Patent Publication Number: US-7712669-B2

Title: Hand-held data capture system with interchangeable modules

Description:
REFERENCE TO RELATED APPLICATIONS 
     Cross-reference is made to the following related patent applications: 
     (1) The present application is a continuation of U.S. Ser. No. 08/478,488, filed Jun. 7, 1995, which is a continuation of U.S. Ser. No. 08/360,014, entitled “Hand-Held Data Capture System With Interchangeable Modules,” filed Dec. 20, 1994 in the names of Koenck et al., which is a continuation of U.S. Ser. No. 07/777,393, entitled “Hand-Held Data Capture System With Interchangeable Modes,” filed Jan. 7, 1992 in the names of Koenck et al., now U.S. Pat. No. 5,410,141, which is the U.S.A. national phase of International Application No. PCT/US/90/03282, entitled “Hand-Held Data Capture System With Interchangeable Modules” with an International Filing Date of Jun. 7, 1990 in the names of Steven B. Koenck et al. 
     (2) The present application is also a continuation-in-part of U.S. application Ser. No. 08/040,313, entitled “Pocket Size Data Capture Unit With Processor and Shell Modules”, filed Mar. 29, 1993 now U.S. Pat. No. 6,468,947. 
     (3) U.S. application Ser. No. 07/707,954, entitled “Hand-Held Computerized Data Collection Terminal with Rechargeable Battery Pack Sensor and Battery Power Conservation”, filed May 22, 1991 in the names of Keith K. Cargin et al., now abandoned. 
     (4) U.S. application Ser. No. 07/339,330, entitled “Hand-Held Computer Terminal” filed Apr. 14, 1989 in the names of Keith K. Cargin et al., now abandoned. 
     (5) Ser. No. 06/897,547, entitled “Core Computer Processor Module, and Peripheral Shell Module Assembled to Form a Pocket Size Data Capture Unit” in the names of Dennis A. Durbin, Stephen J. Kelley, et al. filed Aug. 15, 1986, now abandoned. 
     (6) U.S. Ser. No. 07/744,813, entitled “Modular Hand-Held System Capable of Bar code Scanning And On-line RF Transmission of Scanning Data”, filed Aug. 12, 1991 in the names of Arvin D. Danielson and Darald R. Schultz, now abandoned. 
     (7) U.S. Ser. No. 07/364,902, entitled, “Modular Hand-Held System Capable of Bar Code Scanning and On-Line RF Transmission of Scanning Data”, filed Jun. 8, 1989 in the names of Arvin D. Danielson, and Darald R. Schultz, now abandoned. 
     (8) U.S. Ser. No. 07/364,594, entitled “Hand-Held Computer Terminal” filed Jun. 7, 1989 in the names of Keith K. Cargin et al., now abandoned. 
     (9) U.S. application Ser. No. 07/451,322, entitled “Core Computer Processor Module, and Peripheral Shell Module Assembled to Form a Pocket Size Data Capture Unit” filed Dec. 15, 1989 in the names of Arvin A. Danielson and Dennis A. Durbin, now U.S. Pat. No. 5,227,614. 
     (10) U.S. application Ser. No. 07/143,921, entitled “Core Computer Processor Module, and Peripheral Shell Module Assembled to Form a Pocket Size Data Capture Unit” filed Jan. 14, 1988 in the names of Arvin A. Danielson and Dennis A. Durbin, now abandoned. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention generally relates to data collection systems wherein a hand-held unit is operated from battery power and functions to collect and process data by a sequence of automated and manual operations. A typical automated process is the non-contact scanning of bar code data by means of a cyclically deflected laser beam or with the use of an image photosensor of the CCD type. Once a valid bar code reading has been obtained, a keyboard may be manually operated to indicate an associated quantity. The user may then manually initiate a further operation, for example, the on-line transmission of the data to a remote host computer e.g. via a radio frequency communications link. 
     The presently known data capture devices which include a user interface such as a keyboard and display, and a non-contact automatic reader function have tended to be highly specialized, bulky and expensive. In a prior art device having the desired functions, it may be necessary to completely invert the device after a bar code reading, in order to view the display, and/or to actuate the keyboard. 
     Devices which essentially add a keyboard and display to an existing scanner design may be particularly awkward to use, for example because the keyboard and display are applied at the forward end of the scanner where they are not conveniently accessible and where manual forces applied to the keyboard are tedious to counteract with the supporting handle which is much closer to the user&#39;s body. 
     It would be desirable to have a basic data capture terminal which is light weight and compact, and which could be readily converted for on-line wireless communications and bar code scanning as needed. Such a versatile data capture system would be particularly suitable for small scale operations where low cost is a major objective, and versatility of the terminal unit is especially advantageous. Furthermore, in order to realize the benefits of mass production, it is desirable from the manufacturer&#39;s standpoint if a basic computerized terminal configuration can be readily adapted to the needs of diverse end users by the selective addition of low cost modules. 
     SUMMARY OF THE INVENTION 
     In accordance with an important aspect of the present invention, a light weight low cost basic terminal can be adapted for on-line RF communication with a host computer and selectively accommodate high throughput bar code scanners of the instant type such as CCD bar code scanners and deflected laser beam scanners, while essentially avoiding the deficiencies in the prior art devices. 
     It is highly desirable that the data capture system be compatible with existing peripheral equipment e.g. for downloading data to the terminal and where applicable recharging the terminal batteries. In a particularly advantageous embodiment a basic terminal unit has one end with external contacts compatible with existing communicating and recharging docking apparatus and an opposite end adapted to selectively receive various modular adaptor end caps. Besides a compatibility end cap providing standard overall dimensions and a standard electrical connector arrangement compatible with an existing printer docking receptacle, the terminal may be coupled with an automatic bar code scanner or other desired peripheral device. Thug basic terminal may receive an RF module adapting the terminal for on-line RF communications. 
     In accordance with preferred features, the RF module can be removed and replaced with another similar module without requiring any tuning adjustments. Further such module interchange can most preferably be carried out in the field by the end user. Because of such capability the useful life of the basic terminal may be extended without service interruptions for return to the factory or service center, and the terminal is readily upgraded and adapted to new operating requirements. For example different operating frequencies can be selected simply by replacing the RF module. This is achieved by stocking only the desired modules which are of low cost in comparison to the total system. Similarly, the laser scanning component may be associated with the basic terminal only as needed, the basic terminal alone being used where only this type of capability is required. 
     An object of the invention is to provide a basic terminal configuration of compact light weight construction but which is readily adapted to wireless data communication with other components of a data capture system such as a host computer, and which preferably retains a capability for coupling with a non-contact self scanning type bar code reader or other highly efficient data capture component. 
     Another object is to provide such a basic terminal configuration which can be quickly and easily associated with a wireless transceiver module without requiring special tools. 
     A further object of the invention resides in the provision of a basic terminal configuration with modular means for providing RF communications capability or the like. Preferably the RF module can be replaced in the field without requiring any tuning adjustment. 
     Still another object of the invention relates to the provision of a hand-held type data capture system wherein a basic low cost light weight terminal unit can selectively receive various modules such as an RF module, but such system retaining the option of compatibility with existing communicating and/or recharging docking receptacles (e.g. of a portable printer or the like). 
     In an illustrated embodiment, an RF adaptor module is electrically coupled with a control microprocessor of the basic terminal configuration. The control microprocessor may be installed on a peripheral card within the terminal, and the peripheral card in turn may have pin and socket type coupling with a host printed circuit hoard mounting a main computer processor. The RF adaptor module may have a standard external connector fitting and may contain electrical connector means therefor which automatically engage with mating electrical connector means on the peripheral card as the end cap module is mechanically applied to the terminal. Radio frequency and/or scanner cabling from the peripheral card may pass through a slot in the end wall of the terminal and may be manually connected with the receive/transmit circuits and/or external scanner connector of the RF module prior to fastening of the module to the terminal, or automatic coupling means may be provided for the RF and/or scanner circuits as well as for the standard external connector fitting. 
     In a further advantageous development, a basic terminal part is essentially of length to fit along the palm of the user&#39;s hand. A wireless communications module may be arranged in line with the basic part to form therewith a terminal module. A user interface module may overlie the terminal module and may have its undersurface mating with the terminal module. The terminal module may have a standard width so as to be comfortably embraced by the user&#39;s hand, while user interface modules of different widths may be applied thereto so that different widths of keyboard and display are readily available. Preferably a keyboard directly overlies the hand grip of the basic terminal part. Different user interface modules may provide different key arrangements and keys with greater spacing for example. 
     A docking unit may be configured to receive the basic terminal part while accommodating any of the various width interface modules. Advantageously the basic terminal part may have longitudinal grooves which interfit with guide ribs of the docking unit as the terminal is inserted. The grooves may facilitate secure manual gripping of the terminal during use. 
     The mating parts of the terminal are modular in the sense that they can be readily disconnected from each other. One interface part can be disconnected, removed as a unit, and replaced with a part of the same or different width. Similarly, the basic part or wireless part is readily disconnected from the other parts, removed as a unit, and replaced. Further in preferred form each modular part has only quick disconnect type signal coupling with the other parts, and most preferably the parts are self-guided so that the couplings are achieved as the automatic result of correct interfitting of the parts, as the parts are pressed together. In the ideal embodiment, each module has definable performance characteristics which permit it to be tested and adjusted as a separate unit. Then the various parts can be interchanged without requiring any further tuning or adjustment. 
     In a still further highly advantageous development, an entire terminal is of optimum size and weight so as to be comfortably contained in the hand during use. As before, the terminal is modular particularly so as to selectively receive a wireless communication module or a combined wireless communication and automatic reader module. The basic terminal parts may comprise a user interface top layer and a battery containing layer underlying approximately one half of the interface layer. The communication module or the combined communication and reader module may be selectively interfitted with the basic terminal parts to form a highly compact terminal which is particularly comfortably gripped. 
     Other objects, features and advantages will be apparent from the following detailed description, taken in connection with the accompanying drawings, and from the individual features and relationships of the respective appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a somewhat diagrammatic frontal perspective view showing a hand-held data capture terminal which may be modified as shown in  FIGS. 6-10  and  FIGS. 11-19 , to form embodiments of the present invention. 
         FIG. 2  is a somewhat diagrammatic exploded view of the hand-held terminal illustrated in  FIG. 1 . 
         FIGS. 3 and 4  are schematic diagrams showing the major electronic circuits and components contained within the terminal of  FIGS. 1 and 2  and the interconnections between them,  FIG. 4  showing preferred circuit details for the power control components of  FIG. 3 . 
