Patent Description:
Self-facing retail merchandise displays are generally known in the art. Once such typical display includes one or more pusher assemblies which may for example be situated on a retail merchandise shelf. A conventional pusher assembly incorporates a pusher that rides along an elongated track. The track may be a single drop in track with a single pusher slidable thereon, or it may be a structure defining multiple tracks for receipt of respective pushers. A spring is connected between the pusher and a leading edge of the track. The spring acts to bias the pusher forward along the track towards the leading edge thereof. A given display may utilize multiple pusher assemblies arranged generally in parallel to on another.

A user can retract the pusher away from the leading edge of the track and position items of retail merchandise (also referred to herein as products) in a linear row on top of the track and uncoiled portion of the spring, between the leading edge of the track and the pusher. The biasing force provided by the spring and exerted upon the pusher serves to bias the linear row of retail merchandise forward to ultimately "front face" the merchandise.

That is, when a customer removes the leading most item of merchandise from the linear row of merchandise, the pusher will be drawn forward by the spring to index the row of merchandise forward so that the next item of merchandise in the row is positioned proximate the leading edge of the track in an aesthetically pleasing manner. Such automatic front facing eliminates the necessity for retail store employees to manually face the merchandise, and thus ultimately reduces the cost of labor of the retailer.

The aforementioned pusher systems have been utilized in various retail display environments. One example is a retail shelf. Typically, a plurality of pusher bodies and their corresponding tracks are arranged in a side by side manner along the shelf. Each pusher and its corresponding track are separated by dividers to maintain a plurality of generally straight rows of merchandise that run from the front to the back of the shelf. Such a familiar configuration can be found in many retail stores for selling hygiene items such as deodorant, as one example.

In another configuration, the pusher system may be embodied as a stand-alone pusher tray. These trays may include means for mounting the tray as a cantilevered extension from another structure, such as a bar. These trays may also be situated directly on a retail shelf. Further, these trays may include side barriers which are adjustable so as to accommodate merchandise of differing widths. Examples of these trays may be readily seen at <CIT>,<CIT>, <CIT>, <CIT>.

<CIT> relates to systems, apparatus, methods, computer readable media, and computer program products for implementing a wireless shelf pusher activity detection system. The apparatus is a monitoring device for monitoring theft or sales activity associated with a product pusher device. The monitoring device may include a sensor configured to detect movement of a pusher member of the product pusher device, a wireless communications interface, and a processor. The processor may be configured to receive at least one sensor signal from the sensor indicating movement of the pusher member, determine a product movement activity type based on characteristics of the at least one sensor signal, and generate, for transmission via the wireless communications interface, a pusher activity message indicating the product movement activity type.

<CIT> discloses an inventory shelf monitoring system which includes a plurality of track systems located on at least one shelf of a retail or warehouse establishment. Each track system includes a sensor and actuator that determines the position of a product pusher. The identity and location of the product pusher, for each track system on the at least one shelf, is sent to a data acquisition and transmitter circuit that assembles, formats, and transmits pusher position data to a central receiver, which receives corresponding data from all shelves employing the system in the retail or warehouse establishment.

Loss prevention is a continuing problem in the retail industry. Current anti-theft systems involve locking up merchandise behind counters that are far away from other related merchandise, or locking up the merchandise in secure cabinets that are closer to where the related merchandise is generally stored.

Heretofore, there have been limited attempts at incorporating anti-theft technology into pusher systems themselves. Such attempts, while sufficient for a majority of loss prevention scenarios may not detect very small movements of the pusher, e.g. where very small merchandise is contained in the pusher system such that removal of one item or even several creates a very small movement in the pusher.

Other challenges arise in self-facing retail merchandise displays with regard to inventory management. Because the merchandise contained in such displays is typically high purchase volume merchandise, e.g. deodorants, razor blades, medicines, etc., it is not uncommon for one or more rows of the display to become completely empty for some time before being restocked. Accordingly, such displays must be routinely inspected by store personnel to ensure that they have adequate stock levels. This inspection may be overlooked from time to time in the event the store is understaffed, or adequately staffed but very busy. Such manual inspection, while necessary, diverts store personnel from other potentially more pressing activities such as customer service.

Accordingly, there exists a need in the art for a retail merchandise pusher display, pusher assembly, and pusher incorporating a system for retail stores that will deter theft and enhance inventory management of such displays.

