Abstract:
A bar code scanner for either fixed or hand-held disposition at a counter. The scanner includes a compact housing including a spherical head with a window and a downwardly protruding stem, and a sliding carriage attached to the base of the stem. The stem and sliding carriage cooperate with arcuate guide rails in the compact base for positioning the window via pivoting the head about a horizontal axis. An omni-directional scanning assembly is mounted in the head and this includes an object detection circuit for detecting and determining the presence of an object within an operative scanning field, a light source for generating a laser beam when an object is within the scanning field, a scanning mechanism for scanning the light beam across the object and its bar code, a photoreceiving circuit for receiving light reflected from the bar code, an A/D converter for generating a digital signal representing the light reflected from the bar code, and processing and control circuitry for decoding the bar coded-information and controlling overall system flow.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation-in-part of applications Ser. No. 08/645,335, filed May 13, 1996, and Ser. No. 08/645,331, filed Sep. 24, 1996, both of which are continuations-in-part of application Ser. No. 08/645,486 filed May 13, 1996 (now U.S. Pat. No. 5,796,091), which is a continuation-in-part of Ser. No. 08/615,054 filed Mar. 12, 199, which is a continuation-in-part of: application Ser. No. 08/573,949 filed Dec. 18, 1995: application Ser. No. 08/292,237, filed Aug. 17, 1994 (now U.S. Pat. No. 5,808,285); application Ser. No. 08/365,193, filed Dec. 28, 1994 (now U.S. Pat. No. 5,557,093): application Ser. No. 08/293,493 filed Aug. 19, 1994, (now U.S. Pat. No. 5,525,789); application Ser. No. 08/561,479, filed Nov. 20, 1995; application Ser. No. 08/278,109, filed Nov. 24, 1993, (now U.S. Pat. No. 5,484,992); application Ser. No. 08/489,305, filed Jun. 9, 1995; application Ser. No. 08/476,069, filed Jun. 7, 1995; and application Ser. No. 08/584,135 filed Jan. 11, 1996, now U.S. Pat. No. 5,616,908. 
     The present application is also a continuation-in-part of application Ser. No. 08/943,627, filed Oct. 3, 1997, which is a continuation of application Ser. No. 08/865,257, filed May 29, 1997, which is a continuation of application Ser. No. 08/475,376, filed Jun. 7, 1995 (now U.S. Pat. No. 5,637,852), which is a continuation of application Ser. No. 08/365,193, filed Dec. 28, 1994 (now U.S. Pat. No. 5,557,093), which is a continuation of application Ser. No. 08/036,314, filed Mar. 24, 1993 (now abandoned), which is a continuation of application Ser. No. 07/580,738, filed Sep. 10, 1990 (now U.S. Pat. No. 5,216,232). 
     The present application is also continuation-in-part of applications Ser. No. 08/850,295 filed May 14, 1997, which is a continuation of application Ser. No. 08/439,224, filed May 11, 1995 (now U.S. Pat. No. 5,627,359). 
     The present application is also a continuation-in-part of application Ser. No. 08/827,118, filed Mar. 27, 1997, which is a continuation of application Ser. No. 08/584,135, filed Jan. 11, 1996 (now U.S. Pat. No. 5,616,908). 
     The present application is also a continuation-in-part of application Ser. No. 09/204,176, filed Dec. 3, 1998. 
     All of the aforesaid applications are commonly owned by Metrologic Instruments, Inc., of Blackwood, N.J. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to bar code scanners and, more particularly, to an improved ergonomic bar code scanning system having a compact housing for either fixed or hand-held disposition at a counter. 
     2. Description of the Background 
     Many commercial scanning systems are available for scanning bar codes, e.g., the UPC or EAN bar codes, which are imprinted on products or packaging. 
     One type of scanning system is generally referred to an omnidirectional scanner. Often these devices can be found mounted in a checkout counter of a supermarket or other retail point-of-sale environment. These scanning systems include a scanning window or aperture at the front of the scanner housing through which a scanning pattern is projected. The scanning pattern is created by a light source, typically a laser, and associated optical components that may produce a pattern of multi-directional scan lines. When an item bearing a bar code is brought into the field of the scan pattern so that at least one of the scan lines completely traverses the bar code, light is reflected off of the bar code and is received back through the window. The reflected light is detected by a photodetector or other light detection means. The signal from the photodetector is then processed by conventional means and forwarded to a microprocessor or other device which decodes the bar-coded information. 
     In-counter and presentation type scanners use a variety of optical configurations including mirrors, prisms and the like to fold the laser beam and create complex omnidirectional scanning patterns in order to insure that the bar code is scanned completely by at least one scan line so that it can be read accurately irrespective of its orientation within the scan pattern. Examples of such omnidirectional scanning patterns include: comb patterns, orthogonal patterns, interlaced patterns, star-like patterns, lissajous patterns and the like. While such prior art scanners may be suitable for their purpose, their physical configuration of the optical components necessary to produce such complex omnidirectional scanning patterns has resulted in scanner housings which are quite large in size and necessarily fixed. 
     Additionally the scanning window or aperture generally faces in a single direction. To change the direction of the scanning window and thus the direction of the scanning pattern, it was necessary to move the entire housing. In many applications, this is inconvenient, especially where there is limited counter space. 
     There have been various approaches to the problem. For example, U.S. Pat. No. 4,713,532 discloses a counter or slot scanner producing an aggressive scanning pattern having three rastered groups of intersecting scans that form a large “sweetspot” to enable the bar code to be read omnidirectionally. The &#39;532 scanner has a compact housing with a relatively small “footpront” which can be mounted on or in a counter. Depending upon the orientation of the scan, its window may be horizontal, vertical, or at some other orientation. Devices embodying the teachings of that patent have been sold by the assignee of that patent (and of this application), Metrologic Instruments, Inc., under the designation MS260. However, once the scanner housing was positioned at a particular orientation, it was fixed and could not be easily moved. 
     In U.S. Pat. No. 5,216,231, to Knowles et al., an omnidirectional presentation scanner is disclosed. This scanner was designed to be mounted above the counter on an adjustable base. The base is constructed to allow the scanner housing to be adjusted in multiple directions so that the scanning pattern is projected in and desired orientation with respect to the counter. However, the base must be permanently secured to the countertop, which prevents the scanner from being lifted by hand to scan large or bulky items which do not fit on the countertop. 