         FIG. 5  is a plan view showing the interior of the end cap of the terminal shown in  FIGS. 1-4 . 
         FIG. 6  is a perspective view of an embodiment including the basic terminal of  FIGS. 1-5  and further including provision for on-line radio frequency communications capability. 
         FIG. 7  is an exploded perspective view of the modular adaptor end cap of the embodiment of  FIG. 6 . 
         FIG. 8  is an exploded perspective view of the embodiment of  FIG. 6 . 
         FIG. 9  is a block schematic diagram showing the electronic system components of the embodiment of  FIG. 6 . 
         FIG. 10  is a block schematic diagram similar to  FIG. 9 , but showing an improved circuit arrangement for facilitating interchangeability of the RF end cap module and in particular avoiding the need for any tuning adjustments when an RF end cap module is applied to the basic terminal in the field. 
         FIG. 11  is a somewhat diagrammatic perspective view showing a modular hand-held data capture device in accordance with the present invention. 
         FIG. 12  is a side elevational view showing a RF data terminal in solid lines, and indicating with dash lines a scanner module which is mated therewith, to form the unitary hand-held data capture device of  FIG. 11 . 
         FIG. 13  is a top plan view of the scanner module which forms part of the data capture device of  FIG. 11 . 
         FIG. 14  is a side elevational view of the scanner module of  FIG. 13 , showing the handle detached but in vertical alignment with its attachment position, and showing locating studs on the handle which fit into the scanner body during assembly % herewith. 
         FIG. 15  is a bottom plan view of the scanner body, showing the sealed slots which serve to locate a handle therewith. 
         FIG. 16  is a front end elevational view of the data capture device of  FIG. 11 . 
         FIG. 17  is a rear end elevational view of the data capture device of  FIG. 11 . 
         FIG. 18  is a somewhat diagrammatic side elevational view, similar to  FIG. 12 , but illustrating with dash lines a modification wherein the scanner module is provided with contacts at a rear end thereof for engagement with the external set of contacts of the terminal unit. 
         FIG. 19  is a diagrammatic view indicating an exemplary lay-out of parts within the scanner module of  FIGS. 11-17  or  FIG. 18 . 
         FIGS. 20 ,  21  and  22  are somewhat diagrammatic plan, side elevational and end views showing a modular data capture system wherein the user interface module and the peripheral modules are readily removed and replaced with modules of the same or different characteristics. 
         FIGS. 23 ,  24  and  25  are somewhat diagrammatic plan, side and end views wherein the user interface module of  FIGS. 20-22  has been replaced by a much wider version, also illustrating the case where a peripheral module may provide a forwardly directed automatic reader as well as an RF communications link. 
         FIGS. 26 ,  27  and  28  are somewhat diagrammatic plan, side elevational, and end views wherein the user interface module is of intermediate size and wherein a compact automatic reader scans along a horizontal path when the long axis of the terminal is disposed vertically. 
         FIGS. 29 ,  30  and  31  are somewhat diagrammatic plan, side and end views wherein the terminal corresponds with that of  FIGS. 20-22  except that a peripheral module is designed to accommodate a conventional rotary prism laser scanner. 
         FIGS. 32-35  are side elevational, plan and opposite end views of a further modular terminal configuration in accordance with the present invention. 
         FIGS. 36 and 37  are side and end views showing the basic user interface and battery/control modules of  FIGS. 32-35 , but with the radio frequency communications/scanner module of  FIGS. 32-35  replaced by an RF communications module. 
     
    
    
     MODES FOR CARRYING OUT THE INVENTION 
     Detailed Description of FIGS.  1 - 10   
       FIG. 1  shows a portable hand-held data capture terminal  10  embodying aspects of the present invention. The terminal  10  has an elongated housing formed of parts  11  and  12 , the back housing part  12  of which is formed in a manner so as to enable a user to hold the device comfortably in one hand for extended periods of time. 
     In the preferred embodiment of the invention, terminal  10  may be powered by a rechargeable nickel-cadmium battery pack  20  ( FIG. 2 ) or a plurality of AA size batteries. Enclosed within the terminal housing  11 ,  12  are four permanently mounted printed circuit boards  26 ,  37 ,  41 , and  43 , ( FIG. 2 ), namely a host printed circuit board  37 , a display printed circuit board  43 , a keypad printed circuit board  41 , and a peripheral controller printed circuit board  26 . Interconnections between the circuit boards are accomplished through a plurality of pin and socket type connectors including pin type connectors  86  and mating receptacle type connectors  87 . An exception is the interconnection between display board  43  and keypad board  41  which is accomplished through a resilient conductive pad  42 . When assembled, front housing part  11  and back housing part  12  are joined together by a plurality of screws  88 . 
     The front housing part  11  of the terminal  10  provides a mounting platform for a display  13  ( FIG. 2 ) which may provide a visual indication of various types of information. In the preferred embodiment of the invention, display  13  is of a liquid crystal display (LCD) variety providing sixteen lines, with twenty characters per line, of display area. Optionally, the display  13  may be of a four line type. The display  13  may be mounted upon a display printed circuit board  43  which is then mounted or secured to front housing part  11  by a plurality of screws  58 . In addition, the front housing part  11  may provide a mounting platform for a keypad  14  ( FIG. 1 ), having a plurality of keys  56  thereon. In the preferred embodiment of the invention, keypad  14  is provided with either twenty-three or forty keys. The control and interface circuitry for keypad  14  may be contained on keypad printed circuit board  41  ( FIG. 2 ) which is mounted or secured to front housing part  11  by a plurality of screws  59 . 
     Electrical interconnections between the display printed circuit board  43  and keypad printed circuit board  41  may be accomplished through a resilient, conductive pad  42 , which may be located between overlapping portions of the aforementioned circuit boards and retained in this location by means of the pressure exerted upon it when the respective circuit boards are mounted in the housing part  11 . Conductive pad  42  may contain a plurality of generally parallel, spaced apart conductive elements embedded within it. The overlapping portions of display printed circuit board  43  and keypad printed circuit board  41  each contain a plurality of coplanar, generally parallel, and evenly spaced apart connector elements  60  and  61 , respectively. The respective conductive elements of conductive pad  42 , when conductive pad  42  is mounted between the overlapping portions of keypad printed circuit board  41  and display printed circuit board  43 , are in positive contact with corresponding aligned connector elements  60  and  61 , and provide respective paths for the transfer of electrical signals therebetween. Alternatively, the required electrical interconnections between display printed circuit board  43  and keypad printed circuit board  41  may be accomplished through a flexible multi-conductor ribbon type cable. 
     The back housing part  12  of the terminal  10  may provide a mounting platform for a removable, elastic type flexible strap  15  ( FIG. 2 ). Flexible strap  15  may allow the user of the terminal  10  to relax the user&#39;s grip on the terminal  10  for short periods of time, without actually removing the terminal  10  from the user&#39;s hand. The flexible strap  15  may be secured to the bottom of housing part  12  by means of two retaining clamps such as  16  ( FIG. 2 ). Retaining clamps  16  are secured to housing part  12  through the use of screws such as  57 , with two screws  57  securing each retaining clamp. In the preferred embodiment of the invention, retaining clamps  16  may be removed with simple hand tools, allowing the flexible strap  15  to be easily replaced. Beneath the flexible strap  15  and generally between retaining clamps  16 , the bottom of housing part  12  is contoured in such a way that, when the terminal  10  is being held by the user, the user&#39;s hand is placed on a recessed area  62  ( FIG. 1 ) in housing part  12  and beneath flexible strap  15 . 
     Referring to  FIG. 2 , the top end of the terminal  10  may be enclosed with a removable end cap  18 . End cap  18  is attached with two screws  64  to housing part  12 . When installed on terminal  10 , end cap  18  overlies and encloses opening  65  and cavity  63 . Located on, and part of the end cap  18  may be a multiple pin D-sub type connector  19 , which may in turn be direct or hard wired via a flexible multi-conductor ribbon type cable  20  to a connector platform  21 , on which may be mounted two connector receptacles  22  and  23 . Cable  20 , connector platform  21  and connector receptacles  22  and  23  may also be mounted on and be part of end cap  18 . Screws such as  24 ,  FIG. 2 , may secure parts  21 ,  22 ,  23  in a precise location with only connectors  22 ,  23  projecting beyond the confines of the end cap housing. The multiple pin D-sub connector  19  may provide a communications port capable of the two-way transfer of data with other compatible devices according to the RS-232C standard as defined by the Electronic Industries Association. When end cap  18  is installed on terminal  10 , receptacles  22  and  23  automatically mate with a plurality of pins  67  and  68  which protrude through connector blocks  69  and  70 . Pins  67  and  68 , and connector blocks  69  and  70  are each attached or connected to peripheral controller board  26 . In a preferred embodiment of the invention, the end cap  18  may be removable using common hand tools. Alternatively, a plain type of end cap housing which does not contain a D-sub connector  19  or any of its associated components such as  20 - 23 , may be used in place of end cap  18 . In addition, peripheral controller board  26  provides the electronic circuitry required to interface the two-way data transfer which may occur through D-sub connector  19 . In a preferred embodiment, controller board  26  may be a peripheral type device which may be exchanged or otherwise configured to enable the use of various types of end cap devices. These various end cap devices may enable terminal  10  to perform a wide variety of functions not currently possible with existing hand held data capture devices including, but in no way limited to, the two-way transfer of data through space using radio frequency waves as the data carrying medium, the two-way transfer of data over telephonic communication links, and the two-way transfer of data between the terminal and a bar code reading device. 
     Referring again to  FIG. 2 , the cavity of the housing part  12  receiving the battery pack  28  may be enclosed by a battery compartment hatch  27 . The battery compartment hatch  27  may have attached to its surface a plurality of conductive metallic type contacts  30 . Metallic contacts  30 , in conjunction with a plurality of metallic springs located in the battery compartment, may complete the electrical path of the batteries enclosed in the battery compartment. When the battery compartment hatch  27  is properly installed on the terminal  10 , it comes in contact with a conductive metallic rod which extends the length of the battery compartment and is hard wired to battery supply connector  71 ,  FIG. 2 , and completes the ground or negative potential path for the batteries. The enclosed batteries are arranged in the battery compartment in a series type configuration to provide the required voltage. The positive potential of the battery path is completed by the hard wiring of a metallic spring to battery supply connector  71 . Battery supply connector  71  contains a plurality of receptacles which mate with host hoard  37  to provide the battery power to the terminal  10 . Battery compartment hatch  27  attaches to the bottom housing part  12  of terminal  10  through the interlocking and meshing of railings on both the battery compartment hatch  27  and bottom housing part  12 . The battery compartment is formed by a cavity within terminal  10 , with a somewhat rectangular opening on which three corners are rounded and one corner is somewhat squared. 