The invention provides a retail merchandise pusher according to claim <NUM>. The pusher is configured for sliding along a track of a pusher assembly, where the pusher assembly is mountable to a retail merchandise shelf. The pusher includes a housing, a spring drum rotatably mounted within the housing, and a coil spring mounted to the spring drum. The coil spring is coilable and uncoilable upon rotation of the spring drum. A controller is coupled to a sensor arrangement carried within the housing. The sensor arrangement includes a spring drum sensor for detecting rotation of the spring drum. A direction sensor detects a direction of rotation of the spring drum, while an incremental distance sensor detects an incremental movement of the pusher. The controller is configured to calculate, based on data from the sensor arrangement, a total distance and direction of travel by the pusher, and also configured to generate an alarm when the pusher travels more than a threshold distance within a predetermined period of time.

In a particular embodiment, the alarm is at least one of a visual, audible, or RF signal. The controller may be coupled to an output device disposed in the housing, where the output device is configured to produce the alarm as a visual or audible signal. Furthermore, the controller may be coupled to a transmitter disposed in the housing, where the transmitter is configured to wirelessly transmit data to a remote receiver. The aforementioned data includes at least one of an alarm status, and the total distance and direction of travel by the pusher.

In particular embodiments, the controller is configured to transmit information, based on data from the sensor arrangement, wherein the information includes an inventory status for the pusher assembly. As used in this application, the term "inventory status" or "stock status" relates to the number of merchandise items remaining in a particular pusher assembly. The movement of the pusher, which may indicate either the replenishment or the removal of goods from the pusher assembly, typically results in a change of the inventory status for the pusher assembly. In more particular embodiments, the controller comprises a microprocessor.

The spring drum sensor includes a pair of opposed electrical contacts and a tab extending from the spring drum, the tab rotatable with the spring drum, wherein the tab is arranged to bias one of the pair of opposed electrical contacts into contact with the other one of the pair of the opposed electrical contacts at each complete revolution of the spring drum.

In other embodiments, the direction sensor includes a first electrical contact, a common electrical contact, and a second electrical contact, the common electrical contact interposed between the first electrical contact and the second electrical contact. In a further embodiment, a distal end of common electrical contact is intermittently in contact with gear teeth formed on an outer periphery of the spring drum such that the common electrical contact is biased by the gear teeth into contact with the first electrical contact when the spring drum rotates in a first direction, and biased by the gear teeth into contact with the second electrical contact when the spring drum rotates in a second rotational direction opposite the first rotational direction.

In certain embodiments, the incremental distance sensor includes a sensing gear in contact with the spring drum, and a slotted disc mounted to the sensing gear, the incremental distance sensor further comprising a light sensor arrangement configured to produce and detect a beam of light. In a further embodiment, a peripheral region of the slotted disc is movable through a sensing region through which the beam of light extends, wherein the peripheral region includes a plurality of slots formed therein, wherein the plurality of slots sequentially pass through the sensing region as the sensing gear rotates such that the beam of light alternately passes through and is blocked by the plurality of slots. The light sensor arrangement may include a light emitter located on a first side of the slotted disc, and a light sensor located on a second side of the slotted disc opposite the first side, the light sensor arranged to detect the beam of light emitted by the light emitter.

In more particular embodiments, the light emitter is arranged to emit the beam of light such that it is perpendicular to a plane of rotation defined by the slotted disc. In other embodiments, the coil spring is configured to bias the housing toward one end of the track. Further, the pusher may be configured to permit a user to set or adjust at least one of the threshold distance and the predetermined period of time. In some embodiments, the pusher includes a reset control to set a zero position for the controller, the zero position indicating that no merchandise is contained in the pusher assembly such that the pusher is at an end of the track.

The invention provides a pusher assembly according to claim <NUM>. The pusher assembly is configured for mounting to a retail shelf, the shelf having a front and a back, wherein retail merchandise situated near the front of the shelf is removable from the pusher assembly. The pusher assembly includes a track, and a retail merchandise pusher according to the invention, the pusher mounted to the track. The pusher is slidable toward and away from the front of the shelf. The pusher includes a controller coupled to a sensor arrangement for detecting movement and a direction of travel by the pusher. The controller is configured to calculate, based on data from the sensor arrangement, a total distance traveled by the pusher along the track. The controller is further configured to generate an alarm when the pusher travels more than a threshold distance within a predetermined period of time.

