Abstract:
A device, arrangement, and scanner are provided which are compact, reliable, and cost effective. The device is generally of the type in which a moving beam is scanned along a target object, and light reflected from the target object is detected and analyzed by the device. The device is preferably mirrorless. In addition, the device preferably lacks an integrated scanning component which imparts motion to the beam. In this regard, the device is provided with components for interacting with a separate adjacent scanning component, as well as a flexible connection device.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to methods and apparatus for electro-optically scanning and/or reading symbols. The present invention is further directed to scanners which are preferably mirror-less, and their use with and/or incorporation into existing devices, such as cell phones, pagers, personal data assistants (PDA&#39;s), and the like. 
   In scanning and reading systems known in the art, a light beam is directed by a lens or other optical components along the light path toward a target, such as a bar code symbol. The light source is typically a gas or semiconductor laser. The use of semiconductor devices as the light source is especially desirable because of their small size, low cost and low voltage requirements. The laser beam is optically modified, typically by an optical assembly, to form a beam spot of a certain size at the target distance. A moving-beam scanner operates by repetitively scanning the light beam in a line, pattern or series of lines across the target by means of imparting motion to the light beam through use of a scanning component. Such mechanisms frequently employ a mirror disposed in the optical path of the light beam. 
   Bar code reading systems also include a sensor or photo detector which detects light reflected or scattered from the target symbol. The photo detector or sensor is positioned in the scanner in an optical path so that it has a field of view which ensures the capture of a portion of the light which is reflected or scattered off the symbol. This light is detected and converted into an electrical signal. Electronic circuitry and software decode the electrical signal into a digital representation of the data represented by the symbol that has been scanned. For example, the analog electrical signal generated by the photo detector is converted by a digitizer into a pulse or modulated digitized signal, with the widths corresponding to the physical widths of the bars and spaces. Such a digitized signal is then decoded, based on the specific symbology used by the symbol, into a binary representation of the data encoded in the symbol, and subsequently to the information or alphanumeric characters so represented. 
   However, conventional moving-beam scanners and readers possess certain disadvantages. In some laser scanning applications, mirror movements have been found to be undesirable. 
   EP 0 731 417, the disclosure of which is incorporated herein by reference in its entirety, describes and number of embodiments and ways of generating a scanning beam. For instance, EP 0 731 417 discloses arrangements that include oscillating mirrors, oscillating substrates which include the scanning beam source, and arrays of light sources that are activated in a way that mimics a scanning beam. With regard to the embodiment of EP 0 731 417 that physically moves the laser light generator within the device, there is disclosed a laser light-generating diode disposed on a substrate, the substrate being mounted on rotatable hinges within a relatively stationary housing. 
   U.S. Pat. No. 5,144,120 to Krichever et al., the disclosure of which is incorporated herein by reference in its entirety, discloses mirrorless scanners with moveable laser, optical and sensor components. More particularly, Krichever et al. discloses scanning devices that include a drive means for repetitive movement about an axis or in a plane within the device to effect scanning. 
   Although the abovementioned documents embody important advances in the art, incorporation of a means for imparting motion to the light beam generator itself, or to reflecting mirrors, (i.e.—the “scanning component”) into the scanner/reader itself adds size, cost and complexity to the device. 
   Thus, there is a need for a more compact and versatile scanner which is simply and inexpensively fabricated. Moreover, there is a need for such a scanner that can be easily incorporated into or associated with other devices. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is an object of the present invention to provide a compact and versatile scanner/reader which is simply and inexpensively fabricated. 
   It is another object of the present invention to provide a scanner/reader which functions as a moving beam device, but does not have a scanning component per se, or a mirror, as an integrated part of the device. 
   It is a further object of the present invention to provide a scanner/reader with a construction which is versatile, compact and can be easily associated and utilized with other devices, such as cell phones, pagers, personal data assistants, etc. 
   According to one aspect, the present invention provides a device comprising: means for providing an oscillating magnetic field; a printed circuit board; a moving beam scanner, the scanner comprising: a substrate; a laser light source mounted to the substrate; at least one light receiving photodiode mounted to the substrate; a cap mounted over the substrate; a lens for focusing the laser light source onto a target; a lens for collecting light reflected from the target; means mounted to the scanner for interacting with the means for providing an oscillating magnetic field; at least one flexible connector mechanically and electrically coupling the scanner and the circuit board such that a range of oscillation between the scanner and the circuit board is possible; and wherein the scanner lacks a mirror and a scanning component. 
   According to a further aspect, the present invention provides, in combination, a moving-beam scanner and a scanning component for imparting motion to the beam: the scanner comprising: a substrate; a light source mounted to the substrate; at least one light-receiving photodiode mounted to the substrate; a cap mounted over the substrate; a lens for focusing the light source onto a target; a lens for collecting light reflected from the target; means mounted to the scanner for interacting with the scanning component; and wherein the scanning component is positioned adjacent to and outside the cap. 