     Battery pack  28  may be constructed of a plurality of nickel-cadmium battery cells, arranged in such a way as to provide approximately six volts of direct current electrical power. In addition, battery pack  28  may contain a formed metallic plate  31  which may be attached to the nickel-cadmium batteries in such a way as to form a somewhat squared edge on one corner  86  of the battery pack  28 . The somewhat squared corner  86  ( FIG. 2 ) of the battery pack  28  may correspond with the previously described somewhat squared corner on the rectangular opening of the battery compartment, and may prevent the improper insertion of battery pack  28  into the battery compartment. In addition, metallic plate  31  may be further formed to create a conductive metallic shunt  32  ( FIG. 2 ). When battery pack  28  is installed in computer terminal  10 , metallic shunt  32  engages probes to create an electrically conductive path or short circuit between the probes. The probes may form part of the battery charging circuit of the terminal  10  and may disable this circuit when not electrically shorted together, thereby preventing the inadvertent and possibly hazardous application of recharging electrical power to non-rechargeable (e.g. alkaline) batteries. 
     In place of the battery arrangement  28 , the batteries can be mounted in an enclosed drawer part with square and rounded edges, which slides endwise into a receiving compartment. External contacts on the drawer may be substituted for the array of external contacts as shown at  322 ,  FIG. 11 . The rear external contacts at the drawer external wall may be connected with respective spring contacts at the forward end of the drawer which spring contacts engage with fixed contacts in the roof of the battery compartment as the drawer is fully inserted. A coin operated latch may be rotatable through a given angular amount in one direction to lock the battery drawer in place, and may be rotatable in the opposite direction to unlock the battery drawer. 
     Description of  FIG. 3   
     Referring now to  FIG. 3 , the terminal functional block diagram is illustrated. A central processor unit (CPU)  74  may contain program storage and reside on the host printed circuit board. CPU  74  controls all terminal functions, executes machine instructions in proper sequence, and supervises data communication with devices inside and outside the terminal  10 . However, it may allow an optional auxiliary processor unit on the peripheral controller board  26  to control some external access (e.g. reading from and/or writing to an auxiliary memory card). The CPU  74  may abort all communications throughout terminal  10  should power available from the main batteries (e.g. nickel-cadmium battery pack  28 ) drop below a predetermined level. All access to static RAM  75 , the real time clock  76 , the keypad  14  and keypad circuit board  41 , and display  13  and display circuit board  43  are accomplished through CPU  74 . The CPU  74  also controls the charging current applied to battery pack  28  by control of CHGON line  46 ,  FIG. 4 , and generates a signal on MEMON line  50  to initiate a sleep mode of the terminal. In addition, CPU  74  allows activation of the 485 circuit and watchdog timer component  77 , RS232 level converter  78 , and the backlight of display  13 . 
     The memory in static RAM  75  is decoded in the decode circuit  79 . MEMDIS line  83  is coupled with this circuit and will inhibit access to static RAM  75  in the event the five volt regulator  80  has dropped out of regulation, indicating the installed batteries (e.g. nickel-cadmium battery pack  28 ) are no longer providing the necessary voltage. In the preferred embodiment of the invention, memory in the static RAM  75  may be selectively configured in one of varying sizes. 
     The terminal  10  may be equipped with a battery/charge monitor circuit  81  as well as a battery charge circuit  82 . The battery/charge monitor circuit  81  monitors the main battery and provides a signal on the LOWBATT line if battery voltage drops below a certain value. The signal on the LOWBATT line informs the CPU  74  that battery flower is getting low, and CPU  74  in turn will notify the user through the display  13 . The terminal  10  will continue to operate normally as long as the LOWBATT line remains in a high logical state. If the LOWBATT line goes low, the terminal  10  will switch to its inactive (sleep) state, but will be allowed to become active if a key  56  ( FIG. 1 ) is pressed. A further output of the monitor component  81  is the DDEC line. The DDEC line provides a true indication if the five volt regulator  80  begins to drop out of regulation. When the DDEC line goes low, the terminal  10  switches to sleep mode promptly, saving all data in the static RAM  75 , which will have backup power in the event that the main batteries are removed. Finally, when tire output of the main batteries (through five volt regulator  80 ) drops to a predefined level, the MEMDIS line  83  will carry a low logical signal, causing the static RAM  75  to be disabled, the CPU  74  to be reset and the transistor  54  ( FIG. 4 ), located in the power isolation circuit  84 , to switch to nonconducting mode. The CPU  74  is equipped with an analog input port which allows it to monitor several other battery/charge conditions. The signals available at this port may provide information regarding the charge level, for example. Another signal which may be monitored here is an extended duration signal emanating from the KEYINT line  85 . The controller board  26  may also provide an interrupt signal on PERINT line  86 , which is made available to the CPU  74  on this analog port. 
     The charge circuit  82  is disabled unless a shorting mechanism (conductive metallic plate  32 ,  FIGS. 2 and 4 ) which is located on and part of the nickel-cadmium battery pack  28 , is present and properly installed in the battery compartment as described previously. Charging of an installed nickel-cadmium battery pack  28  occurs automatically when a charge voltage of a predetermined value is present on CHARGE line  87 . Charging of the installed nickel-cadmium battery pack on may occult selectively at a rate of approximately twenty milliamps or a rate of approximately seventy-five milliamps, and is determined by the terminal software through CPU  74 . The CPU  74  also monitors the ambient air temperature and, if below a predetermined level; preferably approximately five degrees Celsius, the CPU  74  causes the LOWTEMP line  88  to provide a signal, which causes constant current charge to default to the lower charge (twenty milliamps) rate. When terminal  10  is first attached or otherwise connected to a charger, the CHGDET line  89  goes active for approximately four milliseconds, then returns to its inactive state. This causes NMI generator  90  to generate a pulse to wake the terminal  10  from its sleep mode and signal that a charger is present. 
     A charger must be attached to terminal  10  for the 485 circuit and watchdog component  77  to function, as this circuit is powered by the charger. The 485 circuit and watchdog circuitry  77  may provide the terminal  10  with a communications port capable of synchronous two-way data communication with other compatible devices, transferring data at a rate not greater than five hundred thousand bits per second, according to the predominate RS485 standard as defined by the Electronic Industries Association. When CPU  74  detects the presence of a charger, it activates the 485 circuit and watchdog through 485ON line  91 . Data may then be transmitted and received by terminal  10  on RS485 DATA+line  92  and RS485 DATA−line  93 , these lines being connected to a pair of a number of coplanar, generally parallel and evenly spaced conductive metallic pads  322  ( FIG. 11 ). Received data is applied to the CPU  74  from the 485 circuit and watchdog circuit  77  on 485RXD line  95 , while transmitted data is applied to the 485 circuit and watchdog circuit  77 , from CPU  74 , on 485TXD line  96 . 
     Five volt regulator  80  may operate from either the main battery supply or an attached charger. If both are present, the output voltage of the charger will e higher than the battery voltage, causing five volt regulator  80  to choose current from the charger supply rather than the batteries. This is accomplished through “OR” wiring of diodes  97  and  98 . 
     Terminal  10  has been designed to be in an inactive state (sleep mode) for the majority of time to conserve battery power. As described previously, NMI line  55  must be pulsed for terminal  10  to wake up and begin program execution. The pulse on NMI line  55  is generated by the NMI generator  90  and may be generated by a pulse on KEYINT line from the keypad  14 , a pulse on RTCINT line from the real time clock  76 , simultaneous pulses on LOWBATT line and DDEC line, a pulse on CHGDET line  89 , a pulse on PERINT line  86  from peripheral controller board  26 , or a pulse on the PWRUP line (from the 5V regulator  80 ). 
     Power is applied to the peripheral controller board  26  under the control of CPU  74 . Once the controller board power is stable and the controller board microprocessor ( 212 ,  FIGS. 9 and 10 ) is stable, the controller board microprocessor begins a hand shaking sequence with CPU  74  to establish a communication link. This link has some software support to monitor data integrity throughout the transfer of data. The controller board  26  is equipped with a pair of analog switches which isolate the data bus on the controller board  26  from the memory data bus on the host printed circuit board  37 . This isolation prevents inadvertent data bus interference during the power up routine of the peripheral controller board microprocessor. 
     Description of  FIG. 4   
     Referring to  FIG. 4 , unique battery charging and terminal sleep mode circuits are illustrated. When terminal  10  is attached or otherwise connected to a compatible recharging device, a charging voltage may be introduced on the CHRGX line ( FIG. 4 ). The charging voltage on CHRGX line  43  may then be applied to a voltage regulating device  44  e.g. type LP 2951 ACM. The regulated charging voltage output of regulating device  44  may be applied to a transistor switch  45  through a resistor R 73 . Transistor switch  45  may be software controlled, and may be activated or turned on when the signal on CHGON line  46  changes its logical state, which may cause field effect transistor  47  to change state which then may cause transistor switch  45  to change state. Transistor switch  45  may provide a constant charging current through a diode CR 3 , to the installed battery pack  28 , for a predetermined length of time. The charging current may be applied to installed battery pack  28  through metallic terminals in the battery compartment shorted by metallic shunt  32  on the battery pack,  FIG. 2 . 
     The sleep mode circuitry of terminal  10  monitors the input activity of the terminal  10  and, when no activity is detected for a predetermined length of time, may cause the terminal  10  to shift to a stand-by or sleep mode to conserve the power supplied by the installed batteries. When in the inactive state, the memory array and real time clock circuits of terminal  10  require less power than when in an active state. In operation, when the terminal  10  has been inactive (e.g. no keys  56  are pressed on keypad  14 ) for a predetermined amount of time, MEMON line  50  may pulse. This pulse may be sensed on the CLK input of flip-flop integrated circuit  51 , which may cause its Q output to switch levels. Resistor R 140  and capacitor C 96  may ensure that no false signals are received by flip-flop  51 . The Q output of flip-flop  51  is designated MEMSW line  52 . The state of MEMSW line  52  may cause field effect transistor  53  to change state. MEMSW line  52  may be filtered by resistor R 88  and capacitor C 93 . When field effect transistor  53  changes states, it greatly reduces the amount of current flowing through the base of transistor  54  by causing resistor R 59  to be placed in series with resistor R 60 . The greatly reduced current flow through the base of transistor  54  allows the regulated supply of the terminal  10 , provided by the power of the installed batteries applied through a voltage regulating device, to provide less current, thus increasing the active life of the installed batteries. 