     U.S. Pat. No. 5,767,501 to Schmidt et al. discloses a hand-held automatic portable bar code symbol scanner with an omnidirectional laser scanning platform mounted in the head of a hand-supportable housing. The hand-supportable housing can also be supported in separate base unit for hands-free omnidirectional presentation type scanning. The base unit is designed to be attached to a counter and is equipped with a pivoting receptacle, which allows the scanning window and therefore the projected scanning pattern to be adjustable about a horizontal axis. While this unit adds great flexibility and makes efficient use of counter space, it requires the user to return the hand-supportable housing to the base unit after each scan requiring alignment of the handle and handle receiving portions. Additionally, while the hand-supportable housing itself is compact, the combination of the hand-supportable housing with the base unit can be bulky and cumbersome in the valuable counterspace of the typical point-of-sale environment. 
     U.S. Pat. No. 5,479,002 to Heiman et al. discloses another partial solution in the form of a scan head that is adjustably mounted in a ball-and-socket joint on a scan module or housing. The scan head is movable about three mutually orthogonal axes, thereby allowing the operator to steer the light beam emitted from the head. However, the &#39;002 patent does not disclose or suggest how the scan head and lower housing can be combined in a package that is conveniently hand-held as well as free-standing. Moreover, the design of the &#39;002 housing as disclosed provides only for a single-line scan pattern and would not easily lend itself to the production of an omnidirectional scanning pattern. 
     Other attempts to produce compact omnidirectional scanners having adjustable housings or bases include the Symbol Technologies, Inc. Model LS 9100 and the PSC Model Duet omnidirectional scanners. Both units require removal of the hand-held scanner housing from the associated stand for hand-supported scanning. 
     Consequently, a need remains for a compact scanner configuration incorporating an integral base with an omnidirectional scanning head that is easily adjustable about at least one axis with respect to the base. The scanner being capable of aggressive omnidirectional scanning from both a hands-free standing position on a countertop or hand-supported by a user for scanning lager, bulky items with out requiring the user to remove and/or replace the scanner in its stand. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the present invention to provide an omnidirectional scanner of compact size, configured with an integrated base and scanning head, wherein the scanning head is easily adjustable with respect to the base, the entire unit being capable of economical manufacture. 
     It is another object to provide a scanner as described above in which the scanner head is rotationally attached to the base by a dual track sliding support mechanism that results in an extremely rugged and durable integral scanning unit, whereby the head unit pivots easily with little or no friction against the base unit. 
     It is still another object to provide a bar code scanning system having an improved ergonomic compact housing for hand-held use in which the scanner housing has contoured lateral recesses on opposing sides to fit the hand of the user by providing thumb and finger grips. 
     It is another object to provide for a scanner having an improved design in which the scanner base provides a secure foundation for the pivoting the scanning head, and yet very little counter space is needed. 
     It is still another object to incorporate an aggressive and reliable omnidirectional scan platform in a housing as described above, the resulting system being capable of an aggressive omnidirectional scan from a free-standing fixed position on a countertop or while handheld by a user. 
     According to the present invention, the above-described and other objects are accomplished by providing a compact scanner including an improved ergonomic scanner housing. The scanner housing is formed of two parts, a base unit and a scanning head. The base unit has an upwardly directed curved opening and a pair of opposing arcuate guide rails attached to the inner wall of the base unit below the opening. Mounted to the base unit is the scanning head housing an omnidirectional scanning platform. The scanning head has an exterior curvature conforming to the curved opening of the base unit for rotational seating thereon. A neck portion protrudes from the bottom of the scanning head. The neck portion extends into the opening in the base unit for sliding engagement with the opposing guide rails. In this manner, the scanning head is supported within the opening of said base unit by the guide rails. The guide rails also permit the scanning head to pivot about a horizontal axis while supporting the head to minimize friction. 
     An omnidirectional scanning platform is housed in the scanning head. The scanning platform includes a light source for generating a light beam, a scanning mechanism and associated optics for producing an omnidirectional scanning for projection through a scanning window for scanning a bar code on abject presented to the scanning pattern, a light collector for a collecting light returned from the bar code, a photodiode for receiving light reflected from said bar code, an A/D conversion circuit for processing the signal produced by the photodiode, a microprocessor for decoding bar-coded information from the reflected light, and a control system for controlling the function of the above components. 
     The resulting scanning system permits an aggressive omnidirectional scan from a free-standing fixed position atop a counter or while handheld by a user. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiment and certain modifications thereof when taken together with the accompanying drawings in which: 
     FIG. 1 is a perspective view of a presentation bar code symbol scanner  10  having an omnidirectional laser scanning platform mounted in the head portion of a multi-purpose hand-supportable/free-standing housing according to one embodiment of the present invention. 
     FIG. 2 is a rear view of the presentation bar code symbol scanner  10  of FIG.  1 . 
     FIG. 3 is a side view of a circular housing bumper  20 . 
     FIG. 4 is an exploded perspective view of the scanner  10  of in FIGS. 1-3. 
     FIG. 5 is an exploded perspective view of the scanner  10  showing a cross-sectional view of the base unit  60 . 
     FIG. 6 is a side cross-sectional view of the scanning head  12  showing the internal component layout. 
     FIG. 6A is side view of the optical bench  34  of FIG. 6 showing the optical bench layout. 
     FIG. 7 is a front view of one embodiment of the scanner  10  showing the internal optical layout. 
     FIG. 8 is a front view of a second embodiment of the scanner  10  showing the internal optical layout. 
     FIG. 9 is a perspective view of base unit  60 . 
     FIG. 10 is a schematic block diagram of first exemplary embodiment of the automatically-activated scanning system of the present invention. 
     FIG. 10A is a schematic representation of second embodiment of an automatically-activated scanning system of the present invention. 
     FIG. 11 is a schematic representation of third embodiment of the automatically-activated scanning system of the present invention. 
     FIG. 11A is a schematic representation of a fourth embodiment of the automatically-activated scanning system of the present invention. 