   According to another aspect, the present invention provides a moving-beam scanner comprising: a light source; at least one light-receiving photodiode; lens means for focusing the light source onto a target and collecting light reflected from the target; housing means; and means associated with the scanner for interacting with a scanning component to impart motion to the beam while maintaining the light source, lens means, and housing means fixed relative to each other; wherein the housing means lacks a mirror. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an arrangement constructed according to the principles of the present invention; 
       FIG. 2  is a further perspective view of the arrangement of  FIG. 1 ; 
       FIG. 3  is a further perspective view similar to  FIG. 2  illustrating operation of the arrangement of the present invention; 
       FIG. 4  is a perspective view similar to  FIG. 3 ; 
       FIG. 5  is a perspective view of an alternative arrangement according to the principles of the present invention; and 
       FIG. 6  is a perspective view of a further arrangement consistent with the principles of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   A device  1  constructed according to the principles of the present invention is embodied in FIG.  1 . The term “device” is intended as a generic term which encompasses numerous assemblies and subassemblies of components for carrying out a particular function. By way of example, the device  1  could be a cell phone, pager, personal data assistant, or subassembly thereof. This list of devices is not exhaustive. It will be evident from the present description that the principles of the present invention could be successfully incorporated into other devices or subassemblies as well. 
   The arrangement depicted in  FIG. 1  generally includes a scanner or reader  10 . The term “scanner” and “reader” are intended to encompass a device which can at least receive a target reflection. The reflection image may then be converted to electrical signals which may be transferred to other devices, or further manipulated by the scanner  10  itself. For example, scanner  10  can be used to read a bar code which is such that the data contained therein is interpreted, as is known in any manner known to those of ordinary skill in the art. 
   In the embodiment depicted in  FIG. 1 , the scanner  10  is associated in combination with a scanning component  14 . The term “scanning component” is intended as a generic term representing a device which is capable of imparting motion or a “scanning” action to the scanner  10 . In the illustrated embodiment, the scanning component  14  comprises a means for providing an oscillating magnetic field, such as a vibration motor  16  which includes an oscillating magnet  18 . Such motors are frequently incorporated into devices such as cell phones and pagers as a means of alerting the user to incoming messages, without resorting to the use of audible signals. However, other devices are contemplated, so long as the requisite external oscillating magnetic field is produced. 
   Both the scanner  10  and the scanning component  14  are associated with a printed circuit board  12 , or similar component, of the device  1 . 
   Further details of a scanner formed consistent with the principles of the present invention are illustrated by reference to  FIGS. 2-5 . 
   The scanner  10  preferably includes a suitable substrate  20 . Substrate  20  can assume any suitable form which is mechanically and electrically suitable for connecting the scanner  10  and its various components to the device  1 , via the printed circuit board  12 . For instance, in certain embodiments substrate  20  can be in the form of a small printed circuit board having dimensions on the order of approximately 4 mm×4 mm. As readily apparent, scanner  10  is very small and compact in size. 
   As noted above, in order to provide a compact, yet reliable and cost effective scanner  10 , the present invention has been able to provide such a construction through various design features. For instance, it should be noted that scanner  10  does not include a mirror or reflective component which is used to reflect a light source onto a target image. By excluding a mirror or similar reflective component from the scanner  10 , allows a reduction in the overall size of the scanner  10 , as well as a less complex and more cost effective device. 
   According to the present invention, further advantages are obtained by constructing the scanner  10  such that the scanning component  14  is not integrated therewith. In other words, scanning component  14  is actually a separate component from the scanner  10 . However, scanner  10  is designed such that it interacts with scanning component  14  in a manner which provides or imparts the desired scanning motion to the light source of scanner  10 . The interaction means between scanner  10  and scanning component  14  may include mechanical means, magnetic means, or any other suitable arrangement. 
   Returning to the features of the scanner  10  per se, a light source  22  is mounted to the substrate  20 . Light source  22  can be any suitable light source. As noted above, a semiconductor laser is often a preferred light source. In this regard, light source  22  may comprise a VCSEL laser chip as described in EP 0 737 417. 
   The light source  22  produces a light beam which, in a state in which the scanner  10  is not being oscillated, i.e.—a state of rest, is substantially normal to a plane defined by a surface of the substrate  20 , and which is represented as Θ in FIG.  2 . 
   Scanner  10  is further provided with a mechanism for receiving reflections off a target. According to the embodiments depicted in  FIGS. 2-5 , this function may be provided by at least one light receiving detector. In certain embodiments, there is a plurality of light receiving detectors  24 ,  25 . These detectors may comprise photodiodes or a CCD device. 
   Scanner  10  is also provided with a housing means. In the illustrated embodiment, housing means comprises a cap member  26  which at least partially covers substrate  20 . The cap may be formed from any suitable material and may have any suitable shape. In the embodiments depicted in the drawing figures, the cap may be formed from a plastic material, and may be generally rectangular with an arcuate or domed top. 
   Scanner  10  is also provided with lens means which cooperate with the light source, as well as with light reflected from the target image in order to provide the desired optical functions of the scanner  10 . The lens means preferably comprises an arrangement of lenses to accomplish this. In the embodiments depicted in  FIGS. 2-5 , the lens means comprises a first focusing lens  28  which receives light from the light source  22  and transmits the light source to the target. The lens means may further comprise a collection lens  30 , which may comprise the domed top of the cap  26 , for collecting light reflected off the target. The collected light is then transmitted to the light receiving means or light receiving photodiodes  24 ,  25 . 
   The scanner  10  may further comprise means for interacting with the scanning component  14 . As previously noted, the means for interacting with the scanning component may comprise any suitable arrangement or connection. The arrangement or connection may be either mechanical-based, magnetic, or electro-magnetic. In the embodiments illustrated in  FIGS. 2-5 , the means for interacting with the scanning component comprises a magnet  32 . The magnet  32  can be mounted to the cap  26  as shown, or may alternatively be mounted to the substrate  20  or any other part of the scanner  10  such that it can effectively interact with the scanning component  14 . 
   During operation of the vibration motor  16 , magnet  18  rotates or oscillates. The movement of the magnet  18  interacts with the magnet  32  in a manner which excites the scanner  10 . An AC signal is sent to the motor  16  to drive the magnet  18  at the proper speed. In other words, the motor is driven in a manner which causes the magnet to rotate at a speed sufficient to reach the resonant frequency of the scanner  10  via magnet  32 . 
   The above-described interaction imparts an oscillatory movement to the scanner  10  as a whole. This movement in turn causes the light or beam emitted from the light source  22  to travel back and forth across a target. The movement of the beam emitted from the light source  22  is accomplished without the use of a mirror or similar reflective component, and without the necessity of incorporating or integrating a scanning component within the scanner  10  itself. 
   Moreover, the desired scanning motion is imparted to the scanning beam, with the assistance of flexible connections described in further detail below, while maintaining the light source  22 , focusing lens  28 , and housing or cap  26  fixed relative to each other. This construction is beneficial from the standpoints of compactness, simplicity, and avoiding aberrations which can result from shifting the lens relative to the light source. 
   The type and range of oscillation of the scanner  10  is determined based upon various factors. Such factors could include the size of the target, location of the target relative to the scanner  10 , as well as the distance normally present between the scanner  10  and the target. 
   For example, it has been determined that providing a scanner  10  with a range of oscillation, when measured relative to the beam Θ while at rest to be on the order of +/−20°. This range of oscillation is illustrated in  FIGS. 2-4  and most clearly shown in  FIGS. 3 and 4  as α and β, respectively. 
   The scanner  10  must be flexibly coupled to the device  1  via the printed circuit board or similar component  12 . The means for attaching the scanner  10  could encompass numerous mechanical and/or mechanical/electrical arrangements. In the embodiment illustrated in  FIG. 2 , the flexible connection  34  includes at least one flexible connector or hinge  36 . In the illustrated embodiment, there are a plurality of flexible connectors or hinges  36 . While the number of hinges can vary according to the principles of the present invention, it is possible to utilize five or six such connections  36 . The flexible members or hinges  36  are preferably fastened to the substrate  20  as well as the printed circuit board  12  of the device  1 . The hinges  36  can be connected in any suitable manner, such as adhesive, welding, or through the use of fasteners. Preferably, the hinges  36  also provide an electrical connection between the substrate  20  and the printed circuit board  12 . 
   Although the above-described embodiment has been described in connection with a device which already includes a vibration motor  16 , it is well within the scope of the present invention to incorporate a scanner  10  into a device which does not include such a motor. When seeking to incorporate scanner  10  in a device which lacks a vibration motor, or similar component, it is possible to associate the scanner  10  with a proper scanning component or means for imparting a scanning motion to the scanner  10 . Examples of such means include a conventional electromagnetic coil  37  or similar device, which is preferably external to the scanner  10  as shown in FIG.  6 . 
     FIG. 5  illustrates an alternative construction form according to the principles of the present invention. Like reference numerals have been utilized to identify those features in common with the embodiments depicted in  FIGS. 2-4 . In general, the scanner  10 ′ is constructed in the same manner previously described and includes the same components. An alternative arrangement for flexibly connecting the scanner  10  to the device  1  via printed circuit board  12 , or similar component, is illustrated generally as reference element  38 . The flexible connection  38  is generally in the form of a mechanical pivot. In the illustrated embodiment, the mechanical pivot comprises a rotatable shaft  40  which is mounted within bracket holders  42  for support. A flexible connector  44  is electrically and mechanically attached to the scanner  10 , preferably via the bottom of substrate  20 ′, as well as a printed circuit board or similar component of the device  1 . The flexible connector  44  can take any suitable form. In the illustrated embodiment, flexible connector  44  comprises a ribbon-type element. Through this flexible connection  38 , the scanner  10  is capable of oscillating in the desired manner, as previously described, when interacting in a proper way with a scanning component. 
   While the present invention has been described by reference to the above-mentioned embodiments, certain modifications and variations will be evident to those of ordinary skill in the art. Therefore, the present invention is limited only by the scope and spirit of the appended claims.