     When terminal  10  again becomes active (e.g. a key  56  is depressed on keypad  14 ) NMI line  55  may pulse. The pulse on NMI line  55  may be sensed by flip-flop  51 ,  FIG. 4 , at its CLR input, and may then cause the Q output of flip-flop  51  to change state. The state of MEMSW line  52 ,  FIG. 4 , at the Q output of flip-flop  51  may now cause field effect transistor  53  to reset to its former state, returning current flow through the base of transistor  54  to its active level. 
     The terminal  10  may operate exclusively from the power supplied through a regulating device by the installed batteries (e.g. battery pack  28   FIG. 2 ) until the MEMDIS line  83 ,  FIG. 4 , changes state. The MEMDIS line may change state when the installed batteries or attached charger do not provide sufficient voltage to operate the terminal. When the MEMDIS line changes state, it may change the state of field effect transistor Q 15 . The MEMDIS line may be filtered by resistor R 141  and capacitor C 94 . When field effect transistor Q 15  changes state it may cause interruption of current flow through the base of transistor  54 , effectively removing the regulated supply of terminal  10  from the memory array. When this occurs, a standby lithium battery or a charged capacitor may supply the memory array and real time clock circuits until such time that the main power supply is returned to the level required to power the terminal  10 . A charged capacitor may provide short term back-up power for the terminal  10 , with the lithium battery providing power when the stored charge of the capacitor is depleted. The lithium battery may provide long term back-up power. When the main power of terminal  10  is restored to an operational level, the MEMDIS line  83 ,  FIG. 4 , may return to its former state which may restore normal current flow through the base of transistor  54 . 
     Description of  FIG. 5   
       FIG. 5  is a view looking into the interior of end cap  18 . Three screws such as  24  secure the connector platform  21  at the correct position within the end cap  18 . Two guide parts  38  and,  39  are precisely located so as to project into the open end  72  of housing part  11  and interfit with cooperating surfaces at the end  72  so as to insure that the connector receptacles  22 ,  23  are correctly aligned with pins  67 ,  68  as the end cap  10  is applied to the terminal. This type of mechanical guidance could also be provided for the automatic electrical interconnection of all of the various modules herein which are to be mechanically joined with each other. 
     Description of  FIGS. 6 through 10   
     Referring to  FIGS. 6-10 , an embodiment of the invention is disclosed for providing wireless data communication with a remote receiver. In  FIG. 6 , it can be seen that terminal  110  includes the basic housing parts  11  and  12  of  FIGS. 1-5 , and is further provided with a modular adaptor end cap  118 . Antenna  104  and external connector fitting  119  are attached to the end cap  118 . (Corresponding reference numerals have been applied to identical parts in  FIGS. 1-5  and  6 - 10  and such parts need not be further described). Keys  56  are depressed by the user to enter data and to control the functions of terminal  110 , including causing terminal  110  to transmit or receive data by radio transmission means. Display  13  provides visual information concerning RF transmissions received by the terminal. 
     From  FIG. 8 , it can be understood that end cap  118  may be readily removably mounted on housing parts  11  and  12 . External connector fitting  119  provides for interconnection to optional peripheral devices and is electrically connected through wiring  120  to connectors  122  and  123  which are mounted to connector platform  121 . Connectors  122  and  123  engage with the pins of mating connectors  67  and  68  ( FIG. 2 ) of peripheral controller card  26  when end cap  118  applied to housing parts  11  and  12 . 
     Radio module  106  mounts within end cap  118  by suitable mounting means such as indicted by screw  107  ( FIG. 6 ), and is electrically coupled to peripheral controller card  26  by ribbon cable  108 . Ribbon cable  10  is detachably connected to radio module  106  by a connector  109  affixed to the end of cable  108 , and, enters housing part  11  through opening  65  in wall  66 . Ribbon cable  108  connects at  25 ,  FIG. 2 , with the peripheral controller card  26 , and serves to inter-connect radio module  106  and peripheral controller card  26 . Adjusting elements  114  ( FIG. 8 ) are provided on radio module  106  for frequency tuning and signal level adjustment purposes. 
     Referring now to  FIG. 7 , it can be seen that end cap  118  comprises housing members  116  and  117  which may be separated when end cap  118  is removed from housing parts  11  and  12  in order to provide access to adjusting elements  114  of radio module  106 . 
     Referring to the block diagram of  FIG. 9 , it can be appreciated that radio module  106  houses transmitter  202  which is coupled to antenna  104 . Transmitter  202  is coupled to transmit level adjust circuitry  204 . Receiver  206  is coupled to antenna  104  and to receive level adjust circuitry  208 . Dashed line A separates the components located on radio module  106  from components located on peripheral controller card  26 . Control microprocessor  212  communicates with main microprocessor  216 ,  FIG. 3 , of housing part  11  through coupling means  214  which is provided by connectors  86 ,  87 ,  FIG. 2 . Control microprocessor  212  is coupled to transmitter  202  and receiver  206  by coupling means  215  along which are communicated radio control signals. Data to be transmitted is received from processing unit  216 ,  FIG. 3 , and is forwarded by control microprocessor  212  over TX data line  218  to modulation generator and limiter component  220 . Modulation generator and limiter component  220  is coupled to first low pass filter  222 . Data received by antenna  104  is delivered to control microprocessor  212  on RX data line  223  which couples control microprocessor  212  to data recovery element  224  which is coupled to a second low pass filter  226 . Lines  108   a  and  108   b  and also lines  215  are part of ribbon cable  108  and serve to couple the circuitry of peripheral controller card  26  to radio module  106 . 
     External connector fitting  119  is coupled to control microprocessor  212  by scanning interface signal lines  228  associated with connectors  67 ,  68 ,  FIG. 2 , and  122 ,  123 ,  FIG. 8 , and wiring  120 ,  FIG. 8 . 
     Peripheral control adjustment elements  115  are mounted to peripheral controller card  26  such that these adjustment elements  115  are accessible to the user through opening  65 , thereby obviating the necessity of any disassembly of housing parts  11  and  12  in order to effectuate adjustments to the peripheral controller card  26 . 
     In operation, the user may remove modular adaptor end cap  118  from housing parts  11  and  12  when adjustment of radio components is desired. Adjusting elements  114  ( FIG. 8 ) may be accessed by the separation of housing members  116  and  117  ( FIG. 7 ) while radio module  106  continues to be electrically connected with peripheral controller components on card  26  through ribbon cable  108 . In addition, peripheral control adjustment elements  115  ( FIG. 8 ) of peripheral controller card  26  ( FIG. 2 ) may be accessed when end cap  118  is removed from housing parts  11  and  12 . The user may communicate with a remote host computer in “real time” by operation of keyboard  14  which provides signals to main microprocessor  216  ( FIG. 9 ). Main microprocessor  216  processes the signals and communicates them to control microprocessor  212  of peripheral controller card  26 . Control microprocessor  212  and its associated circuitry on peripheral controller card  26  processes the signals to superimpose them upon radio transmission frequencies, and communicates the processed signals to transmitter  202  which is coupled to antenna  104  and which thereby causes their transmission through space from antenna  104  by electromagnetic radiation. A remote host computer responding to terminal  110  transmits radio frequency signals which are received by receiver  206  through antenna  104 . Received signals are processed on peripheral controller card  26  and are provided to control microprocessor  212  which communicates the processed signals to main microprocessor  216 . Microprocessor  216  displays the received information upon display  13  so that it can be observed by the user. 
       FIG. 10  shows a modification of the embodiment of  FIG. 9  which enables the replacement of the RF adaptor module without requiring a tuning adjustment of the module. In this embodiment the control microprocessor  212  is on the peripheral controller card, while components  220 ,  222 ,  224  and  226  are included in the radio module  106 - 1  forming part of the RF modular adaptor end cap  118 - 1 . This results in a digital interface at  250  between the peripheral controller card of the basic terminal and the radio module of the RF adaptor end cap. 
     Since the signals transmitted across the digital interface are at standardized logic levels, there is no need for tuning adjustment of the RF module to adapt it to a particular basic terminal. The lines  215 ,  218  and  223  may form part of a ribbon cable corresponding to cable  108  with a connector corresponding to connector  109  for plug-in coupling with a mating connector of radio module  106 - 1 . Multiconductor line  228  may be implemented via mating connectors such as  67 ,  22  and  68 ,  23  ( FIG. 2 ) as in the previous embodiments. In each embodiment, power from the battery pack  28  may be supplied to the circuitry of the RF end cap under the control of a radio on/off switch  252 , the power supply path  254 ,  FIG. 10 , being comprised by conductors of a ribbon cable such as  108 , for example. The control microprocessor  212  is coupled with switch component  252  as indicated at  256 , so that all power to the RF end cap can be switched on and off as required to minimize battery drain. 
     Since the peripheral circuit means including  212 ,  FIG. 10 , only transmits standardized digital signals and battery power to the modular adaptor end cap, the end cap circuits can be pre-adjusted at the factory and adjustments by the end user in assembling the modular adaptor end cap with the terminal can be avoided. The peripheral circuit board  26  ( FIG. 2 ) and end cap  18  can be replaced by peripheral controller board  126 ,  FIG. 10 , and the end cap  118 - 1  with radio module  106 - 1 , without requiring any other hardware changes in the terminal. Then the end cap with radio module  106 - 1  can be replaced with a new identical end cap as needed without requiring any adjustments in the digital outputs from the peripheral controller board, and without requiring any tuning adjustments of the modular adaptor end cap. 
     To replace the modular adaptor end cap  118 - 1  with the RF module  106 - 1 , the end cap is removed as in  FIG. 8 , and the RF section  106 - 1  separated at connector  109 ,  FIG. 8 . A new end cap is then coupled with ribbon cable  108  by means of connector corresponding to  109 . This completes the new digital signal paths which are as represented at  215   218 ,  223 ,  154 ,  FIG. 10 . 
     Example According to  FIG. 10   
     In an exemplary embodiment according to  FIG. 10 , the basic hand-held terminal configuration formed from housing parts  11  and  12 ,  FIG. 2 , has peripheral adaptor circuit means  126 ,  FIG. 10 , connected therewith via peripheral connector means similar to  108 ,  109  ( FIG. 8 ), accessible at the upper end of the terminal configuration (see  FIG. 8 ). The basic terminal selectively receives a compatibility end cap (e.g.  18 ,  FIG. 2 ) for enclosing the upper end and providing a resultant hand-held terminal of dimensions compatible with an existing terminal receptacle e.g. of a portable printer. In the portable printer the receptacle for the terminal has an electrical connector at one end for mating with connector  19 ,  FIG. 1 , and a spring-urged retainer at an opposite end for retaining the terminal in operative relation to the printer receptacle. 
     Where it is anticipated that the terminal configuration is to be later adapted to provide an RF link to an external transceiver, the basic terminal configuration may be provided with peripheral adapter circuit means such as represented at  126 ,  FIG. 10 . The peripheral input/output means at digital interface  250 ,  FIG. 10 , may be embodied in a cable and connector (such as  108 ,  109 ,  FIG. 8 ) which is passively contained within a compatibility end cap module such as  18 ,  FIG. 1 , but is ready for plug-in connection with RF module  106 - 1 ,  FIG. 10 , of a modular adaptor/end cap  118 - 1 ,  FIG. 10 . 
     Description of  FIGS. 11 through 19   
     In the illustrated embodiment of  FIGS. 11-19 , a unitary hand-held data capture device  310  comprises housing parts  11  and  12  forming a data terminal body  311 , a RF module  312  (corresponding to module  118 ,  FIG. 9 , or  118 - 1 ,  FIG. 10 ), a scanner module body  313  and a handle  314 . The data terminal formed by components  311  and  312  has a frontal face  316  with user-device input and/or output interface means such as a manual data entry keyboard  14  and a display means at  13 . The frontal face may have an indentation pattern at  320  for assisting in the aiming of the device in relation to a data source such as a bar code label on a product container or the like. 
     In a preferred construction, the terminal body  311  has a set of external contacts  322  for coupling of power and data signals of various types. The RF module  312  may include a stub antenna  104  projecting in a longitudinal direction, and the scanner body  313  may include a scanner extension part  326  which serves to direct scanner energy (e.g. optical energy) obliquely to the general plane of the frontal operating panel  316 . This serves to insure that under normal scanning conditions, the frontal panel  316  will be facing the user during scanning operation so that for example, the user can verify the scanner data as it appears on the display  13 . 
       FIG. 12  shows the device  310  as having a rubber bumper  331 ,  332  extending about the exterior sides of the terminal body  311  and the RF module  312  to protect the device  310  against lateral impact. 
     A connector  334  corresponding to connector  119 , FIG. B, e.g. a standard 15-pin D subminiature connector, may face longitudinally in a forward direction from a section  335  of the RF module  312 . The connector  334  may correspond in its pin assignments with the connector commonly present on RF terminals such as the model 2210 RF terminal of Norand Corporation, Cedar Rapids, Iowa. The connector has pins assigned to the transmission of scanner signals, RS-232 signals, charge potential, and power out, for example. In the illustrated embodiment, the terminal body  311  may contain rechargeable batteries in a battery compartment at section  337 , and battery power may be supplied from the batteries to the RF module by a direct connection and via connector  334  to the scanner module. 
     As shown in  FIG. 13 , the scanner module body  313  is provided with a connector  340  which is mated with terminal connector  334  during the assembly of the terminal parts  311  and  312  with the scanner module. A forward recess  343  of the scanner module body  313  receives terminal housing sections  335 ,  330 , while a rearward recess  344  accommodates a transverse rib  345 ,  FIG. 12 , on the terminal body  311 . The scanner module may have six alignment holes  351 - 356 , and four screw holes  357 - 360  for use in securing the terminal body  311  therewith. 
       FIG. 14  shows locating lugs  361 ,  362  on the handle  314  which interfit with sealed slots  371 - 374 ,  FIG. 15 , at the undersurface  375  of the scanner module  313 . Four contacts  300  on the handle  314  mate with respective cooperating contacts  381 - 304  at undersurface  375 , so that for example the handle  314  may optionally contain batteries and supply battery power to scanner module  313 . The handle is secured to the terminal by means of an integral internally threaded nut  385  at the undersurface  375  which likewise is sealed off from the interior of the scanner module. Thus elements  371 - 374  and  385  all present blind holes, so that handle  314  may be omitted without the introduction of any exposed apertures leading to the interior of the scanner module. As a modification, batteries may be removed from the terminal body  311 , and all operating power for the scanner and for the terminal keyboard and display and for the RF components may be supplied from batteries in Lie handle  314 . 
     A slide-off battery cap  386  provides access to the battery compartment within handle  314 . 
     The handle may have a trigger  390  for initiating a scan operation, and two of contacts  380  may serve as part of the scan trigger circuit. 
     As a modification which may be taken to be illustrated in  FIGS. 14 and 15 , the terminal batteries may supply all operating power to the RF module  312  and to the scanner module  313 , and in this case handle  314  may be omitted to provide a more compact unitary hand-held data capture device. 
     When handle  314  is omitted, scan trigger actuators may be located at each side of the RF module  312  as indicated at  391 ,  392 ,  FIG. 16 . With this palm supporters arrangement, the device may be held in either the right or left hand, and the convenient one of the trigger buttons  391 ,  392  actuated. 
       FIG. 15  shows a soft rubber guard  401  surrounding a scanner window  402  which may for example serve as an exit window for scan energy (e.g. light energy) and as an entrance window for return scan energy (e.g. modulated reflected light produced by an incident deflected light beam, or a simultaneous reflected light image where the incident light substantially simultaneously covers the entire data source line or lines such, as a complete bar code symbol representing complete product information or the like). 
     In  FIG. 10 , center lines  410  and  411  indicate the axes of elements  351 - 353 ,  357 ,  358  and  354 - 356 ,  359 ,  360 ,  FIG. 13 , and center line  412  shows the axis of the handle attachment screw which engages nut  385 ,  FIG. 15 , to secure the handle  314  in place. 
     In  FIG. 18 , the scanner module may omit connector  340  or leave it unconnected electrically. Instead, the scanner module body is provided with an upstanding end part  420  having a set of spring fingers  421  which engage with the respective external contacts  322 ,  FIG. 11 , on the adjoining end of the terminal. Again the connections may supply terminal battery power to the scanner module, or handle battery power to the terminal, as well as transmitting the same scanner signals between the scanner module and the terminal as in present types of cable connections between RF terminals and scanners. 
     As a further alternative scanner power may be supplied by batteries located in a compartment in section  425  of the scanner module. 
     With batteries in the handle, the center of gravity of the data capture device  310 ′ of  FIG. 18  and of data capture device  310  of  FIGS. 11-17  may be substantially as indicated at  427 ,  FIG. 18 . 
     By way of example,  FIG. 19  illustrates a layout of parts for the case of a scanner module which illuminates a bar code label or other data source simultaneously over its entire extent, the reflected light image being stored in an image sensor array such as a CCD image sensor array for electronic conversion into a scanner data signal. For example, respective elements of the reflected light image may control the generation of charge in respective sensor elements, the charge states being simultaneously transferred to a shift register for readout as a serial scanner data signal. 
     A scanner of the reflected light image-image sensor type is shown in U.S. Pat. No. 4,877,949 issued Oct. 31, 1989. 
     The following tabulation identifies various components shown in  FIG. 19  and indicates parenthetically the related reference numerals from the first and third figures of the incorporated U.S. Pat. No. 4,077,949:
         Illuminator  440  (15, first figure; 35, third figure)   Illumination Voltage Generator  441  (17, first figure)   Automatic Reading Distance Adaptation Means  442  (20, first figure; 103, 105, 102, 101, 90, third figure)   Image sensor means  443  (11, first figure) with photosensor  444  (13, first and third figures)   Control and Processing Means  445  (10, first figure)       

       FIG. 19  departs from the showing in the third figure of the referenced U.S. Pat. No. 4,077,949 in having the reflected image follow a single tier longitudinal path  450  in the relatively thin layer-like scanner module body  313 . In this way, the thickness of the scanner module body  313  may be substantially less than the thickness of the RF data terminal, for example. The reflected image path is altered by a first mirror  451  and a second mirror  452  so that the image path  450  has a single tier path segment  450 A within extension  326  and a single tier path segment  450 B within the main section of the scanner module. 
     To further indicate an exemplary layout of parts, a flex cable  460  may extend from a main circuit board  461  to the illumination voltage generator  441 . A sensor driver circuits component  463  may be located adjacent photosensor  443 . Control and processing means  445  may comprise sensor control circuits  465 , signal detection and shaping circuits  466  and control, communication, and decoding circuits  467 . Component  467  may include host I/O buffer means and host connection means (components 121 and 122 of the first figure of U.S. Pat. No. 4,077,949). Label guide indicator means (21, first figure), and intensity sensing means (14, first figure) are indicated at  471 ,  472  in  FIG. 19 . 
     As represented in  FIG. 19 , and as disclosed in the referenced U.S. Pat. No. 4,877,949, a bar code label or other data source may be read while it is clear of contact with guard means  401  and e.g. at a variable distance therefrom. This is also true with cyclically deflected laser beam scanning systems which may also be contained in scanner modules of the essential configuration of scanner module  313 . 
     In place of the flash tube of the U.S. Pat. No. 4,877,949, a series of bright LED light sources could be used. Illuminator  440 ,  FIG. 19 , may comprise one or more flash tubes or one or more series of LED sources. 
     Where the extension  326  is omitted, or where the extension  326  extends axially of beam path  450 B, the mirror  451  is of course omitted. With use of fiber optics or the like in extension  326 , the extension  326  could be adjustable e.g. from the orientation shown in  FIG. 19  to an in-line orientation aligned with path  450 B. A flexible extension  326  could be manually adjusted to any desired position over a range of positions e.g. from the in-line position (with path  450 A in alignment with path  450 B) to a sharply angled position (e.g. with path  450 A forming an angle of one hundred and fifty degrees relative to path  450 B). 
     The Preferred RF Data Terminal-Scanner Configuration of  FIGS. 10-19   
     The RF data terminal  311 ,  312  as shown in  FIGS. 10 ,  11  and  12  generally may provide the features disclosed in U.S. Pat. No. 4,910,794 issued Mar. 20, 1990 and European Published Patent Application EP/0353759/A2 dated Feb. 7, 1990. The terminal will run application programs downloaded to it, or permanently stored in it, or combinations of both. 