     FIG. 12 is a top view of guide plate  40  of FIGS. 4 and 5. 
     FIG. 13 is a side view of the guide plate  40  of FIG.  12 . 
     FIG. 14 is a side view of a slide rail  70  of FIG.  5 . 
     FIG. 15 is a top view of the slide rail  70  of FIG.  14 . 
     FIG. 16 is a front view of the slide rail  70  of FIGS. 14 and 15. 
     FIG. 17 is a perspective view of the optical bench  34  of FIGS. 6 and 6A stripped of optical components., 
     FIG. 17A is a top view of the light collecting mirror  33 . 
     FIG. 18 is a side view of the optical bench  34  of FIG.  17 . 
     FIG. 19 is a front view of the scanner  10  showing the omnidirectional scanning pattern at the face of the unit. 
     FIG. 20 is a front view of the scanner  10  showing the omnidirectional scanning pattern at 2.5 inches away from the face of the unit. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 is a perspective view of a portable bar code scanner  10  incorporating an omnidirectional laser scanning platform according to one embodiment of the present invention. The scanner  10  generally includes a scanning head  12  that is rotationally connected to a base unit  60 . The scanning head  12  houses all associated optical components of the omnidirectional laser scanning platform as will be described in detail hereinafter. 
     FIGS. 1 through 4 show the general construction of the scanner housing. The scanning head  12  has an aperture  11  through which an omnidirectional scanning pattern is projected. The scanning head  12  is formed in a generally spherical configuration with a flat front window  14  and top-mounted LED power and good read indicator  50 . The head unit  12  is preferably molded of hard plastic or the like, and can be formed in two half-sections with tongue-and-groove edges for an interlocking fit. The scanning window  14  is generally round in configuration and mounted in a circular housing bumper  20 , which is in turn mounted in the aperture  11  in the scanning head  12 . As shown in FIG. 3, the window  14  is seated at an angle within a groove (not shown) formed in the housing bumper  20 . 
     The housing bumper  20  has a beveled outer lip  26  and an inner lip  24  with a channel  25  formed therebetween. The channel  25  engages the inner edge of the aperture  11  of the scanning head  12 . Additionally the housing bumper has a pair of locking rib members  23  which further engage a corresponding protrusion  21  on the interior of the scanning head  12 . (See FIG. 6) The combination of the channel  25  and the locking rib members  23  acts to secure the window  14  and the housing bumper  20  to scanner housing  10 . The housing bumper  20  acts to protect the front of the scanner head  12  and to cushion the scanning window  14  against damage if the unit dropped or banged. The window  14  is a round section of transparent acrylic-type plastic with optical filtering properties such as described in detail in U.S. Pat. No. 5,627,359 (the &#39;359 patent being commonly owned by Metrologic Instruments, Inc. and incorporated herein by reference). The size and shape of the scanning window and housing bumper can be varied from the size and shape shown without changing the performance of the scanner. 
     FIG. 2 is a rear view and FIG. 4 is an exploded view of the scanner  10  of FIG. 1 in which the improved ergonomics of the design are apparent. The base unit  60  has a contoured top opening  61  for receiving a neck portion  16  of the substantially spherical scanning head  12 . The contour of the opening  61  is curved upward to provide ergonomic support for the spherical scanning head  12  and an aesthetically pleasing scanner  10  (as was shown and claimed in Applicant&#39;s corresponding U.S. Design Pat. No. D 408,806). The bottom portion of the base unit  60  has contoured lateral recesses  15  and  17  on opposing sides to provide thumb and finger grips as shown in FIG.  2 . During hand-supported operation of the scanner  10 , the user can easily grip the scanner  10  in one hand by the contoured lateral recesses  15  and  17  and lift it off of a countertop surface to scan a large or bulky item. 
     FIG. 4 details the component parts of the scanner housing and their assembly into the scanner  10 . As shown, the neck portion  16  of the scanning head  12  is inserted into the contoured opening  61  in the base unit  60 . Base unit  60  rotationally supports the head unit  12  and houses a printed circuit board (“PC board”) which includes circuitry and electronics related to the functions digitizing, decoding, formatting and transmitting bar code symbol character data produced in the scanning head  12 . Other related circuitry which cannot be supported in the scanning head  12  can also be located on the PC mounted in the base unit  60 . The scanning head  12  can easily be pivoted about a horizontal axis with respect to the base  60  allowing a user to position the scanning window  14  and therefore the projected scan pattern in a plurality of directions. 
     The neck portion  16 , once inserted into base unit  60 , rests atop two opposing guide-rails  70  mounted on the interior side walls of base unit  60 . The guide rails  70  snap fit onto correspondingly-shaped protrusions  71  formed in the interior side walls of base unit  60 . The guide rails  70  are formed of smooth plastic and provide direct support and cushioning for the scanning head  12 . The underside of neck  16  has a pair of arcuate indentations  22  on opposite sides of the neck. The guide rails  70  are curved to conform to the indentations  22  on the underside of neck  16  and in general to the spherical outer surface of the scanning head  12 . 
     FIGS. 14,  15  and  16  are a side view, top view and front view, respectively, of the right-side guide rail  70  which is exemplary of both guide rails. Guide rail  70  is an arcuate bracket that snap fits onto a correspondingly-curved protrusion  71  formed on the interior side walls of the scanning head  12  via a groove  77  formed along the bottom edge of the guide rail. 
     Each guide rail  70  has a planar side-wall portion  72 , a front spacer bracket  78 , a reinforcing rib  76 , and an arcuate slide rail  74  protruding laterally from the bottom edge of each side-wall portion  72 . Slide rail  74  is the exterior of groove  77 . Once the groove  77  has been fitted to protrusion  71 , slide rail  74  extends into the center of the base unit  60 . 
     When the guide rails  70  are attached to the interior of the base unit  60 , opposite each other, they provide slidable support for the neck portion  16  and the scanning head. The indentations  22  formed in the side of neck portion  16  rest on slide rails  74 . The exterior spherical surface  27  of the scanning head  12  rests on the upper edge of the side-wall portion  72  of guide rails  70 . When scanning head  12  is rotated about a horizontal axis, the indentations  22  in neck  16  slide against the slide rails  74  of the guide rails  70 . The front spacer bracket  78  and reinforcing rib  76  further act to support, position and cushion the scanning head  12  on the base unit  60 . 