According to the invention, the sensor arrangement includes a spring drum sensor, a direction sensor, and an incremental distance sensor. According to the invention, the spring drum sensor includes a pair of opposed electrical contacts and a tab extending from a rotatable spring drum of the pusher, the tab rotatable with the spring drum, wherein the tab is arranged to bias one of the pair of opposed electrical contacts into contact with the other one of the pair of the opposed electrical contacts at each complete revolution of the spring drum.

In another embodiment, the direction sensor includes a first electrical contact, a common electrical contact, and a second electrical contact, the common electrical contact interposed between the first electrical contact and the second electrical contact. The incremental distance sensor may include a sensing gear in contact with the spring drum the gear including a slotted disc mounted to the gear, the incremental distance sensor further comprising a light sensor arrangement configured to produce and detect a beam of light.

In certain embodiments, the alarm is at least one of a visual, audible, or RF signal, and the controller is coupled to a transmitter configured to wirelessly transmit data to a remote receiver. The aforementioned data includes at least one of an alarm status, and the total distance and direction of travel by the pusher. The pusher may be further configured to permit a user to set or adjust at least one of the threshold distance and the predetermined period of time, and to include a reset control to set a zero position for the controller. The zero position indicates that no merchandise is contained in the pusher assembly such that the pusher is at an end of the track. The controller may be configured to provide, based on data from the sensor arrangement, an inventory status of the pusher assembly.

The invention provides a retail merchandise display system according to claim <NUM> for self-facing retail merchandise. The retail merchandise display includes a shelf, and at least one pusher assembly according to the invention mounted to the shelf. The at least one pusher assembly includes a track, and a pusher slidable along the track. The pusher assembly includes a controller coupled to a sensor arrangement. The controller is configured to calculate, based on data from the sensor arrangement, a large-scale movement of the pusher, and an incremental movement by the pusher, where the controller is configured to generate a local alarm when a total distance traveled by the pusher, where the total distance is equal to a sum of the large-scale movement and the incremental movement, is greater or equal to a predefined distance. The pusher includes a transmitter operable to wirelessly communicate the total distance traveled by the pusher. A receiver is remotely located from the pusher, and configured to receive a wireless signal from the transmitter, and configured to generate a remote alarm in concert with the local alarm.

In certain embodiments, the local and remote alarms are at least one of visual or audible alarms. In other embodiments, the at least one pusher assembly includes a plurality of pusher assemblies, wherein each one of the plurality of pusher assemblies wirelessly communicate with the receiver. Still, in other embodiments, the receiver includes an RF receiver, an audio speaker, and a Wi-Fi module configured to transmit data received from the pusher. Further, the wireless signal may be an RF signal.

According to the invention, the sensor arrangement includes a spring drum sensor, a direction sensor, and an incremental distance sensor. Further, the receiver may be configured to transmit data received from the pusher to a computer or mobile device, such that the data allows the computer or mobile device to display information regarding the pusher assembly. Moreover, the information regarding the pusher assembly may include at least one of an alarm status, and inventory status, and a position of the pusher.

Turning now to the drawings, the same illustrate an exemplary embodiment of a retail merchandise display system that incorporates a pusher assembly. The pusher assembly includes a pusher which includes a new and inventive sensor arrangement for detecting and calculating relative small movements of the pusher. Such a configuration is highly advantageous for loss prevention and inventory management purposes, particularly loss prevention and inventory management of relatively small products.

Indeed, the high resolution of the distance detection of the pusher enables an accurate calculation of a number of products removed from the retail merchandise display in a single movement cycle or in a given period of time. For example, a movement cycle (i.e. a continuous movement of the pusher) reflecting a relatively long distance traveled by the pusher is indicative of a number of products removed in a single movement of the pusher. As another example, a large number of separate movement cycles during a relatively short period of time is also indicative of a number of products removed from the display. In either case, each is indicative of a potential theft event. The system described herein is operable to generate one or both of a local and a remote alarm when such potential theft conditions are met. Further, the system described herein also communicates the information it collects regarding pusher movement for purposes of managing the inventory of that particular pusher assembly.

With particular reference to <FIG>, the same illustrates an exemplary embodiment of a retail merchandise display system <NUM> (also referred to herein as display <NUM>). Display <NUM> included one or more pusher assemblies <NUM> mounted to a shelf <NUM>. Each pusher assembly <NUM> includes a pusher <NUM> that is slidable along a track <NUM>. Each pusher <NUM> houses a coil spring described below which attaches to shelf <NUM> directly, or as shown in the illustrated embodiment, to an external structure that in turn is mounted to shelf <NUM> such as a mounting rail <NUM>. The pusher <NUM> is biased by this coil spring <NUM> toward one end of the track <NUM>. In the embodiment shown, the pusher <NUM> is biased by this coil spring <NUM> toward the mounting rail <NUM>, i.e. from the back of shelf <NUM> toward the front of shelf <NUM>.

As described in greater detail below, pusher <NUM> houses a sensor arrangement which is operable to calculate the distance traveled by pusher <NUM> along track <NUM>, and to determine the direction of such travel, e.g. from the back to the front of shelf <NUM>, or from the front to the back of shelf <NUM>. In event that such movement is indicative of a potential theft event, pusher <NUM> is also operable to generate a local alarm at pusher <NUM>, and/or a remote alarm at a receiver <NUM> of display <NUM> located remotely from the remainder of display <NUM>. The term "alarm" as used herein should be taken to mean any audible or visual cue designed to draw attention to display <NUM>, such as beeps, tones, prerecorded messages, flashing or continuous lights, etc., but is also intended to include any electronic signal which could be used to serve as a warning. Such remote alarm functionality is particularly advantageous as receiver <NUM> may be located with security or other personnel that can readily respond to a potential theft event. The remote alarm generated by receiver <NUM> may be simultaneous and in concert with the local alarm generated by the pusher <NUM>.

Still referring to <FIG>, two pusher assemblies <NUM> are illustrated. However, display <NUM> may utilize fewer or greater pusher assemblies. Indeed, in the case of smaller products, a relatively large number of pusher assemblies <NUM> may be situated on shelf <NUM>. Further, display <NUM> may optionally also include a plurality of dividers <NUM> as shown, for keeping adjacent rows of product confined from one another. Each divider <NUM> may also include its own integrated front stop <NUM> as shown, for stopping the forward motion of products as they are biased by pusher <NUM>. Alternatively, a front stop may be mounted directly to shelf <NUM> (or be formed by the shelf itself) or alternatively to mounting rail <NUM>. With the foregoing description in hand, it will be readily recognized that mounting rail <NUM>, dividers <NUM>, and front stops <NUM> are optional components that may take on different forms or may be omitted entirely within the scope of the invention described herein.

Turning now to <FIG>, pusher assembly <NUM>, and particularly pusher <NUM>, is operable to bias products <NUM> forward, i.e. in direction <NUM> shown in <FIG>. The leading product <NUM> is removable from display <NUM> as shown. In a potential theft event, multiple or even all of products <NUM> may be removed in a single action, or in multiple quick successive actions. In either case, pusher <NUM> will move a relatively large distance forward in direction <NUM>. As introduced above and described below, pusher <NUM> is operable to determine the distance it has traveled, and generate an appropriate alarm when the distance is beyond a predetermine threshold. As discussed herein, the alarm may be a visual alarm, audible alarm, or electronic signal such as a wireless or RF signal which could serve as a warning to the system user. Further, the alarm may be any combination or all of the aforementioned types.

With reference to <FIG>, pusher <NUM> incorporates a new and inventive sensor arrangement for achieving the foregoing functionality. The topology shown in <FIG> depicts this sensor arrangement and additional componentry necessary to achieve the functionality herein. In particular, the sensor arrangement includes a spring drum sensor <NUM>, a direction sensor <NUM>, and an incremental distance sensor <NUM> which in combination determine the distance and direction traveled by pusher <NUM>. Each of the foregoing components of the sensor arrangement is in operable communication with a controller <NUM>. Controller <NUM> may for example be a microprocessor, or any other firmware, hardware, or software necessary to achieve the functionality herein.

Controller <NUM> is coupled to a local power supply <NUM> and an output device <NUM>. Local power supply <NUM> provides electrical power to the controller and/or sensor arrangement to achieve the operation described herein. Output device <NUM> produces the above-introduced local alarm, and as such, may be embodied as any device capable of producing such an alarm. As will be explained in more detail below, the controller <NUM> is configured to calculate, based on data from the sensor arrangement, a total distance and direction of travel by the pusher <NUM>, and to generate an alarm when the pusher <NUM> travels more than a threshold distance within a predetermined period of time. As will be explained below, the pusher <NUM> may include controls to allow the user to adjust the threshold distance and the predetermined period of time.