     When the radio module  312 ,  FIG. 11 , is added to the terminal  311 , communication is expanded from direct-wired telecommunication hookups to include real time on-line communication with a host (e.g. a shared data base, applications, etc.). Where the peripheral control card  126 ,  FIG. 10 , is used for terminal  311 , the radio module itself in the preferred embodiment contains not only the transmitter, receiver, associated level adjusts and the scanner connector  334  direct wired back to the control microprocessor of terminal  311 , but also the components  220 ,  222 ,  224  and  226  as illustrated in  FIG. 10 . 
     The scanner module  313  is treated as an add-on peripheral to terminal  311 , governed by the control microprocessor  212 , as indicated in  FIG. 10 . 
     The handle  314  may contain additional batteries for extended operation, and to lower the center of gravity of the device  310  or  310 ′. An option would be to remove the batteries of the terminal to further lower the center of gravity of the device  310  or  310 ′. 
     The intensity sensing means  471 ,  472  (see incorporated U.S. Pat. No. 4,877,949) may be used with a series of bright LED sources as illuminator, driven full on until a near saturation of the photosensor is detected, whereupon the LED sources could be turned off, so that they are treated as a single shot light source. 
     A flex or rigid interface connection may extend between terminal  311  and RF module  312  above the level of sections  335  and  338 . 
     The antenna  104  is offset laterally from connector  334  ( FIG. 12 ) to avoid scanner/antenna electromagnetic interference issues and may be formed with a right angle bend as at  324 ,  FIG. 16 . The length of antenna  104 - 1  beyond bend  324  may be adjusted to various desired angular positions besides the horizontal disposition shown in  FIG. 16 . For example antenna element  104 - 1  may be disposed vertically (as the data terminal is viewed in  FIG. 16 ). 
     The terminal control microprocessor  212 ,  FIG. 10 , controls the supply of battery power to the RF module as represented at  118 - 1 ,  FIG. 10 . 
     The signal levels transmitted at the interface between the low pass filters  222 ,  226  of the terminal peripheral board  26 ,  FIG. 9 , and the transmit and receive level adjusts  204 ,  208  of the RF module  106 , e.g. if used for RF module  312 ,  FIG. 11 , may be standardized to allow terminals and modules to be assembled independently, and then mated in final production, and interchanged in the field, without re-tuning in either case. 
     The base-band processing circuitry could be located in the RF module as in  FIG. 10 , and in this case digital signals would be transmitted at the interface  250  between the terminal and the scanner module. 
     Exemplary scanner technologies which may be used in the scanner modules of the present disclosure include that of U.S. Pat. No. 4,882,476 issued Nov. 21, 1989 and that of U.S. Pat. No. 4,677,949 issued Oct. 31, 1989. The disclosures of U.S. Pat. Nos. 4,877,949 and 4,802,476 are readily applicable to the reading of multiple line bar code indicia. For example, a two dimensional bar code of multiple lines can be envisioned occupying an area of 12.25 square centimeters, e.g. a square with sides of 3.5 centimeters. In accordance with an advantageous development of one of the inventors named herein, marker beams may delineate a field of view of square or circular configuration (e.g. by means of marker beams extending at four corners of a square cross section field of view). The multiline bar code or other area information can be at any random angular orientation within the field of view as delineated by the marker beams, and an area image of the field of view of proper resolution is recorded in a digital image memory, whereupon the digital image may be rotated to a normalized orientation for decoding, for example. While a circular flash tube configuration would be of particular advantage, it is also feasible to utilize linear flash tubes or series of pulse light sources arranged above and below a reader window of suitable configuration, e.g. a rectangular window capable of reading a single line bar code of a length such as five centimeters directly at the reading window, and because of the divergence of the marginal lines (and marker beams) defining the field of view, also capable of reading a single line bar code at any random angle providing the bar code is at a suitable distance from the reader window. The same area reader apparatus would then register a substantial number of line segments of a single bar code as a digital image made up of multiple image lines, or would provide the resolution in orthogonal directions so as to read a multiple line stacked or high density area type bar code pattern of any desired density. A particular advantage of the concepts of modular automatic reader units and modular automatic wireless communication units resides in the ability to adapt these units readily to ever more advanced technological developments, and to adapt the data terminal embodying such modules to a wide diversity of users or applications. For example, modules adapted to different size hands and to left-handed and right-handed users are conceivable. Also various user handicaps could be accommodated. 
     Detailed Description of  FIGS. 20-31   
       FIGS. 20-22  illustrate a modular hand-held data terminal  510  comprised of a user interface terminal portion or module  511  and a hand-held terminal part  512  joining the interface terminal portion along a juncture plane as indicated at  513 . The user interface terminal portion  511  may be comprised of a main keyboard  515  having forty-nine manually actuatable selectors, a display  516 , and a set of special keys  517  which may have a readily removable label panel  518  associated therewith so that label indicia for the respective keys  517  may be readily changed. 
     The hand-held terminal part  512  may be comprised of a battery/controller module  521  with a rounded grip-conforming configuration  522  having a hand trap  521  longitudinally spanning the same. The hand strap  523  may be of elastic material and may have hooks  525 ,  526  which are maintained engaged in receiving blind apertures by virtue of the resiliency of the strap. Module  521  is illustrated as having elongated grooves  531  ( FIG. 21 ),  532  ( FIG. 25 ) which are adapted to receive the fingers of the left or right hand, respectively, when engaged with the grip-conforming configuration  522 . As best seen in  FIG. 25 , module  521  may have a D-subminiature nine pin connector  534  and a further connector  535  which may for example be specifically designed to receive a charger connector of a battery charging unit. 
     In  FIGS. 20-22 , the hand-held terminal part  512  may further comprise a radio module  540  having an antenna  541  and a fifteen pin D-subminiature connector  542  which is part of an end cap  543 . Module  540  provides a downwardly protruding shoulder portion  549  for engaging the user&#39;s hand at one end of grip conforming configuration  522 . 
       FIGS. 23 ,  24  and  25  illustrate the case where the user interface terminal portion or module  511  of  FIGS. 20-22  has been replaced by a substantially wider user interface module  511 - 1  which is readily attached to the hand-held terminal part  512 ,  FIG. 21 , or to the similar hand-held terminal part  512 - 1  of  FIGS. 24 and 25 . It will be appreciated that components  515 - 1 ,  516 - 1  and  517 - 1  of  FIG. 23  generally correspond with parts  515 ,  516  and  517  of  FIG. 20 , except for differences in size, spacing and arrangement. Module  511 - 1  is shown as having a protected recess area  550  for accommodating an antenna  541 - 1  which can be retracted as shown in  FIG. 24  so as to be substantially fully protected by the surrounding walls of module  511 - 1 . 
       FIG. 24  shows the case where the hand-held terminal part  512 - 1  comprises a peripheral module  540 - 1  which may include both a wireless communication unit such as a radio transceiver and also an automatic indicia reader unit such as the optical type of full image automatic reader unit as previously described. Module  540 - 1  is shown as having manually actuatable selectors  551 ,  552  and  553 , preferably of different geometric shape and arranged for actuation by the hand engaging the module  512 - 1  at  522 , 549 - 1 . As shown in  FIG. 22 , there is preferably a corresponding set of selectors such as  561 ,  562  on the opposite side of module  540 - 1 , so that the selectors are conveniently actuatable by whichever hand is gripping hand grip portion  522 . The strap  523  stabilizes the support of the data terminal during manual actuation of selectors such  551 - 553 . The peripheral module  540 - 1  may have an optical reader window such as indicated at  402 ,  FIG. 16 , for effecting reading of a complete line or multiple complete lines of indicia such as bar code symbols. 
       FIGS. 26-28  show a different configuration of user interface module  511 - 2  applied to hand-held terminal part  512  which may correspond identically to that of  FIGS. 20-22 . 
     The user interface module  511 - 2  may have a main keyboard  515  corresponding identically to that of  FIG. 20 , for example. The width of display  516 - 2  may however be intermediate the widths of displays  516  and  516 - 1 . In addition to the special keys  517 - 2  along the lower margin of display  516 - 2 , there is additional a set of manually actuatable selectors  560  along the vertical or Y axis of display  516 - 2  for example at the right margin. The arrangement of keys  560  facilitates providing software labels for these keys by means of the adjacent portions of the display  516 - 2 , where desired. Where the left hand is engaged with the hand grip portion  522 , the strap  523  facilitates the use of the fingers of the left hand to support overhanging portion  564  of the module  511 - 2  during manual actuation of the keys  560 . 
     The module  511 - 2  is indicated as including an automatic full line image reader unit  570  which may include an optical window as indicated at  571  which is directed transversely to the longitudinal axis of the data terminal. With this type of automatic reader, the data terminal is held edgewise during an automatic reading operation, and then may be turned through about ninety degrees about its longitudinal axis so as to place the user module  511 - 2  into its normal orientation for user actuation of the keys and for user observation of the display  516 - 2 . 
     In  FIGS. 29-31 , modules  511  and  521  may be identical to those described with respect to  FIGS. 20-22 , for example. Module  540 - 2  may generally correspond with module  540  except that an automatic reader unit  570 - 1  is applied as an end cap to module  540 - 2  in place of end cap  543 ,  FIG. 21 . Module  540 - 2  is shown as having a swivel type belt clip  573  so that the data terminal can be conveniently supported from a belt or the like worn by the user. The automatic reader unit  570 - 1  may contain an optical window at  574  and may be of configuration so that the data terminal is to be held generally edgewise during an automatic reading operation and then turned through ninety degrees about its longitudinal axis to place the keyboard  515  and display  516  in the optimum orientation for user interaction therewith. By way of example, the optical window  574  may be rectangular and have its long axis substantially parallel to the complete lines of bar code indicia to be read by the automatic reader unit  570 - 1 . 
     Detailed Description of  FIGS. 32-37   
       FIGS. 32-35  show a particularly compact and light weight hand-held data terminal  610  comprising a user interface terminal portion  611  and a hand-held terminal part  612  joined therewith along a juncture plane indicated at  613 . The user interface terminal portion  611  in this embodiment may include a keyboard  615  and display  616  generally corresponding to any of the keyboards herein. 
     Connectors  634  and  635 ,  FIG. 35 , may correspond with connectors  534 ,  535 ,  FIG. 25 , except that in  FIG. 35 , the connector  634  is associated with printed circuit boards within the user interface terminal portion  611 , rather than being associated with modules which provide hand grip portions such as  521 ,  FIGS. 21 ,  24 - 25 ,  27 , and  30 - 31 . 
     The hand-held terminal part  612  may be comprised of a hand grip part  621  and a peripheral module  640 . The hand grip part  621  is provided with a grip-conforming configuration  622  which is of longitudinal extent to receive the user&#39;s hand and is of a rounded configuration so as to comfortably conform to the user&#39;s grip. A battery cover is diagrammatically indicated at  624  for providing access to a battery compartment which may occupy the major part of the space of hand grip portion  621 . 
     The peripheral module  640  may contain automatically operating transducer means comprised of an automatic wireless communication unit and an automatic full image reader unit and thus correspond in this respect with module  540 - 1  of  FIG. 24 . The module  640  may be provided with an antenna  641  corresponding with antenna  541  of  FIG. 21 , or the module  640  may be provided with an antenna corresponding to antenna  541 - 1  of  FIGS. 23 and 24 . An optical window is indicated at  642  which may generally correspond with the window  402  of  FIG. 16  where the automatic reader unit corresponds to an optical reader unit such as described with reference to  FIGS. 11-19 . The window  642  may be housed in a reader extension part  643 . 
     As diagrammatically indicated in  FIG. 32 , module  640  may in the usual case for an optical scanner include a source of light energy for directing light energy outwardly through the window  642  along an axis such as indicated at  645  for illuminating indicia such as a complete line or complete lines of bar code symbols on a label or the like lying at any of a substantial range of distances in front of the window  642 . By way of example, the label with indicia to be read might lie at an optimum focal plane  646 , or might lie in some other plane within the operative range of the automatic reader unit such as the plane arbitrarily indicated at  647 . Reflected light energy may travel along a reflected light energy path such as indicated at  648  which passes through the window  642  and into the interior of the module  640  for conversion into a digital video image, for example, as previously described. 
     The antenna  641  may have a right angle bend portion so that the main antenna part may extend transversely as indicated at  641 - 1  in  FIG. 34 , and may be rotatable from a horizontal disposition such as shown at  104 - 1  in  FIG. 16  to an upright disposition, for example, (as viewed in  FIG. 16 ). 
     As seen in  FIGS. 32 and 35 , module  640  may provide a downwardly curved shoulder portion  649  which my comfortably engage the side of the hand which is in a gripping relation to the hand grip portion  621 . A similar shoulder configuration is indicated at  549  in  FIGS. 21 ,  27  and  30 , and at  549 - 1  in  FIG. 24 . 
     Manually actuatable selectors such as  651 ,  652  in  FIG. 32  may be located symmetrically on each side of the module  640  and may correspond with selectors such as indicated at  551 ,  552 ,  561 ,  562  of  FIGS. 22 ,  28  and  31 . 
       FIGS. 36 and 37  show an identical user interface terminal portion  611  and an identical hand grip terminal portion  621 , but show the module  640  replaced by a module  640 - 1  which may contain only a wireless communication unit such as a radio transceiver. Module  640 - 1  may have manually actuated selectors such as  651 - 1 ,  652 - 1  symmetrically arranged on the respective sides thereof as in the previous embodiments. In  FIGS. 32 ,  33  and  34 , antenna  641 - 1  is shown as being of the right angle type capable of swiveling from a horizontal position such as shown in solid outline in  FIG. 33  to an orientation perpendicular to juncture plane  613 , for example. This type of antenna is of course also applicable to  FIGS. 36 and 37 . 
     As a further example of antenna location, a pair of antennas may be located as indicated at  741 ,  742 ,  FIGS. 36 and 37 , and these antennas may be of a fixed type covered by the dielectric of the module housing so as to be completely enclosed, or for example, embedded in the dielectric walls of the module so as to be partially exposed. It is also possible that various flat type antenna configurations could be located within the dielectric walls of the module  640 - 1 , for example located as generally indicated at  741 - 1 . The antennas  741  and  742  could also be of the retractable/extendable type as indicated at  541 - 1 ,  FIGS. 23 ,  24 . All such antenna arrangements are applicable to each of the embodiments herein including the module  640  of  FIGS. 32-35 . 
     Discussion Re  FIGS. 1-37   
     As used herein the term “data capture” is intended in a broad sense. For example, in warehousing operations, a data terminal may be used in storing goods in predetermined locations, in collecting a list of items from storage locations, or in transferring incoming product directly to outgoing transport means. In the “put away” mode, the data terminal may be used to automatically read product identifying labels at a receiving dock, and to transmit such identifying data e.g. via an RF link to a host computer. The host computer thereby collects data which has been “captured” by the data terminal, concerning arriving product. The central computer may transmit to the data terminal a list of storage locations where the respective incoming items are to be stored. When items are actually stored, a location label at the storage bin and the product label may be read, and a quantity entered manually at the data terminal to indicate to the host computer the actual change in quantity at the storage location. Again the central computer is collecting data actually “captured” by the data terminal in the course of the relevant activity. 
     The automatic operations to be performed by the hand-held data terminal are herein termed “data transducing” operations. For example, in an automatic reading operation, product identification and storage location indicia may be read by transforming reflected light information or electromagnetic code impulses (from a so-called RF tag) into data signals corresponding thereto. Similarly in wireless communication data signals within the data terminal are converted to an energy field (e.g. acoustic, inductive, radio frequency or infrared). 
     A terminal module is a component of a data terminal which is readily removed and readily replaced with the same or different type of component. A detailed example involves components such as  18 ,  FIGS. 1 ,  2 ,  5 , and  118 ,  FIGS. 6 ,  7  and  8 . 
     In preferred forms of modules such as In ( FIG. 5 ),  118  ( FIG. 9 ),  118 - 1  ( FIG. 10 ),  311 - 314  ( FIGS. 11-19 ),  511  ( FIGS. 20 ,  29 ),  511 - 1  ( FIG. 25 ),  511 - 2  ( FIG. 26 ),  521  ( FIGS. 21 ,  24 ,  27 ,  30 ),  540  ( FIGS. 21 ,  27 ),  540 - 1  ( FIG. 24 ),  540 - 2  ( FIG. 30 ),  640  ( FIG. 32 ),  640 - 1  ( FIG. 36 ), the corresponding modules have quick-connect, quick disconnect coupling means exclusively, such as coupling means  38 ,  39 ,  22 ,  23 ,  67 ,  68  ( FIGS. 2 ,  5 ),  86 ,  87  ( FIG. 2 ),  122 ,  123  ( FIG. 8 ),  322  ( FIG. 11 ),  334 ,  340  ( FIGS. 12 ,  13 ),  351 - 356  ( FIG. 13 ),  361 ,  362 ,  371 - 374  ( FIGS. 14 ,  15 ), and  420 ,  421  ( FIG. 18 ). The quick action coupling means may be based on self aligning pin and socket type electric or optic connectors where parts interfit when within the tolerance range of the guiding parts (such as  38 ,  39 ,  FIG. 5 ) or may involve directly engaging surface contacts, or various optical or inductive couplers that merely require alignment within the tolerance range. Preferably also all such modules are readily removed and replaced in the field by the end user, with the use at most of simple hand tools, and with standardized interface levels such that no tuning adjustments or the like are required. A preferred type of module can readily be disconnected, removed as a unit, and replaced with a spare or a different type part. The preferred type of module has defined performance characteristics which permit it to be tested and adjusted as a separate unit, prior to assembly with other terminal components. 
     Certain of the modules herein are disclosed as being capable of operation separately from other normal components of the data terminal. For example, end cap modules  18 ,  118 , and  118 - 1  may be replaced with a simple cover piece which omits connector  19  and all internal parts except e.g. guides  38 ,  39  ( FIG. 5 ). In  FIG. 11 , modules  311  and  313 ,  314 , or  313  alone may have their own batteries (e.g. at  337 , and at  314 ,  FIG. 11 , and at  425 ,  FIG. 18 ). Module  313  has a hand grip region at  375  by which module  313  can be held in the absence of modules  311  anti  314 . Modules  311 ,  312 ,  313  can be held at  375 ,  62 , in the absence of module  314 , and may have individual battery power at  337 ,  425 , or either battery location may supply operating power for all of the modules. Similarly modules such as  511 ,  511 - 1 ,  511 - 2  may contain battery compartments capable of containing batteries which enable separate operation of such modules. A dummy hand-grip module  521  without batteries in its battery compartment may serve the mechanical function of a hand grip only. For example, module  511 - 1  may contain a wireless communication unit associated with antenna  541 - 1  and operated from its own battery power, or battery power from module  521 , with peripheral modules such as  540 ,  540 - 1 , and  540 - 2  all omitted. Thus the modules of  FIGS. 20-31  are preferably essentially completely enclosed and themselves protected from electrostatic discharge, dust, moisture and other contaminants, e.g. to facilitate storage, handling, and separate use as here described. 
     An automatic reader such as  570 ,  FIG. 26 , may be operable as part of module  511 ,  511 - 1  or  511 - 2 , from battery power within this module or from handle module  521 , in the absence of any peripheral module such as  540 ,  540 - 1  or  540 - 2 . A wireless communication unit connected with antenna  541 - 1  may be associated with such a single module or two module system. Alternatively, the interface module or the handle module could contain extensive memory, facilitating batch operation of the one or two module systems. 
     The hand-held terminal parts  512 ,  512 - 1 ,  512 - 2  may also operate entirely separate from the user interface terminal module  511 ,  511 - 1 ,  511 - 2 . For example the peripheral module  540 ,  540 - 1 ,  540 - 2  is already shown as containing manually actuatable selectors such as  551 - 553 ,  561 ,  562 , which may act as manual data input/function selector means. Additional user interface means may include use of marker beams of the automatic reader unit which may flash distinctively or in different colors to signal a good or bad read. A sound generator may generate various tone patterns to communicate with the user as to mode selected, good read, etc. Further, modules,  540 ,  540 - 1 ,  540 - 2  may contain voice recognition and/or voice synthesis devices to facilitate user supervision of the terminal parts  512 ,  512 - 1 ,  512 - 2 . Such voice input/output interface means may be located on the side face of module  540 ,  540 - 1 ,  540 - 2  opposite the reader optical window such as  571  or  574 , so that the orientation of the terminal part during automatic reading is essentially identical to the normal orientation which is optimum for user interaction with the voice recognition input and with the voice synthesis output of the module. That is the input microphone and output loudspeaker would be directed toward the user, while the optical window such as  571  or  574  would be directed away from the user, the longitudinal axis being generally vertical, and the juncture plane generally bisecting the user, and being generally at right angles to the plane of a label being read. 