     As seen in FIGS. 4 and 5, a guide plate  40  attaches to the underside of neck portion  16 , and guide plate  40  traverses the opposing guide rails  70  to moveably connect the scanning head  12  to the base unit  60 , thereby pivotally securing the scanning head  12  to the base unit  60 . 
     FIGS. 12 and 13 are a top view and a side view, respectively, of guide plate  40 . Guide plate  40  is a substantially rectangular panel that has a pair of parallel tabs  42  and  48 , front and back, that fit within corresponding notches  43  on the underside of neck  16  to position the guide plate  40 , and two screw holes  45  to facilitate screw attachment to neck  16 . Openings  46  and  47  allow for the pass through of electrical connections. During rotation of the scanning head  12 , the guide plate  40  similarly slides against underside of slide rails  74  identical to the movement of the underside of the neck  16  against the top side of slide rails  74 . When the neck  16  is seated on seated on guide rails  70 , the indentations  22  rest against slide rails  74  and the neck fits snugly between the guide rails  70 . During rotation of the scanning head, the guide rails  70  provide both lateral and elevational support for the scanning head  12 . This support by the guide rails  70  prevents the outside of the scanning head  12  from constantly brushing against the curved opening  61  of the base unit  60 , which in turn keeps the outside surface of the scanning head  12  from being scratched by the repetitive motion of rotating the head  12  with respect to the base  60 . 
     FIG. 9 is a perspective view of base unit  60  with guide rails  70  installed therein. The curved configuration of the guide rails  70  and the opening  61  provides a first pivot point of radius r 1  extending from the contoured opening  61  of base unit  60  about the horizontal axis of head unit  12 , and a second pivot point of radius r 2  extending from the guide rails  70  to the same horizontal axis of head unit  12 . This dual-radius orbiting support configuration results in an extremely rugged and durable scanning unit in which the scanning head  12  pivots easily about a horizontal axis with little or no friction against the base unit  12 . When used as a fixed scanner, the base unit  60  provides a well-balanced, stable and protected foundation for head unit  12 , and yet very little counter space is needed. 
     Referring back to FIG. 4, a bottom plate  80  is a substantially planar member that attaches to the underside of base unit  60  by four screws through screw holes  82 , thereby sealing it off. Rubber feet can be secured to the underside of bottom plate  80  to cover the screw heads and to improve the footing of the scanner. Additional screw holes  84  may be provided as desired to allow for mounting the scanner in a fixed manner to a countertop, wall or other fixed position. Preferably, a collar  86  protrudes upwardly from bottom plate  80  and fits into an opening provided in the base unit  60 . The collar  86  has an opening  62  for the insertion of a power or communication cable. The bottom plate  80  and collar  86  are configured to fit flush with the bottom of base unit  60  with the collar  86  fitting snugly into opening  62 . This configuration aids assembly and reinforces collar  86  to provide a rugged passage for electrical cabling. 
     The bottom plate  80  additionally provides support for a second PC board (not shown) which holds circuitry for digitizing, decoding, formatting and transmitting bar code symbol character data. Cabling also connects an analog signal processing board  52  (to be described) that is mounted in the scanner head  12  to a signal decoding board in the base unit  60 . The cables are passed through openings formed in the neck portion  16  of the scanning head  12  and the guide plate  40 . 
     The compact housing configuration described above yields a convenient, durable and ergonomic scanner package having a scanning head  12  that can be tilted vertically about a 30° angle with respect to the base unit  60 . Thus, the scanner is structurally capable of an aggressive omnidirectional scan from a free-standing fixed position atop a counter or while handheld by a user. 
     The flexibility of the housing as described above is matched by an aggressive and reliable omnidirectional laser scanning platform. The scanning platform inclusive of all associated optical and electrical components is mounted in the head unit  12  and projects a pattern of scan lines through front window  14  onto a bar code to be read. 
     FIGS. 19 and 20 show the omnidirectional scanning pattern  13  as it is projected at the light transmission window  14  and 2.5 inches from the window  14  of the scanner  10 . 
     The omnidirectional laser scanning platform of the present invention generally employs an optical layout that is substantially similar to the optical layout taught in U.S. Pat. Nos. 5,637,852 and 5,844,227, that are incorporated by reference herein. As shown in FIGS. 6,  6 A and  7  an exemplary laser scanning platform according to the present invention is mounted within the head portion  12  of the scanner housing  10 . The laser scanning platform includes an assembly of subcomponents assembled upon an optical bench  34  with respect to a central longitudinal reference plane. 
     The subcomponents assembly includes: a scanning polygon  36  having four light reflective surfaces  36 A,  36 B,  36 C and  36 D, each disposed at a tilt angle with respect to the rotational axis of the polygon; an electrical motor  37  mounted on the optical bench and having a rotatable shaft on which polygon  36  is mounted for rotational movement therewith; an array of stationary mirrors  38 A,  38 B,  38 C,  38 D and  38 E fixedly mounted with respect to the optical bench; a laser beam production module  39 , fixedly mounted above the rotating polygon  36  for producing a laser beam having a circularized beam cross-section, and essentially free of astigmatism along its length of propagation; an analog signal processing board  52  fixedly over the rotatable polygon  36  and carrying a photodetector  51  for detecting reflected laser light and producing an analog signal, and signal processing control circuits  53  for performing various functions, including analog scan data signal processing; a light collecting mirror  33 , disposed above the array of stationary mirrors  38  for collecting light rays reflected off the rotating polygon  36  and focusing the same onto the photodetector  51  on the analog signal processing board  52 ; and a beam directing surface  32 , realized as a flat mirror mounted on the light collecting mirror for directing the laser beam from the laser beam production module  39  to the rotating polygon  36  disposed there beneath. 
     The laser beam production module of the present invention could be accomplished by employing a system of a lens and aperture as is well known in the art, a system which employs a plurality of diffractive optical elements (DOEs) for modifying the size and shape of the laser beam. Various embodiments of DOE-based laser beam production modules are shown and described in co-pending application Ser. No. 09/071,512 filed on May 1, 1998, commonly owned by the applicant hereof and incorporated by reference herein. 