Controller <NUM> is also in communication with a transmitter <NUM> which wirelessly sends the distance and direction of travel information, alarm status, and any other information collected by controller <NUM> to receiver <NUM>, shown schematically in <FIG>. As used in this application, the term "alarm status" refers to whether or not an alarm is being triggered or has been triggered by the controller <NUM>. This wireless communication may use any known radio frequency (RF) communication protocol. The data transmitted from the controller <NUM> to the receiver <NUM> may include at least one or all of an inventory status, alarm status, and total distance and direction of travel by the pusher <NUM>. In at least one embodiment of the invention, there are a plurality of pusher assemblies <NUM>, wherein each one of the plurality of pusher assemblies <NUM> wirelessly communicates with the receiver <NUM>. In certain embodiments, the receiver <NUM> includes at least one of an RF receiver, an audio speaker, and a Wi-Fi module which is configured to wirelessly transmit data (e.g., as an RF signal) received from the pusher <NUM>.

Turning to <FIG>, the same illustrates pusher <NUM> in a partially exploded view. Pusher <NUM> includes an outer housing <NUM> that has been partially removed to reveal the interior componentry of pusher <NUM>. Pusher <NUM> carries a coil spring <NUM>. Coil spring <NUM> is mounted on a spring drum <NUM>. Spring drum <NUM> is rotatable about a shaft <NUM> to allow, in specific embodiments, an uncoiled portion of coil spring <NUM> to be paid out or retracted through an opening <NUM> formed in housing <NUM>.

As can be seen in <FIG>, spring drum <NUM> includes gear teeth 90a, 90b formed at opposed peripheral side edges of spring drum <NUM>. Gear teeth 90a are used to repeatedly actuate a portion of direction sensor <NUM> as described below. Gear teeth 90b mesh with a sensing gear <NUM> of incremental distance sensor <NUM> as shown. As described in greater detail below, sensing gear <NUM> includes a slotted disc <NUM> mounted to or formed integrally with sensing gear <NUM>.

Slotted disc <NUM> includes a plurality of slots <NUM> formed in a peripheral region thereof as shown. These slots successively block a beam of light of incremental distance sensor <NUM> as sensing gear <NUM> rotates. This action creates successive light pulses which are detected by incremental distance sensor <NUM> and used to measure the distance traveled by pusher <NUM> with a high resolution.

Each of the spring drum sensor <NUM>, direction sensor <NUM>, and incremental distance sensor <NUM> are coupled to a printed circuit board (PCB) <NUM> as shown to achieve the topology illustrated in <FIG>. Additionally, a reset control <NUM> which may be a button, switch, or dial, and threshold distance control <NUM> are also coupled to PCB <NUM> to achieve the functionality described herein. Thus, embodiments of the pusher <NUM> include the reset control <NUM> to set a zero position for the controller <NUM>, the zero position indicating that no merchandise is contained in the pusher assembly <NUM> such that the pusher <NUM> is at the front end of the track <NUM>.

With reference to <FIG>, when a portion of coil spring <NUM> is uncoiled and then is recoiled onto spring drum <NUM> by moving in direction <NUM>, spring drum <NUM> rotates in direction <NUM> as shown. Movement of coil spring <NUM> in direction <NUM> is indicative of pusher <NUM> moving toward the front of shelf <NUM> (see <FIG>, <FIG>), i.e. is indicative to a product or products <NUM> being removed from display <NUM>.

Due to the contact between spring drum <NUM> and sensing gear <NUM>, this causes sensing gear <NUM> and its associated slotted disc <NUM> to rotate in direction <NUM> as shown. Conversely, movement of spring <NUM> in direction <NUM> causes spring drum <NUM> to rotate in direction <NUM> as shown. Movement of coil spring <NUM> in direction <NUM> is indicative to usher <NUM> moving toward the back of shelf <NUM> (see <FIG>, <FIG>), i.e. is indicative of product or products <NUM> being restocked into display <NUM>. This in turn causes sensing gear <NUM> and slotted disc <NUM> to rotate in direction <NUM>.

Turning now to <FIG>, the operation of spring drum sensor <NUM> and direction sensor <NUM> will be described in greater detail. Turning first to spring drum sensor <NUM>, the same includes a pair of opposed electrical contacts <NUM>, <NUM> as shown. Contact <NUM> is coupled to PCB <NUM> by way of a housing <NUM>. Similarly, contact <NUM> is coupled via a housing <NUM> to PCB <NUM>. Each electrical contact <NUM>, <NUM> is generally flexible so that it may readily move into and out of contact with the other contact.

