Abstract:
Systems and techniques for a scanner having a top plate with an integrated scale. A scanner base mates with a scanner top plate assembly, with the top plate assembly including an integrated scale. The top plate assembly includes a scan window and a scale mechanism. The top plate rests on or is secured to suitable resting points in the scanner base. The top plate suitably receives power, and communicates measurement data to the scanner base, without the use of cables or other connectors whose weight may interfere with accurate reading of weight. A scanner base may be designed so as to accommodate any of a variety of alternative scanner top plate types without reconfiguration, or with a relatively simple reconfiguration of the scanner base.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to improvements to retail scanner scale systems. More particularly, the invention relates to improved systems and techniques for performing weight measurement using a top plate assembly for a scanner scale system and communicating weight measurements to the scanner base without attachments that risk affecting weight readings. 
   BACKGROUND OF THE INVENTION 
   Present day retail systems frequently employ bar code scanner scale systems. Scanner scale systems typically include scale hardware deployed in the scanner base. Such integration of scale hardware imposes significant constraints on design of scanner scale systems. The scanner base must provide physical space for the scale components, and the enclosure and mechanical elements of the scanner base must be constructed so as to support the scale weighing plate and any loads that may be placed on the weighing plate. The physical space needed for the scale components imposes size requirements on a scanner in order to accommodate the scale components and the optical paths required to generate scan beams and for reflected light directed into the scanner for processing. In addition, the integration of scale components into the scanner base, as required by prior art techniques, limits the flexibility of scanner designs. Not all customers using console scanners need scale features. However, if scale capability is integrated into the base of a scanner, it is difficult or impossible to provide a single design that can be modified in order to be sold with or without scale capability. 
   SUMMARY OF THE INVENTION 
   Among its several aspects, the present invention addresses such difficulties by providing for a scanner top plate assembly with an integrated scale, and a scanner base suitable for mating with the top plate assembly. The top plate assembly includes a scan window and a measuring device, such as one or more load cells or strain gauges. The top plate assembly rests on or is secured to suitable resting points in the scanner base. The top plate assembly suitably receives power, and communicates measurement data to the scanner base, without the use of cables or other connectors whose weight may interfere with accurate reading of weight. A scanner base may be designed so as to accommodate any of a variety of alternative scanner top plate assemblies without reconfiguration, or with relatively simple reconfiguration of the scanner base. 
   A more complete understanding of the present invention, as well as further features and advantages of the invention, will be apparent from the following Detailed Description and the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIGS. 1A-1E  illustrate various alternative combinations of a scanner top plate assembly and a scanner base according to aspects of the present invention; 
       FIGS. 2A-2D  illustrate additional details of various scanner top plate assemblies according to aspects of the present invention; 
       FIG. 3  illustrates additional details of a scanner base according to an aspect of the present invention; and 
       FIG. 4  illustrates a process of scanner assembly and use according to an aspect of the present invention. 
   

   DETAILED DESCRIPTION 
     FIG. 1A  illustrates a scanner  100  according to an aspect of the present invention. The scanner  100  includes a scanner base  102  and a scanner top plate assembly  104 . The scanner top plate assembly  104  is removable from the scanner base  102 , and the scanner base  102  and scanner top plate assembly  104  are shown here as separated from one another for clarity of illustration and to afford a view into the scanner base  102 . The scanner top plate assembly  104  includes a generally flat top plate  105  on which objects may be placed for weighing, and in which a horizontal scan window  106  is disposed. The scanner base  102  includes a housing  107  and a vertical scan window  108 . The scanner top plate assembly  104  houses a scale mechanism  110  in the interior of the scanner top plate assembly  104 , as well as a scale support unit  112  for conditioning power for the scale mechanism  110  and controlling and providing communications to and from the scale mechanism  110 . The scanner top plate assembly  104  includes four rest points  114 A- 114 D for resting the scanner top plate assembly on four corresponding support points  116 A- 116 D of the scanner base  102 . In the example illustrated here, the support point  114 A and the rest point  116 A conduct electrical power to the scale support unit  112 , which in turn supplies necessary power to the scale mechanism  110 . The rest point  114 D and the support point  116 D provide a communication pathway between the scale support unit  112  of the scanner top plate assembly  104  and a top plate assembly control and communication interface  118  in the scanner base  102 . 