     In FIGS. 17,  17 A and  18 , the optical bench  34  is shown in greater detail, with the polygon  36 , scanning motor  37 , laser beam production module  39 , collector mirror  33 , and stationary mirror elements  38 A through  38 E removed for illustration purposes. As shown, stationary mirror brackets  44 A through  44 E are formed integral to the optical bench  34  for Mounting the stationary mirrors thereon. 
     FIG. 17A is a top view of the light collecting mirror  33 . The collector mirror  33  attaches to a collector bracket  35  by means of a pair of integrally-formed pivot arms  31  with distal hubs  29 . The pivot arms  31  of collector mirror  33  snap fit into notches  30  formed in collector mirror bracket  35 , and hubs  29  maintain the pivotal seating. With additional reference to FIG. 6A, the beam directing surface  32  which is mounted to the collector mirror  33  must be aligned with the laser beam that is produced by the laser beam production module  39  during the manufacturing calibration process. Moreover, the collector mirror  33  must also be aligned for the efficient collection of returned light. The pivoting collector mirror  33  allows for easy and infinite adjustment of the collector mirror  33 , and thus the beam directing surface  32 , along the vertical direction during manufacturing. The snug fit between the bracket notches  30  and the pivot arms  31  of the mirror allows for an assembler to adjust the position of the mirror while preventing further unintentional movement of the mirror after the alignment is complete. 
     In an alternative embodiment, the collector mirror  33  is mounted for dual-axis adjustment. This is accomplished by mounting the collector mirror  33  in a rectangular mirror frame (not shown) with pivot points at top and bottom. The collector mirror frame itself has additional pivot arms on the sides for fitting into the notches  30  of mirror bracket  35  (similar to the pivot arms shown integral to mirror  33  in FIG.  17 A). This combination of pivot points both at the top and bottom of the mirror and on the sides of the mirror frame provides for adjustment of the mirror in both a right-to-left direction as well as the up-and-down direction provided for in the scanner embodiment detailed above. In both cases, the pivoting collector mirror  33  can be adjusted and calibrated at the factory. If desired, the pivot points of the collector mirror  33  can be fixed by gluing after calibration. 
     Referring to FIGS. 6A,  17  and  18 , at the opposite end of the optical bench  34  the laser beam module support bench  41  is formed at a height above the mirror bracket array  44 . This allows for mounting of the polygon  36  and rotating motor  37  below the laser beam production module  39 . The laser beam production module  39  is mounted in the laser module mount bracket  28 . The analog signal processing board  52  attaches to PC board bracket  54 , above and behind the laser module mount bracket  28 . The entire optical bench  34  is a single piece molded plastic unit, which holds all of the components that make up the omnidirectional laser scanning platform. 
     In the preferred embodiment of the invention the collector mirror  33 , beam directing surface  32 , laser beam production module  39  and photodetector  51  are mounted above the polygon  36  and mirror array  38 . However, it is within the scope of the invention to reverse the orientation of these components with respect to each other. 
     Having described the physical construction of the laser scanning platform of the present invention, it is appropriate at this juncture to describe the manner in which the laser scanning pattern is produced. A laser beam is produced from the laser beam production module  39  and is directed towards the beam directing surface  32  mounted on the light collector mirror  33 . The laser beam reflects from the beam directing surface  32  towards the mirrored facets on the rotating scanning polygon  36 . As the polygon spins, the incident laser beam reflects off the rotating mirrors  36 A through  36 D and sweeps the laser beam about its rotational axis along a plurality of different paths which intersect the stationary array of mirrors  38 A through  38 E on the optical bench  34 . During each revolution of the scanning polygon  36 , the laser beam reflects off the rotating mirrors and is repeatedly swept across the array of stationary mirrors thereby producing first, second, third, fourth and fifth groups of plural scan lines, respectively. Each scan line in each group of scan lines is substantially parallel to each other scan line in that group of scan lines. The intersection of the groups of parallel scan lines produces a highly collimated canning pattern. The scan lines that make up this highly collimated scanning pattern  13 , as shown in FIGS. 19 and 20, are projected out through the light transmission window and intersect about a projection axis that extends outward from the light transmission window  14  to produce a highly confined narrow scanning volume. Within this narrowly confined scanning volume a bar code symbol can be scanned omnidirectionally, while preventing unintentional scanning of code symbols on objects located outside of the scanning volume. 
     When a bar code symbol on an object is presented to the highly collimated scanning pattern  13  projected through a narrowly confined scanning volume the bar code symbol is scanned independent of its orientation in the scanning volume. At least a portion of the laser light reflected from the scanned code symbol is directed through the light transmission window  14 , reflected off the stationary array of mirrors  38 , reflected off the rotating polygon  36 , focused by the light collection mirror  33  onto the photodetector  51 , whereupon an electrical signal is produced for use in decode signal processing. 
     The omnidirectional laser scanning platform of the present invention can be automatically activated or can include manual activation means. Manual activation means can include a trigger or other switch located on the exterior of the scanner housing which when depressed activates the laser, the laser scanning mechanism, the photoreceiving circuitry and decoding circuitry. Laser bar code scanning systems employing manual activation means are well known in the art. Various embodiments of automatically-activated bar code symbol scanning systems are detailed in FIGS. 10,  10 A,  11  and  11 A. A number of the subsystems are common to all embodiments and are thus described in detail with respect to FIG. 10 only. However, the description of these subsystems applies similarly when they are included in the other listed embodiments. 
     As indicated in FIG. 10 an automatically activated bar code symbol scanning system of the first design is composed of a number of subsystems, an infrared (IR) based object detection subsystem  112  as taught in prior U.S. Pat. Nos. 5,260,553, 5,340,971 and 5,808,285, incorporated herein by reference; a scanning means  111 , a photoreceiving circuit  112 , analog-to-digital conversion circuit  113 , a bar code presence detection subsystem  114  as taught in prior U.S. Pat. Nos. 5,484,992 and 5,616,908 incorporated herein by reference, bar code scan range detection module  115 , symbol decoding module  116 , data format conversion module  117 , symbol character data storage unit  118 , and a data transmission circuit  119 . As illustrated, these components are operably associated with a programmable system controller  122  which provides a great degree of versatility in system control, capability and operation. 