As spring drum <NUM> rotates, a radially protruding tab <NUM> mounted to a hub <NUM> of spring drum <NUM> rotates as well. Upon each full revolution of spring drum <NUM>, tab <NUM> will bias contacts <NUM>, <NUM> together. In the illustration of <FIG>, spring drum <NUM> is rotating in direction <NUM>, and thus tab <NUM> has biased contact <NUM> into contact with <NUM>.

Controller <NUM> is operable to detect when electrical contacts <NUM>, <NUM> are in contact with one another, and records this information. Two successive contacts between electrical contacts <NUM>, <NUM> signifies one full revolution of spring drum <NUM>, which corresponds to a linear movement of spring <NUM> and hence a linear movement of pusher <NUM>.

Direction sensor <NUM> is used to direction the rotational direction of spring drum <NUM> as movement is detected. Indeed, while two successive contacts of electrical contacts <NUM>, <NUM> provides an indication of a linear distance moved by pusher <NUM>, these contacts do not provide an indication of which direction pusher <NUM> was moving during that time. The operation of direction sensor <NUM> is thus used to correlate a direction with the movement detected.

Direction sensor <NUM> includes a first electrical contact <NUM>, a second electrical contact <NUM>, and a common electrical contact <NUM> interposed between first and second electrical contacts. Common electrical contact <NUM> is resiliently movable into contact with either one of first and second electrical contacts <NUM>, <NUM>. Each of these contacts, <NUM>, <NUM>, and <NUM> are insulated from one another via a housing <NUM>, and coupled to PCB <NUM>.

For example, as spring drum <NUM> rotates in direction <NUM> as shown, a distal end of common electrical contact <NUM> is intermittently but repeatedly contacted by the teeth of gear teeth 90a, and repeatedly brought into contact with first electrical contact <NUM>. Conversely, when spring drum <NUM> rotates in direction <NUM> (see <FIG>), common electrical contact <NUM> is repeatedly brought into contact with second electrical contact <NUM>. Controller <NUM> is operable to recognize that successive contact between common electrical contact <NUM> and first electrical contact <NUM> is indicative of pusher <NUM> moving toward the front of shelf <NUM> (see e.g. <FIG>, <FIG>). Conversely, controller <NUM> is also operable to recognize that successive contact between common electrical contact <NUM> and second electrical contact <NUM> is indicative of pusher <NUM> moving toward the rear of shelf <NUM> (see e.g. <FIG>, <FIG>).

It will be recognized, however, that spring drum sensor <NUM> can detect only large-scale movement of pusher. As used herein, "large-scale movement" means movement of pusher <NUM> which corresponds to one full revolution of spring drum <NUM>. In order to determine incremental movement of pusher <NUM>, incremental distance sensor <NUM> is employed. As used herein, "incremental movement" of pusher <NUM> means movement that is less than a large-scale movement. Indeed, in a single movement cycle, i.e. an uninterrupted movement of pusher <NUM>, the same may move some distance prior to and/or after the two successive contacts of contacts <NUM>, <NUM> that signifies one large-scale movement. Incremental distance sensor <NUM> is thus used to determine this additional distance.

With reference to <FIG> and <FIG>, incremental distance sensor <NUM> includes the aforementioned sensing gear <NUM> and slotted disc <NUM>, which are rotatable about an axis defined by shaft <NUM> upon a corresponding rotation in spring drum <NUM>. Incremental distance sensor <NUM> also includes a light sensor arrangement comprising a light emitter <NUM> aimed at a light receiver <NUM> for detecting the presence or absence of a beam of light emitted from emitter <NUM>. Emitter <NUM> and receiver <NUM> are mounted to a housing <NUM> as shown. Housing <NUM> includes a slot <NUM> which defines a sensing region. The peripheral region of slotted disc <NUM> rotates through this sensing region. The slots <NUM> thereby successively interrupt the beam of light from emitter <NUM>.

As a result, receiver <NUM> detects pulses of light. Due to the equally spaced and regular arrangement of slots <NUM>, these pulses thus each correspond to a small linear movement of pusher <NUM>. Put differently, the pulses can be summed at controller <NUM> so as to determine a total distance moved by pusher <NUM> in any given movement cycle. Due to this very fine measurement, the resolution of distance measurement of pusher <NUM> is relatively high. As such, even very minor movements of pusher <NUM> corresponding for example very thin products <NUM> being removed can be detected. It will be recognized that incremental distance sensor <NUM> thus functions as a rotary encoder used for linear distance measurement.

