulse width is twice a detected width of pulsed radiation, and increasing the pulse width by a pulse width quantum preselected at least a first preselected number of consecutive pulses are received by the electromagnetic radiation detection element with a pulse width variance smaller than a first preselected variance limit, the calibration without limit comprises initializing the pulse width to a stored pulse width currently decreased by a preselected pulse width, and increasing the pulse width by a preselected pulse width amount until at least a preselected number of consecutive pulses are received by the electromagnetic radiation detection element with a pulse width variance less than a second preselected limit of variance, the limited calibration comprises initializing the pulse width to the currently stored pulse width decreased by a quantum of preset pulse width, and increase the pulse width by a preselected pulse width quantum until at least the first preselected number of consecutive pulses are received by the electromagnetic radiation detection element with the pulse width variance smaller than the second preselec variance limit tion, wherein the base signal which is a composite light intensity signal that combines ambient and excitation light, is varied within a range . »^ _ * I '-.?. ____ signal variation base preselected, and a force of a modulation signal pulse width is varied within a range of variation of modulation signal pulse width, calibration check indicates proper operational status of a detection device used for the method of detecting an object supplied by the reception of at least one second preselected number of consecutive pulses by the sensing element of electromagnetic radiation with a variance of width pulse less than a third limit variance preselected, where it changes the baseband signal, within the range of variation of the base signal preselected, and strength of the modulation signal pulse width is varied within of a range of preset pulse width modulation signal variation.

42. A method for detecting a supplied object, according to claim 41, characterized in that the pulse width has a preselected maximum value.

43. A method for detecting an object supplied in accordance with claim 42, wherein the first limit preselected variance is smaller than the second limit variance preselected, and the second limit preselected variance is smaller than the third limit variance preselected.

44. A method for detecting a supplied object, according to claim 43, characterized in that the first preselected variance limit is approximately one microsecond, the second preselected variance limit is approximately two microseconds, and the third preselected variance limit is approximately three microseconds.

45. A method for detecting a supplied object, according to claim 42, characterized in that the predetermined minimum value of the pulse width is approximately sixteen microseconds and the preselected maximum value of the pulse width is approximately fifty microseconds.

46. A method for detecting a supplied object, according to claim 45, characterized in that the preselected pulse width quant is about one microsecond.

47. The method for detecting a supplied object, according to claim 41, characterized in that the second preselected number of consecutive pulses is smaller than the first preselected number of consecutive pulses.

48. A method for detecting a supplied object, according to claim 41, characterized in that the first preselected number of consecutive pulses is approximately one hundred sixty, in the second preselected number of consecutive pulses it is approximately sixty four.

49. The method for detecting a supplied object, according to claim 41, characterized in that the range of preset base signal variation is about 10% less than about 10% greater than a base signal value stored in a calibration immediately previous.

50. The method for detecting a supplied object, according to claim 41, characterized in that the range of variation of the preselected pulse width modulation signal is from about 10% less than about 10% greater than a modulation signal value of pulse width stored in an immediately previous calibration.

51. A method for detecting a supplied object, according to claim 41, characterized in that the unlimited calibration is performed by activating a detection device used for the method of detecting a supplied object when the detection device has been turned off for more than approximately five minutes .

52. A method for detecting a supplied object, according to claim 41, characterized in that the unlimited calibration is performed by activating a detection device used for the detection method of a supplied object when the temperature has changed by at least about C (two degrees Fahrenheit) in relation to the ambient temperature recorded in a previous calibration.

53. The method for detecting a supplied object, according to claim 41, characterized in that the limited calibration is performed by activating a detection device used for the detection method of a supplied object when the time from the immediately preceding calibration is between approximately three minutes and approximately five minutes.

54. The method for detecting a supplied object, according to claim 41, characterized in that full calibration is performed when selected during the service delivery of a detection device used for the method of detecting a supplied object.

55. The method for detecting a supplied object, according to claim 41, characterized in that the calibration verification is performed immediately after the object is supplied.

56. The method for detecting a supplied object, according to claim 41, characterized in that one of a plurality of error signals is activated when a detection device is used when the method for detecting a supply object fails in at least one calibration of the calibration group.

57. The method for detecting a supplied object, according to claim 56, characterized in that the plurality of error signals corresponding to insufficient light, too much light, lack of signal, a poor quality signal, a drastic environmental displacement and an error of fatal detector, respectively.