     In accordance with the present invention, the purpose of the object detection subsystem is to perform the following primary functions during object detection: (i) automatically and synchronously transmitting and receiving pulse infrared (IR) signals within an IR-based object detection field; (ii) automatically detecting an object in at least a portion of the IR-based object field by analysis of the received IR pulse signals; and (iii) in response thereto, automatically generating a first control activation signal A 1  indicative of such automatic detection of the object within the object detection field. As shown in FIG. 10, the first control activation signal A 1  is provided to the system control subsystem  122  for detection, analysis and programmed response. 
     As illustrated in FIG. 10, the scanning circuit  111  includes, a light source  147  which is shown as a solid state visible laser diode (VLD), but can be any source of intense light suitably selected for maximizing the reflectivity from the object&#39;s surface bearing a bar code symbol, a scanning mechanism  150  such as a rotating polygon which is mounted on a rotating motor driven by motor drive  151 . 
     To selectively activate the laser light source  147  and scanning mechanism  150 , upon receiving control activation signal A 1 , the system controller provides laser diode enable signal E L  scanning mechanism enable signal E M  as input to driver circuits  148  and  151  respectively. When signals E L  and E M  are at a logical high level the VLD is activated and the beam is scanned through the light transmission aperture and across the scan field. 
     When an object such as a product bearing a bar code symbol is within the scan field at the time of scanning, the laser beam incident thereon will be reflected. This will produce a laser light return signal of variable intensity which represents a spatial variation of light reflectivity characteristic of the spaced apart pattern of bars comprising the bar code symbol. Photoreceiving circuit  112  is provided for the purpose of detecting at least a portion of laser light of variable intensity, which is reflected off the object and bar code symbol within the scan field. Upon detection of this scan data signal, photoreceiving circuit  112  produces an analog scan data signal D 1  indicative of the detected light intensity. Analog scan data signal D 1  is provided as input to A/D conversion circuit  113 . As is well known in the art, A/D conversion circuit  113  processes analog scan data signal D 1  to provide a digital scan data signal D 2  which resembles, in form, a pulse width modulated signal, where logical “1” signal levels represent spaces of the scanned bar code symbol and logical “0” signal levels represent bars of the scanned bar code symbol. A/D conversion circuit  113  can be realized by any conventional A/D chip. Digitized scan data signal D 2  is provided as input to bar code presence detection module  114  and symbol decoding module  116 . 
     The bar code presence detection module performs the following primary functions during bar code symbol detection: (i) automatically generating an omnidirectional visible laser scanning pattern within the bar code symbol detection field defined relative to the scanner housing, to enable scanning of a bar code symbol on the detected object; (ii) automatically processing scan data collected from the bar code symbol detection field and detecting the presence of the bar code symbol thereon; and (iii) automatically generating a control activation signal A 2 =1 indicative thereof in response to the automatic detection of the bar code symbol. As shown in FIG. 10, the second control activation signal A 2  is provided to the system controller  122  for detection, analysis and programmed response. 
     The purpose and function of the bar code presence detection module is to determine whether a bar code is present or absent from the scan field over a time interval specified by the system controller, by detecting a bar code symbol “envelop” from digital scan data signal D 2  by analyzing the digital count and sign data in the signal. When a bar code symbol “envelop” is detected in the scan field, and the bar code presence detection module provides signal A 2  to the system controller  122  which then causes the system to undergo a transition for the bar code presence detection state to the bar code reading state. 
     Within the context of the system design shown in FIG. 10, the bar code symbol decoding module  116  performs the following functions during the bar code symbol reading state: (i) automatically generating an omnidirectional visible laser scanning pattern within the scan field, to enable scanning of the detected bar code symbol therein; (ii) automatically decode-processing scan data collected from the scan field so as to detect the bar code symbol on the detected object;  30  (iii) automatically generating a third control activation signal A 3 =1 indicative of a successful decoding operation, and producing decoded symbol character data representative of the detected and read bar code symbol. As shown in FIG. 10, the third control activation signal A 3  is provided to the system controller  122  for detection, analysis and programmed response. 
     Upon receiving control activation signal A 3 , the system controller  122  generates and provides enable signals E FC , E DS , and E DT  to the data format conversion module  117 , data storage unit  118 , and data transmission circuit  119 , respectively at particular stages of its control program. Symbol decoding module  116  provides decoded symbol character data D 3  to data format module  117  to convert data D 3  into two differently formatted types of symbol character data, namely D 4  and D 5 . Format-converted symbol character data D 4  is of the “packed data” format, particularly adapted for efficient storage in the data storage unit  118 . Format-converted symbol character data D 5  is particularly adapted for data transmission to data collection and storage device, or a host device such as a computer or electronic cash register. When format converted data D 5  is to be transmitted to a host device, the system controller  122  will generate and provide enable signal E DT  to data transmission circuit  119 . Thereupon, data transmission circuit  119  transmits format-converted data D 5  to the data collection or host device via the data transmission lines of flexible connector cable  125 . 
     As shown in FIG. 10A a second embodiment of an automatically activated bar code symbol scanning system of a second design is composed of a number of subsystems as well, namely an IR-based object detection subsystem  82 ; a laser-based bar code symbol detection subsystem  83 ; a laser-based bar code symbol reading subsystem  84 ; a data transmission subsystem  85 ; a state indication subsystem  86 ; a data transmission activation switch or control device  87 A integrated with the scanner housing in part or whole; a mode-selection sensor  87 B integrated with the scanner housing in part or whole; and a system control subsystem  88  operably connected to the other subsystems described above. In general, system  79  has a number of preprogrammed operational states, namely: an object detection state; a bar code symbol detection state; a bar code symbol reading state; and a data transmission state. 