   In addition to the top plate assembly control and communication interface  118 , the scanner base  102  also includes conventional optical elements for generating one or more scan patterns and directing light that is reflected back into the scanner, in order to extract bar code information. These elements are not shown here in the interest of simplicity and to avoid obscuring the elements used to achieve support and communication with the top plate assembly  104 . The scanner base  102  also includes a bar code processing unit  120  for processing signals generated by reflection of scan patterns from bar codes, in order to extract bar code information, as well as a terminal interface unit  122  for managing communications with a transaction processing terminal with which the scanner  100  may be used. 
   The top plate assembly control and scale support interface  118  exercises such control as is needed over the operation of the scale support unit  112  and the scale mechanism  110 , and receives and processes weight signals received from the scale support unit  112 . Control may include requesting activation or deactivation of the scale mechanism  110 , requesting that the weight reading be in one format or another, or any other control desired. 
   The scanner base  102  may also include a wireless power transmission unit  128  and a wireless scale communication interface  130 . The wireless power transmission unit  128  and the wireless scale communication interface  130  are optional and their presence or absence, and their specific design and configuration, depends on design choices made for the scanner base  102  and the scanner top plate assembly  104 . Details of various possible wireless power transmission units  128  and wireless scale communication interfaces  130 , as well as additional details of the top plate assembly control and communication interface  118 , are discussed below. The scanner base  102  may also suitably include a light emitting diode (LED)  132 , in order to provide a light source for powering top plate assemblies with onboard solar cells. Such top plate assemblies are discussed further below. 
     FIG. 1B  illustrates an alternative scanner  140 , combining the scanner base  102  with an alternative scanner top plate assembly  142 . The various elements  107 ,  108 ,  116 A- 116 D,  118 ,  120 ,  122 ,  128 ,  130  and  132  are all illustrated here, because the scanner base  102  may suitably include all elements necessary to communicate with a number of different top plate assemblies, to simplify the process of interchanging top plate assemblies. 
   The top plate assembly  142  includes the top plate  105 , the window  106 , the scale mechanism  110 , the scale support unit  112  and the rest points  114 A- 114 D. However, the top plate assembly  142  does not include wired connections between the scale support unit  112  and the rest points  114 A and  114 D. Instead, the top plate assembly includes an onboard battery  144  and a wireless communication unit  146 . The onboard battery  144  powers the scale mechanism  110  and the scale support unit  112  independently of the scanner base  102 . The wireless communication unit  146  communicates with the wireless scale communication interface  130 . The exemplary wireless communication unit  146  illustrated here is an infrared communication device. As will be seen by the additional examples discussed below, various alternative power elements and communication devices may be used in various implementations of a top plate assembly, and the scanner base  102  may suitably support any of the different alternatives to simplify interchangeability. For example, the wireless communication unit  146  may be replaced by a radiofrequency device as illustrated in  FIG. 1C , a device employing reflected backscatter of radiofrequency transmissions, a BLUETOOTH® communication device, a device employing inductive coupling as illustrated in  FIG. 1D , or any of a number of alternative devices and techniques. 
     FIG. 1C  illustrates an alternative scanner  150 , combining the scanner base  102  with an alternative scanner top plate assembly  152 . The various elements  102 ,  107 ,  108 ,  116 A- 116 D,  118 ,  120 ,  122 ,  128 ,  130  and  132  are all illustrated here. 
   The top plate assembly  152  includes the top plate  105 , the window  106 , the scale mechanism  110 , the scale support unit  112  and the rest points  114 A- 114 D. However, the top plate assembly  152  does not include wired connections between the scale support unit  112  and the rest points  114 A and  114 D. Instead, the top plate assembly includes a solar cell  154  and a wireless communication unit  156 . The solar cell  154  powers the scale mechanism  110  and the scale support unit  112 . Depending on the specific implementation of the top plate assembly  152 , the solar cell  154  may receive light from the LED in the scanner base  102 , or from an ambient light source, such as the lights of an establishment in which the scanner  150  is used. 
   The wireless communication unit  156  communicates with the wireless scale communication interface  130 . In the example illustrated here, the wireless communication unit is a radiofrequency (RF) device. It will be recognized, however, that numerous different alternative combinations of power elements and wireless communication elements may be used, and the various combinations in the examples of  1 A- 1 D are exemplary. 
     FIG. 1D  illustrates an alternative scanner  160 , combining the scanner base  102  with an alternative scanner top plate assembly  162 . The various elements  102 ,  107 ,  108 ,  116 A- 116 D,  118 ,  120 ,  122 ,  128 ,  130  and  132  are all illustrated here. 
   The top plate assembly  162  includes the top plate  105 , the window  106 , the scale mechanism  110 , the scale support unit  112  and the rest points  114 A- 114 D. However, the top plate assembly  162  does not include wired connections between the scale support unit  112  and the rest points  114 A and  114 D. Instead, the top plate assembly  162  includes an inductive coupling unit  164  for receiving power from and performing communication through inductive coupling with a mating inductive coupling device provided in the wireless power transmission unit  128  of the scanner base  102 . While an inductive coupling unit  164  is illustrated here as providing both power and communication, it will be recognized that an inductive coupling may be used for power only, with a separate device employing different techniques being used for communication. Alternatively, two separate inductive coupling units may be used. Furthermore, if desired, an inductive coupling unit may be used for communication while a different technique is used for power. 
     FIG. 1E  illustrates a further alternative scanner  170 , combining the scanner base  102  with an alternative scanner top plate assembly  172 . The various elements  102 ,  107 ,  108 ,  116 A- 116 D,  118 ,  120 ,  122 ,  128 ,  130  and  132  are all illustrated here. 
   In the present example, however, the top plate assembly  172  does not include any scale capabilities, and simply includes the top plate  105  and the window  106 . The scanner  170  can be supplied to a customer who does not need scale capabilities and can be expected to carry a lower cost than a scanner with scale capabilities. 
     FIG. 2A  is a diagram of the scanner top plate assembly  104 , showing the various elements of the scanner top plate assembly  104  in block form. The scanner top plate assembly  104  includes the scale mechanism  110 , suitably implemented as a load cell. A load cell is a set of strain gauges, typically arranged in a bridge configuration. However, any number of alternative implementations may be employed and the particular implementation used for the scale mechanism  110  does not affect the use of the invention. The scale mechanism  110  suitably generates an analog weight signal. This signal may be supplied directly to the scanner base  102  through a rest point connection, such as the contact of the rest point  114 D and the support point  116 D, but may alternatively be amplified, converted to digital format or otherwise processed for use by the scanner base  102 . In addition, as discussed further above and below, this information may be wirelessly transmitted from the scanner top plate  104  to the scanner base  102 . 
   The scanner top plate assembly  104  also includes the scale support unit  112 . It will be recognized, however, that a scanner top plate assembly may be designed so that the scale mechanism simply provides an analog weight signal available at all times for interpretation and use by the scanner base  102 . 
   In the example illustrated here, the scale support unit  112  includes a control unit  202 , an amplifier  204  and an analog to digital converter  206 . The control unit  202  receives and acts on commands received from the scanner base  102  and directs the operation of the scale support unit  112  and the scale mechanism  110 . The amplifier  204  amplifies an analog signal produced by the scale mechanism  110  and the analog to digital converter  206  receives the amplified analog signal and generates a digital weight signal. The scale support unit  112  also controls power to the scale mechanism  110 , typically based on commands received from the scanner base  102 . If power conservation is desired, the scale support unit  112  may supply power to the scale mechanism  110 , or to the amplifier  204  within the scale support unit, only when weight information is desired. In such a case, the scanner base  102  requests a weight reading and the scale support unit  112  powers up any necessary elements. Once the weight reading has been received, the scanner base  102  indicates that the reading is no longer needed, and the scale support unit  112  removes power. The scale support unit  112  may include a processor  208 , which may be a low cost limited function processor having sufficient capability to perform a limited set of operations such as are necessary to respond to queries and commands from the scanner base  102 , to direct operation of the scale mechanism  110 , and to format weight signals as necessary and supply the weight signals to the scanner base  102 . 
   The scale support unit  112  may also suitably include high speed memory  210  and relatively long term storage, here implemented as flash memory  212 . The scale support unit  112  suitably operates under the control of a scale support module  216 , suitably hosted in the flash memory  212  and transferred to high speed memory  210  as needed for execution by the processor  208 . The scale support module  214  may suitably be the only program executed by the processor  208 , and therefore may be transferred to high speed memory  210  at initialization of the scanner  100  and remain there during operation. The scale support module  214  performs all functions needed for managing operation of the scale mechanism  110 , responding to queries and commands from the scanner base  102  and formatting weight readings and supplying the weight readings to the scanner base  102 . 
   The scale support module  214  also manages communication with the scanner base  102  and power to the scanner support unit  112  and scanner mechanism  110 . The scale support module  214  also provides identification information to the scanner base  102 . The scanner top plate assembly  104  may be one of a variety of different types of scanner top plate assemblies that may be used interchangeably with a single scanner base such as the scanner base  102 . At installation or at other suitable times, such as at each initialization of the scanner  100 , the scale support module  214  conveys identification information to the scanner base  102  in order to identify the scanner top plate assembly as belonging to a specified type. The scanner base  102  then configures its operation so as to communicate properly with the particular type of scanner top plate assembly that is installed. Further details of this configuration, and choices that may be made in configuration, are discussed in greater detail below. 
   The wired connection for power through the rest point  114 A of the top plate assembly  104  and the support point  116 A of the scanner base  102 , and for communication through the rest point  114 D of the top plate assembly  104  and the support point  116 D of the scanner base  102 , as illustrated in  FIG. 1A  and  FIG. 2A , is capable of providing necessary power to the elements in the top plate assembly  104  without a need for a cable connection to the top plate assembly  104 . Use of a cable connection to the top plate assembly  104  would call for considerable caution in order to prevent unpredictable influences of the weight of any cabling on weight readings generated by the scale mechanism. Supplying power and communication through the illustrated contact avoids introducing any unpredictable weight influences. 
     FIG. 2B  is a diagram of the scanner top plate assembly  142  of  FIG. 1B , showing the various elements of the scanner top plate assembly  142  in block form. The scale mechanism  110 , the scale support unit  112 , the rest points  114 A- 114 D and the various elements  202 - 214  are shown here. In addition, the battery  144  and the wireless communication unit  146  are shown. The battery  144  and the wireless communication unit  146  provide power and communication through stable mechanisms, free of unpredictable weight influences. The wireless communication unit  146  receives commands and queries from the scanner base  102  and conveys the commands and queries to the scale support unit  112 . In turn, the wireless communication unit receives responses and weight readings from the scale support unit  112  and transmits the responses and weight readings to the scanner base  102 , in communication with the wireless scale communication interface  130  of the scanner base  102 . 
     FIG. 2C  is a diagram of the scanner top plate assembly  152  of  FIG. 1C , showing the various elements of the scanner top plate assembly  152  in block form. The scale mechanism  110 , the scale support unit  112 , the rest points  114 A- 114 D and the various elements  202 - 214  are shown here. In addition, the solar cell  154  and the wireless communication unit  156  are shown. 
     FIG. 2D  is a diagram of the scanner top plate assembly  162  of  FIG. 1D , showing the various elements of the scanner top plate assembly  162  in block form. The scale mechanism  110 , the scale support unit  112 , the rest points  114 A- 114 D and the various elements  202 - 214  are shown here. In addition, the inductive coupling unit  164  is shown. As discussed above, the inductive coupling unit supplies power and communication through an inductive link with a mating element in the scanner base  102 . 
     FIG. 3  is a diagram of the scanner base  102 , showing various elements of the scanner base  102  in block form. The scanner base  102  includes the top plate assembly control and communication interface  118 , the wireless power transmission interface  128  and the wireless scale communication interface  130 . The top plate assembly control and communication interface  118  includes a processor  302 , high speed memory  304  and relatively long term storage such as a flash memory  306 . The top plate assembly control and communication interface  118  operates under the control of a top plate assembly control and communication module  308 , suitably implemented as software stored in the flash memory  306  and transferred to high speed memory  304  for execution by the processor  302  when needed. The top plate assembly control and communication interface  118  is shown here as comprising elements independent from elements performing other data processing, such as the bar code processing unit  120  and the terminal communication unit  122 , but it will be recognized that the top plate assembly control and communication interface  118  need not be a distinct element and that its functions may be performed as a subset of the functions performed by other elements of the scanner base  102 . 
   The top plate assembly control and communication interface  118  is able to communicate with a scanner top plate assembly such as the scanner top plate assembly  104  through a wired connection to the support point  116 D, which makes contact with the rest point  114 D of the top plate assembly  104 . Additionally or as an alternative, the top plate assembly control and communication interface  118  is able to communicate through the wireless scale communication interface  130 . In order to accommodate various different types of top plate assemblies, the wireless scale communication interface  130  suitably includes an infrared interface  310 , a radiofrequency interface  312 , a reflected backscatter interface  314  and an optical interface  316 . As noted above, the scanner base  102  also includes the wireless power transmission interface  128 , suitably implemented as an inductive coupling  318  mating with a similar coupling in the top plate assembly  104 , when such a coupling is used to implement the power element  216  of the top plate assembly  104 . If the power element  216  is implemented as a suitably designed inductive coupling, the wireless power transmission interface  128  may be used to carry out communication through magnetic induction. The scanner base  102  also includes a light source, such as the light emitting diode (LED)  132 , used to provide light to a top plate assembly whose scale mechanism and support electronics are powered by a solar cell. 
   A scanner top plate assembly such as the top plate assembly  104  is mated to the scanner base  102  by placing the top plate assembly  104  on the base  102 , suitably aligning the rest points  114 A- 114 D with the support points  116 A- 116 D, and making any additional attachments needed to secure and stabilize the fixture of the top plate assembly  104  onto the base  104 . For example, the rest points  114 A- 114 D and the support points  116 A- 116 D may be designed so as to be secured with clamps or screws. Once the connection is made, the scanner base  102  may be initialized and establish communication with the top plate assembly  104 . Such establishment of communication may be accomplished by interrogation by the top plate assembly control and communication module  308  of each of the interfaces  310 ,  312 ,  314  and  316 , the wireless power interface  128 , and the connection provided by the contact between the rest point  114 D and the support point  116 D, in order to detect a top plate assembly identification signal. Once an identification signal has been detected, the top plate assembly control and communication module  308  may select the appropriate interface or connection for communication and may deactivate, or simply ignore signals from, the other interfaces. 
   A plurality of interfaces  310 ,  312  and  314  and  316  are shown here as being simultaneously deployed and automatically selected for use. However, it will be recognized that a scanner base such as the scanner base  102  may be designed with only one type of interface. It will also be recognized that in cases of multiple possible interfaces, selection need not be made by querying the different interfaces for an identification signal, but instead may be made in any of a variety of other ways. For example, initialization software may be run on a terminal connected to the scanner  100  whenever a top plate assembly is installed or changed, with the installation software allowing specification of the top plate assembly being installed. 
   It will also be recognized that the scanner base  102  may accommodate a top plate assembly with no scale mechanism. In many scanner installations, all goods are individually priced and will not be sold by weight. In such cases, a user does not need to pay for a scanner with scale capabilities. In such installations, a scanner without scale capabilities may be furnished simply by providing a scanner base such as the scanner base  102  together with a top plate assembly with no scale mechanism or accompanying electronics. If a scanner base such as the scanner base  102  is used, having various elements to accommodate and communicate with a scale mechanism, the top plate assembly control and communication module  308  may take appropriate action upon failure to receive an identification signal upon response to a query. Such action may include, for example, presenting a query to an operator for display by a terminal connected to the scanner  100 , requesting confirmation that the installed top plate assembly has no scale capabilities. It will also be recognized that a scanner base similar to the scanner base  102  may be furnished, but without the hardware needed to accommodate and communicate with a scale mechanism. The scanner base  102  may be designed such that the elements such as the top plate assembly control and communication interface  118 , the power transmission interface  128  and the wireless communication interface  130  are removable modular elements, so that a scanner base may be supplied without these elements to save costs if they are not needed. 
     FIG. 4  illustrates a process  400  of scanner installation and use according to an aspect of the present invention. At step  402 , a scanner base is installed. The scanner base is suitably similar to the base  102  of  FIGS. 1 and 3 . At step  404 , a scanner top plate assembly is mated to the scanner base. The scanner top plate assembly may be similar to the top plate assembly  104  of  FIGS. 1 and 2 , including a scale mechanism, but may alternatively be a simple plate with a scan window, lacking a scale mechanism. At step  406 , the scanner base and top plate assembly are initialized, with the type of scanner top plate assembly being automatically or manually identified to the scanner base. At step  408 , if the scanner top plate assembly includes a scale mechanism, communication between the scanner base and the scanner top plate assembly is initialized so as to permit the scanner base to receive and interpret weight readings from the scanner top plate assembly. At step  410 , the scanner base and scanner top plate assembly are operated as needed to provide data for use in transactions as needed, with operational choices being made based in part of the type of top plate assembly identified on initialization. For example, depending on the type of top plate assembly identified, communication may be performed through a wired connection or through an appropriate wireless interface compatible with a wireless interface used by the top plate assembly. 
   While the present invention is disclosed in the context of a presently preferred embodiment, it will be recognized that a wide variety of implementations may be employed by persons of ordinary skill in the art consistent with the above discussion and the claims which follow below.