     Modules such as  511 ,  511 - 1 ,  511 - 2  when self powered, may be constructed so that their coupling means (e.g. acoustic, infrared, inductive, etc.) are operable e.g. directly across the juncture plane  513  in the full data terminal configuration, and also at various distances from the hand-held terminal part  512 ,  512 - 1 ,  512 - 2 . Such an arrangement is advantages where the interface part  511 ,  511 - 1 ,  511 - 2  can be conveniently mounted on a goods transport device while the user may leave the transport device to actually handle products being collected or put away. With the strap  523 , the part  512 ,  512 - 1 ,  512 - 2  can be carried at the wrist or forearm with both hands free when needed. The module  511 ,  511 - 1 ,  511 - 2 , can display a put away list of items and locations, or a pick list of goods to be collected and locations thereof, and be referred to when the operator returns to the transport device. 
     The grooves  531 ,  532  may facilitate mounting the complete data terminal or terminal part  512 ,  512 - 1 ,  512 - 2  in a holder which may provide two ribs designed to engage in the respective grooves, and to rest against the end walls  531 A,  532 A at the upper ends of the grooves. The hand strap  523  may be compressed toward hand grip  522  as the part  512 ,  512 - 1 ,  512 - 2  is lowered into such a holder e.g. where the holder is affixed to a belt on the user&#39;s waist. The different width modules  511 ,  511 - 1 ,  511 - 2  are not a problem (as they would be with an enclosing holster type carrier). 
     A docking system for receiving terminal part  512 ,  512 - 1 ,  512 - 2  for recharging of batteries, and data uploading to a host and/or data or program downloading to the terminal may similarly have ribs designed to engage in the respective grooves  531 ,  532 . 
     It is also conceivable to provide the user interface terminal module  511 ,  511 - 1 ,  511 - 2  with blind undercut slots or blind keyhole type slots for receiving the hooks  525 ,  526  or other end fittings of a resilient hand strap  523  when module  511 ,  511 - 1 ,  511 - 2  is separate from part  512 ,  512 - 1 ,  512 - 2 . In this way, the module  511 ,  511 - 1 ,  511 - 2  may be worn on one wrist or forearm sodas to face the user, while the terminal part  512 ,  512 - 1 ,  512 - 2  is worn on the other wrist or forearm in a disposition where an automatic reader such as  570  or  571 - 1  is ready for use. Again both hands can be available for the safe lifting of relatively heavy items to be stored, collected or transferred. A voice recognition unit may conveniently control automatic reading operation and/or the reader may have a pulsed proximity detector for measuring distance and for automatically effecting a reading operation when a label is within the operative reading range. Pulsed marker beams can be used to assist the user in keeping the label within the field of view once the distance measurement system is enabled until a valid reading has been obtained. 
     With automatic reader units such as  570  and  570 - 1  which are directed laterally, it may be desirable to accommodate users who would desire to hold part  512 ,  512 - 2  with the right hand and actuate selectors  515 ,  517 - 2 ,  560  with the left hand. To this end, module  511 - 2  could be replaced with a module where window  571  was directed laterally to the left (as the user interface is to be viewed in  FIG. 26 ), and overhang  564  and keys  560  were laterally to the left of part  512 . 
     In an arrangement such as indicated in  FIG. 30 , module  540 - 2  could be replaced with a module having a reader optical window directed in the opposite lateral direction from window  574 , and e.g. an antenna on the opposite lateral side of the module from antenna  541 ,  FIG. 31 . 
     As a further alternative, antenna  541 ,  FIG. 31 , could be rearranged as described with reference to  FIG. 32 , and as shown at  741 ,  742  or  741 - 1 ,  FIGS. 32 ,  34 , to permit end cap  570 - 1  to form a separate module which may engage with module  540 - 2  in either of two opposite orientations, one as shown in  FIG. 30 , and the other with optical window  574  directed in an opposite sense. The module  570 - 1  may contain its own battery, decoder and communication interface for serial communications of decoded bar code data signals over a central optical interface channel which is aligned with a cooperating optical channel of module  540 - 2  in either orientation of module  570 - 1 . 
     In another conceivable embodiment, a base section of a reader module e.g. containing batteries, decoder and communications interface could plug into a connector such as  542 , carried by a peripheral module at  540 - 2 . The reader module base would occupy the space of reader unit  570 - 1  prior to window  574 . The reversible part of the reader module would e.g. have a coiled cable secured with the base section so as to accommodate either of the opposite orientations of the window of the reversible part of the reader module. 
     Any of the terminals or terminal parts with automatic reader modules could be clipped to the user&#39;s belt and used as hands free readers. A clip such as  573 ,  FIG. 30 , could mount terminals such as shown in  FIGS. 27 and 30 , with the longitudinal axis vertical, and could mount module  313  (without handle  314  or modules  311 ,  312 ) with the juncture plane vertical and the longitudinal axis horizontal. Similarly, a belt clip such as  573  or two such clips could mount terminal  610 ,  FIG. 32 , with its juncture plane  613  vertical, so that reading axis  645  would be directed toward a work area in front of the user. An angularly adjustable extension such as described for extension  326  could adjust the field of view to conveniently impinge on the work area. 
     Pulsed marker beams would facilitate the user&#39;s positioning of successive items, and distinctive sounds, marker beam flashes or colors, etc. could signal a successful read of each successive item. As previously mentioned the reader module could operate in a proximity detect mode. The data terminal could emit a distinctive sound whenever a label came within the field of view and within an appropriate range of distances, and actual reading would take place automatically (during an interval when all marker beams were off). The marker beams could be pulsed automatically only when an acoustic proximity detector sensed that a label was in alignment with the field of view, so as to conserve battery energy during such hands free operation of the reader unit, if desired. 
     Any of the displays herein may be capable of presenting any arbitrary graphical display, e.g. individual handwritten signatures, so that a person&#39;s signature can be compared with an authorized signature stored in the data terminal and displayed on the terminal display. 
     Furthermore the displays herein may incorporate high resolution digitizers. Where the digitizer is transparent, the digitizer field may be superimposed over the display layers. Signatures may be captured on a stroke sequence basis for dynamic comparison with a stored authentic signature. Pressure variations may also be stored and compared. See for example U.S. Pat. No. 4,793,810 issued Dec. 27, 1988, and U.S. Pat. No. 4,798,919 issued Jan. 17, 1989. 
     A combined digitizer/display is shown for example in U.S. Pat. No. 3,764,813 issued Oct. 9, 1973. This digitizer avoids the use of touch wires which would tend to obstruct the displayed information. It is apparent that a square digitizer/display, for example, may use angularly swept light beams e.g. at the four corners each sweeping the digitizer area. By using a square array of photosensors for following the successive sweeps, the stylus location could be accurately tracked. With multiple layers of photosensors, stylus pressure could also be recorded. Stepping motors, for example, could be used to sweep the light sources through ninety degrees clockwise during one scan, and then through ninety degrees counterclockwise for the next scan at cacti corner. Each laser source may be pulsed on and off after each step of its stepping motor, and the stepping actions of the respective motors may be sequentially offset to minimize the interval between pulsing of the successive laser sources. Arrays of photodetectors along the sides of the digitizer area could have single outputs since the pulsing of the laser sources would indicate the time when the absence of an output pulse represented a beam obstructed by the stylus. The production of rectangular cross section beams of good resolution over a substantial working distance and the cyclical deflection of such beams are familiar to those in the field of laser bar code scanners, so that two or more laser sources would be sufficient for sensing both area position and contact pressure. 
     The user interface means of any of the embodiments herein or replacement user interface modules may provide for handwritten printing or cursive data input including provision for signature capture and verification. 
     The optical full image automatic reader units disclosed herein or provided by replacement modules may have resolution to capture automatically a complete signature written on a delivery receipt or the like for digital storage and automatic validation based on a digitally stored authentic signature. 
     Where the marker beams are only active when an acoustic range finder signals that a target is within range and generally in the field of view, a central aiming visible light beam may be pulsed whenever the acoustic range finder is active, to facilitate aiming of the optical reader. When the target is within range, the aiming light beam is de-activated to save battery power, and flashing of the marker beams begins to facilitate bringing the multiple lines of indicia into the area field of view. The marker beams may diverge according to the increasing size of the field of view with increasing distance to more precisely delineate the field of view. 
     The aiming visible light beam is also useful with directional type RF-tag systems, e.g. systems operating at relatively high frequencies. The flashing of the aiming light may be terminated automatically as soon as a valid reading has been obtained. 
     With signature verification, and also with bar code reading of bar codes at random angles, the digital image obtained can be displayed on a display of the terminal along with a normalization line. The operator can rotate the normalization line with a manual control to indicate any pronounced slant of the signature or to indicate the angle of a single or multiple bar code stored image. The processing program can rotate the stored image, and display the normalized signature or bar code image prior to validation processing or decoding. 
     A bar code image can automatically be normalized before decoding for example, by detecting linear segments of memory cells which all represent dark pixels, and thereby establishing the slope of the bars of the bar code. Such an algorithm can be designed to quickly locate a dark bar as a first step. For example, a digital memory may contain a bar code image representing a bar code three centimeters long by 1.7 centimeters tall, and within an area field of view four centimeters by four centimeters. By exploring horizontal lines of memory cells at one centimeter intervals and then exploring vertical lines of memory cells at one centimeter intervals, a given line of memory cells could be identified with the largest number of black pixels, (e.g. each assigned a value of one). By selecting a sequence of black cells along the selected line, and exploring memory cells on each side of the selected line, the probable slope of a given black bar could be quickly as ascertained. A check would be to examine a set of memory cells along a line at right angles to the probable slope of the bars. If such a line encountered the proper number of bars, the digital image could be rotated according to the probable slope value. A refinement would be to select a sequence of black cells along the selected line closest to the minimum bar width since the slope of a minimum width bar is more accurately determined in a minimum of steps. Once the bars were approximately vertical in memory, spaced horizontal lines of memory cells could be examined, and further rotational correction could be effected if desired. 
     If several spaced lines of memory cells did not render the same bar code number, once the bar code image was normalized, the image could be discarded, and a further image examined. Voice synthesis means could instruct the user to aim the automatic reader up or down, left or right, if the bar code image was found to be only partly registered in image memory. 
     It will be apparent that features of the various embodiments illustrated or described herein may be combined, and that various of the features may be utilized independently of others, and that many further modifications and variations may be effected without departing from the scope of the teachings and concepts of the present disclosure.