     Within the context of the system design shown in FIG. 10A, the IR-based object detection subsystem  82  performs the following primary functions during the object detection state: (i) automatically and synchronously transmitting and receiving pulse infrared (IR) signals within an IR-based object detection field  89  defined relative to the scanner housing  10 ; (ii) automatically detecting an object in a least a portion of the IR-based object detection field  89  by analysis of the received IR pulse signals; and (iii) in response thereto, automatically generating a first control activation signal A 1  indicative of such automatic detection of the object within the object detection field. As shown in FIG. 10A, the first control activation signal A 1 =1 is provided to the system control subsystem  88  for detection, analysis and programmed response. When control activation signal A 1 =1 is received by the system controller the bar code symbol reading device is caused to undergo a state transition from bar code symbol detection state to bar code symbol detection state. This transition has been described in detail in connection with the embodiment shown in FIG.  10 . 
     As shown in the figures hereof, object detection, bar code detection and bar code reading fields  89 ,  90  and  91 , respectively, have been schematically represented only general terms. For purposes of clarity, the specific characteristics of these fields have not been shown. Notably, however, such characteristics can be ascertained from the various references relating thereto which are identified and incorporated herein by reference. 
     Within the context of the system design shown in FIG. 10A, the laser-based bar code symbol detection subsystem  83  performs the following primary functions during the bar code symbol detection state: (i) automatically generating a visible laser scanning pattern of predetermined characteristics within the laser-based bar code (symbol) detection field  90 , defined relative to the scanner housing (not shown), to enable scanning of a bar code symbol on the detected object; (ii) automatically processing scan data collected from the bar code symbol detection field  89  and detecting the presence of the bar code symbol thereon; and (iii) automatically generating a control activation signal A 2 =1 indicative thereof in response to the automatic detection of the bar code symbol. As shown in FIG. 10A, the second control activation signal A 2  is provided to the system control subsystem  88  for detection, analysis and programmed response. When second control activation signal A 2  is provided to the system control subsystem  88 , this causes the bar code symbol reading device to undergo a state transition from bar code symbol detection state to bar code symbol reading state. This transition has also been described in detail in connection with FIG. 10 above. 
     Within the context of the system design shown in FIG. 10A, the laser-based bar code symbol reading subsystem  84  performs the following functions during the bar code symbol reading state: (i) automatically generating an omnidirectional visible laser scanning pattern within the laser-based bar code symbol reading field  91  defined relative to the scanner housing, to enable scanning of the detected bar code symbol therein; (ii) automatically decode-processing scan data collected from the bar code symbol reading field  91  so as to detect the bar code symbol on the detected object, (iii) automatically generating a third control activation signal A 3 =1 indicative of a successful decoding operation, and producing decoded symbol character data representative of the detected and read bar code symbol. As shown in FIG. 10A, the third control activation signal A 3  is provided to the system control subsystem  88  for detection, analysis and programmed response. The system control subsystem  88  responds as described above in relation to FIG. 10, whereby the data is decoded and formatted and sent to the data transmission subsystem  85 . 
     Within the context of the system design shown in FIG. 10A, the data transmission subsystem  85  during the data transmission state automatically transmits produced symbol character data to the bost system (to which the bar code reading device is connected) or to some other data storage and/or processing device, only when the system control subsystem  88  detects the following conditions: (1) generation of third control activation signal A 3 =1 within a predetermined time period, indicative that the bar code symbol has been read; and (ii) generation of data transmission control activation control signal A 4 =1 (e.g. produced from manually-actuatable switch  87 A) within a predetermined time frame, indicative that the user desires the produced bar code symbol character data to be transmitted to the host system or intended device. 
     Within the context of the system design shown in FIG. 10A, the state-selection sensor  87 B has two primary functions: (i) to automatically generate the fourth control activation signal A 4 =1 whenever the scanner housing has been placed on a countertop or like surface, so that the system is automatically induced into its automatic hands-free mode of operation; and (ii) to automatically generate the fourth control activation signal A 4 =0 whenever the scanner housing has been lifted off of a countertop or like surface, so that the system is automatically induced into its automatic hands-on mode of operation. In the automatic hands-free mode of operation, the state-selection sensor  87 B effectively overrides the data transmission switch  87 A. In the automatic hands-on mode of operation, the data transmission switch  87 A effectively overrides the state-selection sensor  87 B. 
     Within the context of the system design shown in FIG. 10A, the system control subsystem  88  performs the following primary functions: (i) automatically receiving control activation signals A 1 , A 2 , A 3  and A 4 ; (ii) automatically generating enable signals E 1 , E 2 , E 3 , and E 4 ; and (iii) automatically controlling the operation of the other subsystems in accordance with a system control program carried out by the system control subsystem  88  during the various modes of system operation. 
     FIGS. 11 and 11A illustrate an automatically-activated laser bar code scanning system wherein there is no object detection subsystem and the system is activated from the bar code presence detection state. The automatically-activated laser bar code scanning system concept is shown in related application Ser. No.  09 / 204 , 176  (the &#39;176 application being commonly owned by Metrologic Instruments, Inc. and incorporated herein by reference). As indicated in FIG. 11, the automatically-activated bar code symbol scanning platform of this third general system design  100  comprises a number of subsystems, namely: a laser-based bar code symbol detection subsystem  101 ; a laser-based bar code symbol reading subsystem  102 ; a data transmission subsystem  103 ; a state indication subsystem  104 ; a data transmission activation switch or control device  105 A integrated with the scanner housing (not shown) in part or whole; a mode-selection sensor  105 B integrated with the scanner housing in part or whole; and a system control subsystem  106  operably connected to the other subsystems described above. In general, the system  100  has a number of preprogrammed states of operation, namely: an object detection state; a bar code symbol detection state; a bar code symbol reading state; and a data transmission state. 
     Within the context of the system design shown in FIG. 11, the laser-based bar code symbol detection subsystem  101  performs the following primary functions during the bar code symbol detection state: (i) automatically generates a pulsed visible laser scanning pattern of predetermined characteristics within a laser-based bar code symbol detection field  107 , defined relative to the scanner housing, to enable the detection of a bar code symbol on an object located in the field  107 ; (ii) automatically processes scan data collected from the bar code symbol detection field  107  and detects the presence of the bar code symbol thereon; and (iii) automatically generates a control activation signal A 2 =1 indicative thereof in response to the automatic detection of the bar code symbol. As shown in FIG. 11, the second control activation signal A 2  is provided to the system control subsystem  106  for detection, analysis and programmed response. When second control activation signal A 2  is provided to the system control subsystem  88 , this causes the bar code symbol reading device to undergo a state transition from bar code symbol detection state to bar code symbol reading state. This transition has been previously described in detail in connection with FIG. 10 above. 