The following provides an example of the distance measurement functionality of pusher <NUM>. In this particular example, the gear ratio between spring drum <NUM> and sensing gear <NUM> is <NUM>:<NUM>. Spring drum <NUM> has an outer diameter of <NUM>. As a result, one full revolution of spring drum <NUM> as detected by spring drum sensor <NUM> corresponds to <NUM> (i.e. <NUM>*pi* <NUM>). Also in this example, there are <NUM> slots <NUM> formed on slotted disc <NUM>. As such, one full revolution of slotted disc <NUM> generates <NUM> light pulses. Due to the aforementioned <NUM>:<NUM> gear ratio, one full revolution of spring drum <NUM> will cause four full revolutions of slotted disc <NUM>, and hence <NUM> light pulses for every one full revolution of spring drum <NUM>. Dividing the circumference of spring drum <NUM> by this total number of pulses, (i.e. <NUM>/<NUM> pulses) each pulse therefor corresponds to <NUM> of linear movement.

For the purposes of this example, it will be assumed that pusher <NUM> has moved <NUM> in a movement cycle. From start to finish in this movement cycle, pusher <NUM> will first move some distance prior to contacts <NUM>, <NUM> making their first contact. These contacts <NUM>, <NUM> will then make a second contact after spring drum <NUM> completes a full revolution (i.e. a revolution as measured by a first and a second contact of contacts <NUM>, <NUM>). Contacts <NUM>, <NUM> will then make a third contact after another full revolution of spring drum <NUM> (i.e. as measured by the third contact of contacts <NUM>, <NUM> occurring after the aforementioned second contact). Pusher will then move some distance after this third contact.

During the aforementioned movement, incremental distance sensor <NUM> sensed pulses of light. Assume for this example <NUM> pulses were detected prior to the first contact of contacts <NUM>, <NUM>, this distance portion correlates to a distance of <NUM>*<NUM> or <NUM>. Also assume for this example that <NUM> pulses were detected after the third contact of contacts <NUM>, <NUM>, this distance portion correlates to a distance of <NUM>*<NUM> or <NUM>. Also, as already mentioned, three total contact events between contacts <NUM>, <NUM> were detected, which amounts to two full revolutions of spring drum <NUM>, correlating to a distance portion of <NUM>. Summing the aforementioned distance portions, a total travel distance of approximately <NUM> has been detected.

In terms of loss prevention, the user can set an alarm threshold distance using threshold distance control <NUM> which may be a button, switch, dial, or any similarly suitable means for setting the alarm threshold distance. This threshold distance is the distance in a movement cycle observed by pusher <NUM> in which an alarm will be generated. The pusher <NUM> may include a control, similar to the threshold distance control <NUM>, which allows the user to adjust a time period during which the alarm threshold distance must be exceeded in order to generate the alarm. All distance measurements and alarm conditions can be transmitted to receiver <NUM>. Further, receiver <NUM> may be in communication with or embody inventory management software such that in addition to loss prevention, each pusher assembly <NUM> can also communicate information regarding its stock status, etc. As such, receiver <NUM> may incorporate or be in communication with a user interface for inputting an alarm threshold and/or a product depth as discussed below. In general, the capability of high resolution distance measurement can be used for anti-theft and inventory management functions.

Referring back momentarily to <FIG>, in terms of inventory management, the data communicated by each pusher <NUM> is also associated with a unique location identifier for each pusher. This enables the inventory management software to differentiate between the various pushers <NUM> in the system, and monitor the inventory of each. As such, a user can also define a product size for, i.e. depth, for one item of product in the pusher assembly <NUM>. The pusher <NUM> may then correlate the locally at controller <NUM>, or remotely at receiver <NUM> or any inventory management software integrated with or in communication with receiver <NUM>, the distance it has traveled to a number of products removed from pusher assembly <NUM>. As an example, a user may indicate that a single item has a <NUM>,<NUM> (one inch) depth. A movement of ten inches, therefore, amounts to ten products being removed. A user may set this minimum product depth using threshold distance control <NUM>, or they may set it at receiver <NUM> or the inventory management software embedded in or associated therewith. The threshold distance control <NUM> may be a dial, button, switch, or any suitable means for setting the minimum product depth.

Turning now to <FIG>, the same illustrates the basic control logic of each pusher assembly <NUM>. Starting at step <NUM>, each pusher <NUM> must be "zeroed" by activating its reset control, such as a switch, dial, or button, when no product <NUM> is loaded therein, i.e. when coil spring <NUM> has drawn pusher <NUM> as close as is possible to the front of shelf <NUM>. This is recorded at step <NUM> as the zero position. Thereafter, pusher <NUM> remains in sleep mode at step <NUM> until motion is detected at <NUM>. Upon this detection, pusher <NUM> exits sleeps mode and monitors and calculates the distance it has moved at step <NUM> using the sensor arrangement described above.

At step <NUM> a determination is also made as to whether pusher <NUM> is moving up (i.e. toward the front of shelf <NUM>) or down (i.e. toward the rear of shelf <NUM>). If moving down, the process loops back to step <NUM>. If moving up, the process continues to step <NUM> where a determination of whether the fist rotation marker (i.e. a contact of contacts <NUM>, <NUM>) has been detected. If yes, this information is updated at step <NUM>. After step <NUM>, or if no contact of contacts <NUM>, <NUM> is detected, the process moves on to step <NUM> and records the distance moved forward. This distance is then analyzed at step <NUM> to see if it is greater than a first threshold, i.e. a "beep" threshold where only a temporary alarm is generated. If it is not greater than this threshold, at step <NUM> transmitter <NUM> then sends RF data corresponding to the original position of pusher <NUM>, the distance pusher <NUM> moved, the direction pusher <NUM> moved, and an alarm status.

If, however, at step <NUM> the distance moved is such that the temporary alarm should be generated, at check is performed at step <NUM> to confirm whether or not the distance moved is great enough to warrant a full alarm. If yes, at step <NUM> the alarm status is saved and an alarm of five seconds in duration is generated at step <NUM>. If, at step <NUM> it is determined that the alarm threshold has not been met, then an additional check at step <NUM> is performed to determine whether the threshold at step <NUM> has been exceeded within a time period of ten seconds. If no, the temporary alarm status is saved at step <NUM> and only the temporary alarm is generated at step <NUM>. At the end of either of steps <NUM> or <NUM>, RF information is sent at step <NUM>.

If the check at step <NUM> is no, or if either of steps <NUM> or <NUM> are completed, the process then proceeds to step <NUM>, to determine whether the pusher is at its previously-set zero position. If yes, then the foregoing steps are repeated as necessary upon movement of pusher <NUM>. If not, the process moves onto step <NUM> where pusher <NUM> returns to sleep mode. Pusher <NUM> exits sleep mode at step <NUM> and monitors and calculates the distance it has moved at step <NUM>. A determination at step <NUM> is conducted to determine whether the pusher has moved up or down in the same manner as described above relative to step <NUM>. If moving up, the process proceeds to step <NUM> and continues as described above. If moving down, this distance is recorded at step <NUM>. A determination is then made at step <NUM> as to whether pusher <NUM> has returned to its zero position. If so, it is recorded at step <NUM> that the pusher is at its zero position, and the process continues to step <NUM>. If not, nothing is recorded and the process continues to step <NUM>.

Claim 1:
A retail merchandise pusher (<NUM>) configured for sliding along a track (<NUM>) of a pusher assembly (<NUM>), the pusher assembly (<NUM>) mountable to a retail merchandise shelf (<NUM>), the pusher comprising:
a housing (<NUM>);
a spring drum (<NUM>) rotatably mounted within the housing (<NUM>);
a coil spring (<NUM>) mounted to the spring drum (<NUM>), the coil spring (<NUM>) coilable and uncoilable upon rotation of the spring drum (<NUM>); and
a controller (<NUM>) coupled to a sensor arrangement carried within the housing (<NUM>), the sensor arrangement comprising:
a spring drum sensor (<NUM>) for detecting rotation of the spring drum (<NUM>);
a direction sensor (<NUM>) for detecting a direction of rotation of the spring drum (<NUM>); and
an incremental distance sensor (<NUM>) for detecting an incremental movement of the pusher (<NUM>);
wherein the controller (<NUM>) is configured to calculate, based on data from the sensor arrangement, a total distance and direction of travel by the pusher (<NUM>), and to generate an alarm when the pusher (<NUM>) travels more than a threshold distance within a predetermined period of time, characterized in that the spring drum sensor (<NUM>) includes a pair of opposed electrical contacts (<NUM>, <NUM>) and a tab (<NUM>) extending from the spring drum (<NUM>), the tab (<NUM>) rotatable with the spring drum (<NUM>), wherein the tab (<NUM>) is arranged to bias one of the pair of opposed electrical contacts (<NUM>, <NUM>) into contact with the other one of the pair of the opposed electrical contacts (<NUM>, <NUM>) at each complete revolution of the spring drum (<NUM>).