     Within the context of the system design shown in FIG. 11, the laser-based bar code symbol reading subsystem  102  performs the following functions during the bar code symbol reading state: (i) automatically generates a visible laser scanning pattern of predetermined characteristics within a laser-based bar code (symbol) reading field  108  defined relative to the scanner housing, to enable scanning of the detected bar code symbol therein; (ii) automatically decode-processes scan data collected from the bar code symbol reading field  108  so as to detect the bar code symbol on the detected object; (iii) automatically generates a third control activation signal A 3 =1 indicative of a successful decoding operation, and produces decoded symbol character data representative of the detected and read bar code symbol. As shown in FIG. 11, the third control activation signal A 3  is provided to the system control subsystem  106  for detection, analysis and programmed response. The system control subsystem  106  responds as described above in relation to FIG. 10, whereby the data is decoded and formatted and sent to the data transmission subsystem  103 . 
     Within the context of the system design shown in FIG. 11, the data transmission subsystem  103  during the Data Transmission State automatically transmits produced symbol character data to the host system (to which the bar code reading device is connected) or to some other data storage and/or processing device, only when the system control subsystem  106  detects the following conditions: (1) generation of third control activation signal A 3 =1 within a predetermined time period, indicative that the bar code symbol has been read; and (ii) generation of data transmission control activation signal A 4 =1 (e.g. produced from manually-actuatable switch  105 A) within a predetermined time frame, indicative that user desires the produced bar code symbol character data to be transmitted to the host system or intended device. 
     Within the context of the system design shown in FIG. 11, the state-selection sensor  105 B has two primary functions: (i) to automatically generate the fourth control activation signal A 4 =1 whenever the scanner housing has been placed on a countertop or like surface so that the system is automatically induced into an automatic hands-free mode of operation; and (ii) to automatically generate the fourth control activation signal A 4 =0 whenever the scanner housing has been lifted off of a countertop or like surface so that the system is automatically induced into an automatic hands-on mode of operation. In the automatic hands-free mode of operation, the mode-select sensor  105 B effectively overrides the data transmission switch  105 A. In the automatic hands-on mode of operation, the data transmission switch  105 A effectively overrides the mode-select sensor  105 B. 
     Within the context of the system design shown in FIG. 11, the system control subsystem  106  performs the following primary functions: (i) automatically receiving control activation signals A 2 , A 3  and A 4 ; (ii) automatically generating enable signals E 2 , E 3 , and E 4 ; and (iii) automatically controlling the operation of the other subsystems in accordance with a system control program carried out by the system control subsystem  106  during the various modes of system operation. 
     The fourth general system design of the automatically-activated bar code symbol scanning as shown in FIG. 11A, comprises a number of subsystems, namely: a laser-based bar code symbol detection subsystem  131 ; a laser-based bar code symbol reading subsystem  132 ; a data transmission subsystem  133 ; a state indication subsystem  134 ; and a system control subsystem  136  operably connected to the other subsystems described above. In general, the system  130  has a number of preprogrammed states of operation, namely: a bar code symbol detection state; a bar code symbol reading state; and a data transmission state. 
     Within the context of the system design shown in FIG. 11A, the laser-based bar code symbol detection subsystem  131  performs the following primary functions during the bar code symbol detection state: (i) automatically generates a pulsed visible laser scanning pattern of predetermined characteristics within a laser-based bar code symbol detection field  137 , defined relative to the scanner housing, to enable the detection of a bar code symbol on an object located in the field  137 ; (ii) automatically processes scan data collected from the bar code symbol detection field  137  and detects the presence of the bar code symbol thereon; and (iii) automatically generates a control activation signal A 2 =1 indicative thereof in response to the automatic detection of the bar code symbol. As shown in FIG. 11A, the second control activation signal A 2  is provided to the system control subsystem  136  for detection, analysis and programmed response. When second control activation signal A 2  is provided to the system control subsystem  136 , this causes the bar code symbol reading device to undergo a state transition from bar code symbol detection state to bar code symbol reading state. This transition has been described in detail in connection with FIG. 10 above. 
     Within the context of the system design shown in FIG. 11A, the laser-based bar code symbol reading subsystem  132  performs the following functions during the bar code symbol reading state: (i) automatically generates a visible laser scanning pattern of predetermined characteristics within a laser-based bar code (symbol) reading field  138  defined relative to the scanner housing, to enable scanning of the detected bar code symbol therein; (ii) automatically decode-processes scan data collected from the bar code symbol reading field  138  so as to detect the bar code symbol on the detected object; (iii) automatically generates a third control activation signal A 3 =1 indicative of a successful decoding operation, and produces decoded symbol character data representative of the detected and read bar code symbol. As shown in FIG. 11A, the third control activation signal A 3  is provided to the system control subsystem  136  for detection, analysis and programmed response. The system control subsystem  136  responds as described above in relation to FIG. 10, whereby the data is decoded and formatted and sent to the data transmission subsystem  133 . 
     Within the context of the system design shown in FIG. 11A, the data transmission subsystem  133  during the data transmission state automatically transmits produced symbol character data to the host system (to which the bar code reading device is connected) or to some other data storage and/or processing device, only when the system control subsystem  136  detects the generation of third control activation signal A 3 =1 within a predetermined time period, indicative that the bar code symbol has been read. 
     Within the context of the system design shown in FIG. 11A, the system control subsystem  136  performs the following primary functions: (i) automatically receiving control activation signals A 2 , A 3  and A 4 ; (ii) automatically generating enable signals E 2 , E 3 , and E 4 ; and (iii) automatically controlling the operation of the other subsystems in accordance with a system control program carried out by the system control subsystem  106  during the various modes of system operation. 
     Having now set forth the preferred embodiments and certain modifications of the concepts underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims.