Abstract:
A unitary body of optical material and associated methods for reading indicia such as bar codes is provided. The unitary body can focus light from a light source into a beam, redirect light reflected from a target to a photodetector, and provide mechanical support for a light source, printed circuit board, or other indicia reader components. In comparison to conventional apparatus, the unitary body requires a reduced number of components and is therefore easier and less expensive to manufacture and assemble. The unitary design increases reliability and performance consistency while decreasing sensitivity to thermal and mechanical loading. Moreover, the unitary body reduces the overall tolerance budget of a reader and therefore facilitates mass production of optical apparatus and readers. The unitary body and associated methods may be implemented in a compact reader with the aforementioned advantages in the form of a pen, or can be integrated into an antenna of a wireless device, such as a cell phone or a PDA.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to apparatus and methods for reading optically encoded indicia such as bar codes. More particularly, this invention relates to optical systems that project laser light toward an optically encoded target, collect light reflected from the target, and use the reflected light to generate a readable electrical signal corresponding to the encoded target. 
     Conventionally, scanner or bar code reader optical systems require numerous optical components to control, project, and collect light. FIG. 1 illustrates some key components of a conventional laser light focusing device  1  that are commonly found in the prior art. Lens  2  and aperture  3  are used together to focus light from laser source  4 . Star washer  5  is used to hold lens  2  in place against the inner lip  6  of aperture  3 . 
     These individual parts must be produced and assembled within narrow manufacturing tolerances for a bar code reader to function properly. Additional components such as a laser source support and a collector for incoming light (not shown) further increase the difficulty and expense of producing a bar code reader. The large number of components combined with the need for assembly and inherent tolerance limits lead to large production costs and time requirements. Furthermore, the multi-component design leads to manufacturing flaws, decreased device longevity, sensitivity to thermal and mechanical loading, and inconsistent performance. Moreover, the multi-component design is ill-adapted for miniaturization. 
     Therefore, it would be desirable to provide apparatus and methods for reading indicia that require a reduced number of components, reduce the cost of manufacture and assembly, reduce manufacture and assembly time, increase reliability, decrease sensitivity to thermal and mechanical loading, and increase the consistency of performance. 
     It would also be desirable to provide apparatus and methods for reading indicia that reduce the overall tolerance budget of the reader and therefore facilitate mass production of optical apparatus and readers. 
     Moreover, it would be desirable to provide a compact indicia reader with the aforementioned advantages in the form of a pen. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide apparatus and methods for reading indicia that require a reduced number of components, reduce the cost of manufacture and assembly, reduce manufacture and assembly time, increase reliability, decrease sensitivity to thermal and mechanical loading, and increase the consistency of performance. 
     It is a further object of this invention to provide apparatus and methods for reading indicia that reduce the overall tolerance budget of the reader and therefore facilitate mass production of optical apparatus and readers. 
     It is a still further object of this invention to provide a compact reader with the aforementioned advantages in the form of a pen. 
     In accordance with the present invention, a unitary body is provided for controlling the profile of light and preferably laser light in an optical system that reads optically encoded indicia. The unitary body is preferably composed of optical material and includes an aperture forming area and a beam phase modifying area to form a beam for reading an optical code. In a preferred embodiment of the invention, an inner surface of the unitary body has an aperture forming outer region and a phase forming inner region. The unitary body also has an outer surface. In a preferred embodiment, the inner region of the inner surface and the inner region of the outer surface form a wavefront forming zone and everything outside the wavefront forming zone is an aperture forming zone. The embodiments of the unitary body produce a focus free system using a micro-aperture. In a particularly preferred embodiment, the outer surface of the unitary body is a beam splitter. 
     In one embodiment, the inner region of the inner surface is a converging region for focusing a portion of the light to form a beam and the outer region of the inner surface is a diverging region for diverging a portion of the light away from the beam. 
     In a preferred embodiment, the converging region is situated concentrically within the diverging region. The converging and diverging regions act together to form a beam that is directed through a surface in an output region of the unitary body to illuminate indicia. The outer surface of the unitary body which acts as a beam splitter, may further function as a collection surface that collects incoming reflected light. By splitting the beam, collection surface redirects a portion of the incoming light to a photodetector which generates an electrical signal indicative of light intensity for use in decoding an indicia such as a bar code. 
     In a particularly preferred embodiment, the unitary body includes a cavity adapted to accept and provide support for a laser source. The laser source is positioned optimally for providing light and for selective formation of a beam by the aforementioned converging and diverging regions. The unitary body may further include notches or studs for supporting circuit boards or associated components to provide support to the optical and mechanical components of the indicia reader. 
     In another particularly preferred embodiment of the invention, a unitary body is situated within a pen-shaped housing. This embodiment of the invention has the economical and mechanical benefits above and is an example of a hand held indicia scanner in accordance with the principles of the invention that is convenient to carry and use. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects and advantages of the invention will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which: 
     FIG. 1 is a cross-sectional view of a multi-component lens-aperture device representative of the prior art; 
     FIG. 2 is a perspective view of a preferred embodiment of a unitary body according to the present invention; 
     FIG. 3 is a schematic cross-sectional view of a portion of the unitary body of FIG. 2 illustrating some of the optical functions of the present invention; 
     FIG. 4 is a schematic cross-sectional view of a portion of the unitary body of FIG. 2 illustrating some of the additional optical functions of the present invention; 
     FIG. 5 is an illustrative example of a finite element simulation of an optical response of the unitary body of FIG. 2; 
     FIG. 6 is an illustrative example of a finite element simulation of additional optical responses of the unitary body of FIG. 2; 
     FIG. 7 is a cross-sectional view of a preferred embodiment of a unitary body like that of FIG. 2 situated in a pen-shaped housing; 
     FIG. 8 is a cross-sectional view of a preferred embodiment of a unitary body like that of FIG. 2 situated in pen-shaped housing and mechanically supporting a laser source and circuit elements; 
     FIG. 9 is a transverse cross-sectional view of an embodiment of a unitary body like that of FIG. 2 showing a tab to facilitate mounting in coordination with an aperture in a circuit board; 
     FIG. 10 is a cross-sectional view showing an embodiment of a unitary body similar to that of FIG. 2 mounted in a pen-shaped housing having a scanning element; and 
     FIG. 11 is a cross-sectional view showing an embodiment of a unitary body similar to that of FIG. 2 mounted in a pen-shaped housing having an adjustable focusing lens. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention includes a unitary body for use in an optical system, such as an optical code reader and in particular for reading and decoding encoded bar code indicia. The unitary body focuses light from a laser source into a laser beam. The unitary body has an aperture forming area which in one embodiment includes a diverging region of an inner surface of the unitary body to diverge a portion of the laser light away from the beam and has a beam phase modifying area which in one embodiment includes a converging region of the inner surface of the unitary body. In a preferred embodiment the converging region may be located concentrically within the diverging region. Thus configured, the converging and diverging regions act to selectively form a beam from the laser source by focusing a portion of the laser light into a beam and refracting peripheral light away from the beam to increase sharpness. The unitary body may be used in a variety of code readers including, but not limited to, scanners, wands, and pointers. 
     In one embodiment, light entering the unitary body, is formed into a beam by the converging and diverging regions and exits the unitary body through an output surface that is preferably perpendicular to the beam. The perpendicularity of the output surface allows the beam to pass straight through the output surface largely without refraction. The laser beam is directed at an encoded indicia, bar code, or other encoded target, and light is reflected back to the bar code reading unit. The unitary body has a collection surface, preferably adjacent the output surface, that collects the reflected light. 
     Preferably, the collection surface is at an oblique angle relative to the propagation direction of the incoming reflected light signal. The oblique angle allows the collection surface to redirect the reflected light to a photodetector that transduces the reflected light into an electrical signal indicative of the intensity of the reflected light. The photodetector outputs the electrical signal to signal processing circuit. 
     Incoming reflected light may be resolved into vector components parallel to and perpendicular to the plane of incidence defined by the beam of incoming light and the beam reflected from the collection surface. The parallel component is denoted as P polarization and the perpendicular component as S polarization. In a preferred embodiment, the oblique angle of the collection surface is chosen such that the collection surface preferentially redirects S-polarized incoming reflected light to the photodetector. Accordingly, the collection surface may therefore be considered a polarizing surface. However, it is not necessary that the collection surface be polarizing. 
     P-polarized incoming reflected light is preferentially transmitted through the collection surface and into the interior of the unitary body itself. The energy contained in the reflected S-polarized light is sufficient for a photodetector to generate an electrical signal indicative of the optically encoded target. In a preferred embodiment, the oblique angle of the collection surface is the Brewster&#39;s angle corresponding to the index of refraction of the unitary body. 
     Since a portion of the reflected light is transmitted through the unitary body and a portion is reflected, the collection surface of this embodiment is referred to as a Brewster&#39;s angle beam splitter. 
     It will be appreciated that in an embodiment of the invention in which the unitary body is contained in a housing, for example, a pen-shaped housing may be held in the hand of a user, there is a need to minimize the size of components and arrange them in a space-efficient manner. In such an embodiment, it may be necessary to position the collection surface at an angle with respect to incoming reflected light that is different from the Brewster&#39;s angle in order to reduce the space occupied by the collection surface. Even at angles greater than the Brewster&#39;s angle (as measured between collection surface and propagation direction of incoming light), sufficient S-polarized reflected light can be redirected to the photodetector to enable the encoded indicia to be read. 
     In another preferred embodiment, the output surface is recessed in the unitary body within the collection surface. According to this embodiment, laser light is emitted from the laser source, formed into a beam by the aperture forming area and the beam phase modifying area of the unitary body in the form of converging and diverging regions, and passed through the output surface. Stray or divergent light energy that diverges moderately from the beam will therefore fall outside the output surface onto the side of the collection surface internal to the unitary body. Because the collection surface is positioned at an oblique angle with respect to the transmitted laser beam, at least a portion of the divergent light incident on the internal side of the collection surface will be reflected away from the beam and thus trim the edge of the laser beam as it passes through the output surface. If the collection surface is positioned at a sufficiently high angle with respect to the angle of incidence of the moderately stray light, it will be completely reflected by the phenomenon of total internal reflection. The angle of the collection surface should be chosen to optimize the reflection of S-polarized light on the external surface of the unitary body. This angle is sufficient in most cases to give rise to total internal reflection of stray light energy on the surface internal to the unitary body. 
     It will be appreciated that although the unitary body is shown by way of example in various embodiment in the figures, that other configurations and combinations of functions achieved by the surfaces thereof are possible. For example, while the inner surface is used in one embodiment to effect aperture forming and phase modifying, these functions can be carried out by regions of the outer surface in whole or in part and in combination with regions of the inner surface. Moreover, while the inner regions of the surfaces of the unitary body have been used for beam phase modifying, it is understood that this function could be carried out by one of both of the outer regions or combinations of the inner and outer regions. The same is true for the aperture forming area which can include one or both of the inner regions or combinations of the inner and outer regions. Additionally, while the functions have been achieved by the use of converging and diverging regions, other optical elements can be implemented on the surfaces of the unitary body and/or by the shape of the unitary body to achieve the same functions. 
     The unitary body is preferably formed by injection molding of translucent material such as acrylic, but other molding processes and materials may also be used. It is therefore ideally suited to perform mechanical functions in addition to optical functions. In one embodiment, the unitary body may be provided with a cavity, the interior and walls of which may be used to support a laser source. Because optical systems with which the invention is designed to be used are usually controlled electronically, printed circuit boards are commonly used to provide the circuitry necessary to control such functions as the power distribution, signal processing, and data communication between the system components. In some embodiments, therefore, the unitary body may be provided with at least one notch, boss, or stud to support the edge of such a circuit board. 
     Some benefits of this configuration are that the unitary design permits a relatively easy combination of optical and mechanical features, is inexpensive to produce, and makes optimal use of available space. The uniformity of material used in the unitary design also reduces inter-component stresses that arise from thermal and mechanical loads even under normal-use conditions. In particular, the unitary design provides for the focusing of laser light into a beam, the adjustment of the beam profile or shape, and the collection and redirection of light reflected from a target. It also aids in the mechanical support of a laser source, circuit board, and/or other optical or electronic components of the associated system for reading signals from encoded indicia. The unitary design minimizes assembly costs and reduces the likelihood of failure or breakage. For example, the compactness of the unitary body enables a bar code reader to be placed in a housing in the form of a pen. The housing may also contain the photodetector, laser source, circuit boards, and auxiliary mechanical, optical, and electrical components. 
     Preferred embodiments of the apparatus and method of the invention will now be described with reference to FIGS. 2-11. 
     FIG. 2 is a perspective view of unitary body  21  showing circuit board notch  22 , laser support region  23 , laser beam focusing region  24 , output region  25 , aperture  26 , and collection surface  27 . A laser source may be housed within the cavity of laser support region  23 . A cavity within laser beam focusing region  24  may further accommodate the laser source. Notch  22  may be used to support a circuit board or provide a base for supporting components that control and provide power to the laser source, photodetector, and signal processing circuitry. 
     FIG. 3 shows laser source  30  situated within laser beam focusing region  24 . It will be understood that while laser source  30  may be located within laser beam focusing region  24 , it may be supported by a mount that is supported at least in part by support region  23  (FIG.  2 ). Laser source  30  emits light in the cavity of focusing region  24 . In a preferred embodiment, the converging region of the inner surface of the unitary body is a convergent lens  32  which converges a portion of light from laser source  30  into a transmitted beam, illustrated by rays  35 . In the preferred embodiment, the diverging region of the inner surface of the unitary body is a divergent lens  31 , disposed concentrically around convergent lens  32  in this embodiment, which removes diverging light  36  from transmitted beam  35  to increase the definition of transmitted beam  35 . This decreases optical scatter as beam  35  passes through output surface  33 , on its way to a target indicia. 
     Transmitted beam  35  passes substantially straight through output surface  33  because surface  33  is oriented perpendicular to transmitted beam  35 . In principle, there should be no refractive bending of transmitted beam  35 . Divergent light  36 , including light passing through diverging lens  31 , refracts into the volume of unitary body  21 . To enhance the signal-to-noise ratio of the reader, it is desirable to prevent divergent light  36  from reaching a photodetector  37  and interfering with the detection of reflected light  40  containing target information. This is accomplished at least in part by allowing divergent light to strike the interior side of collection surface  27  and be reflected back into the volume of unitary body  21 . 
     In particular, when angle A (FIG. 3) between divergent light  36  and the interior side of collection surface  27  is smaller than a critical value determined by the index of refraction of the unitary body, substantially all of divergent light  36  will be reflected and almost none will be transmitted through collection surface  27 . Because output surface  33  is situated substantially concentrically within collection surface  27 , the internal reflection of divergent light  36  by the internal side of collection surface  27  functions as an annular mask surrounding transmitted beam  35  and complements the function of divergent lens  31  by eliminating diverging light  36  from the periphery of transmitted beam  35 . 
     FIG. 4 shows collection surface  27  redirecting a reflected light, illustrated by rays  40 , to the photodetector  37 . Reflected light  40  is returned to unitary body  21  from an encoded indicia such as a bar code label and is partially reflected by collection surface  27  after passing through a window, lens, filter, or any combination of such elements (FIG. 7, for example). Reflected light  40  has a specular component and a diffuse component. The specular component is polarized substantially identically to transmitted beam  35 . The diffuse component is unpolarized, but resolvable into a first component, S, that is normal to a plane of incidence through collection surface  27  (e.g., a plane coincident with the plane of FIG. 3) and a second component, P, that is parallel to the incidence plane. 
     Collection surface  27  may reflect more S-polarized light  42  than P-polarized light and transmit more P-polarized light  43  than S-polarized light. In particular, angle B, between collection surface  27  and reflected light  41  can be chosen to transmit substantially all of the P-polarized component  43  of reflected light  41 , thus maximizing the proportion of the total light redirected to photodetector  37  that is composed of the S-polarized component  42 . Alternatively, angle B may be chosen so that collection surface  27  reflects substantially equivalent quantities of P-polarized and S-polarized light and is thus substantially non-polarizing. 
     It should be noted that specular light included in reflected light  40  is likely to saturate photodetector  37  because the laser source  30  emits P-polarized light. The polarization state is not altered by a reflective target in specular reflection. Therefore, the specularly reflected light returns to collection surface  27  in the P-polarized state and passes through collection surface  27 . S-polarized component  42  of reflected light  40  is sufficient to allow photodetector  37  to generate an electrical signal indicative of the strength of S-polarized component  42  and, thus, of reflected light  40 . 
     FIG. 5 shows a portion of a simplified finite element simulation of the invention. The reference numerals in FIGS. 5-9 have three digits, the last two of which indicate a correspondence with like elements in FIGS. 1-4. For example, element  521  of FIG. 5 corresponds to element  21  of FIG. 3, etc. In FIG. 5, laser source  530 , situated within laser beam focusing region  524 , emits laser light that is directed to output region  525  by focusing region  524 . It will be understood that the finite element model is presented as an illustration and that converging lens  32  and diverging lens  31  were not included in the model for the sake of simplicity. In output region  525 , diverging light  536  is prevented from passing through collection surface  527  by internal reflection, but beam  535  passes through output surface  533  (superimposed on model results for illustrative purposes). 
     FIG. 6 is a portion of a solution of a finite element simulation, similar to that of FIG. 5, showing the splitting of incoming reflected light  640  by collection surface  627 . P-polarized component  643  is transmitted through collection surface  627  while S-polarized component  642  of reflected light  640  is partially reflected (in the model, “PARTIAL” reflection is not illustrated for the sake of simplicity). 
     FIG. 7, a partial view of the apparatus of FIG. 8, shows a preferred embodiment in which unitary body  721  is mounted in a pen-shaped housing  700  that may be part of a wand used for reading indicia. Outer cylindrical surface  770  of laser beam focusing region  724  is press fit into bushing  780  inside housing  700 . Output region  726  of unitary body  721  is thus positioned within cavity  785  of housing  700 . Annular face  775  of laser support region  723  abuts bushing  780  and helps position unitary body  721  longitudinally within housing  700 . 
     Output region  725  includes collection surface  727  and output surface  726  which correspond to their above-described counterparts. Collection surface  727  is oriented to redirect S-polarized reflected light, entering through aperture  795  and passing through filter  750 , to photodetector  737 . Photodetector  737  is mounted on portions  760  of a printed circuit board having aperture  755  to allow photodetector  737  to receive light from collection surface  727 . The walls of the circuit board block stray light which otherwise may be directed onto a photodetector at an angle. Alternatively, an optical filter may take the place of aperture  755  or may be mounted above circuit board portions  760  for filtering the optical input to photodetector  737 . 
     FIG. 8 shows an embodiment of a unitary body  821  similar to that of FIG. 7, but having stud  856  for supporting circuit board  850 . FIG. 8 also shows a more complete view of a housing and its contents than does FIG.  7 . FIG. 8 shows laser source  830  mounted within laser beam focusing region  824 . As above, unitary body  821  may be press fit within pen shaped housing  800  using the outer cylindrical surfaces of support region  823  and laser beam focusing region  824 . Annular surface  875  of support region  823  abuts a ledge on an end of bushing  880  to help position unitary body  821  longitudinally with housing  800 . 
     Output region  825  is thus positioned within cavity  885  of housing  800  to transmit light from laser source  830  through output surface  826  after the light passes through focusing region  824 . The light then passes through window/filter  850 , and out of the housing through aperture  895 . Output region  825  includes a collection surface  827  for redirecting S-polarized incoming reflected light to photodetector  837 . Aperture  855  in portion  860  of circuit board  852  provides the necessary exposure of photodetector  837  to light from collection surface  827 . 
     Stud  856  may protrude longitudinally from base  857  of support region  823  (e.g., at location on annular base  857  outside the plane of the figure) and supports printed circuit board  850 . Support structures  854  support printed circuit board  852  and further support board  850 . Laser support region  823  and laser beam focusing region  824  may pass through a hole in printed circuit board  852  to conserve space inside housing  800  and to further support circuit board  852 . 
     FIG. 9 shows a transverse cross-section of an embodiment of unitary body  921  having rectangular cutouts  958  and  959  that form tab portion  962  of unitary body  921 . Tab portion  960  may be inserted through a corresponding slot or cut-out in a printed circuit board such as  852  as shown in FIG.  8  and discussed above. As before, unitary body  921  includes collection surface  927 , aperture  926 , output region  925 , and laser beam focusing region  924 . 
     FIG. 10 shows unitary body  1021  mounted in-pen shaped housing  1000  and employed in coordination with scanning element  1060 . The combination of unitary body  1021 , pen-shaped housing  1000 , and scanning element  1060  may be used to form a part of a scanning reader with a pen form factor. Laser source  1030  is mounted in laser support region  1023 . Laser diode legs  1054  are soldered directly to circuit board  1050 . Laser light emitted from laser source  1030  passes through laser beam focusing region  1024 , and exits unitary body  1021  through output region  1025 . (In this embodiment, output region  1025  does not require an oblique collection surface.) The emerging laser beam is then reflected by mirror  1070  toward mirror  1062 . Mirror  1062  redirects the laser beam out through the exit window  1095  in dome  1093 , thus allowing the beam to be directed at an encoded indicia. Exit window  1095  may contain filtering or focusing elements. Mirror  1070  is supported by cantilevered arm  1072 . 
     In certain embodiments surface  1073  of cantilevered arm  1072  may function as a light collector, such as a parabolic collector, for directing signal light toward photodetector. 
     In FIG. 10, mirror  1062  is mounted on lens  1064 . Lens  1064  may be of a variety of types of lenses including, but not limited to, a Fresnel lens or conventional lens. Lens  1064  further supports magnet  1066 . Pins  1067 , preferably comprising a polyester material (such as that sold under the trademark MYLAR7, by E. I. du Pont de Nemours &amp; Company), affix mirror  1062  and magnet  1066  to lens  104 . Lens  1064  is fixed to resilient support  1061  by clamp  1063 . Resilient support  1061  is preferably a spring support that at rest is in the position shown in FIG.  10 . Spring support  1061  is fixedly attached within housing  1000 , for example, to housing  1069  of coil  1068 . 
     When current is provided to coil  1068 , shown in cross-section in FIG. 10, magnet  1066  is caused to exert torque on resilient support  1061  and draw lens  1064  and mirror  1062  toward coil  1068  in the direction of arrow A. Bulge  1065  in dome  1093  enables lens  1064  to deflect to the extent required for scanning purposes without interference from housing  1000  while reducing the overall dimensions of housing  1000 . 
     If a time-varying current is supplied to coil  1068 , the position of mirror  1062  will oscillate and mirror  1062  will function as a scan mirror. Thus light from laser  1030 , directed toward mirror  1062  by mirror  1070 , may be used to produce a laser beam that oscillates with respect to pen-shaped housing  1000  and sweeps or scans across an indicia even when pen-shaped housing  1000  is stationary. 
     The indicia is decoded by collecting light reflected from the indicia. Reflected light passes through exit window  1095  and is focused by lens  1064  onto photodiode  1037  after passing through filter  1055 . Photodiode  1037  and filter  1055  may be disposed concentrically within coil  1068  as shown. Filtering elements may additionally or alternatively be incorporated into lens  1064  or may be mounted forward (on the dome side) of coil  1068 . 
     FIG. 11 schematically shows unitary body  1121  mounted in the pen-shaped housing  1100  of a pointer code reader. Unitary body  1121  supports laser source  1130 . Laser source  1130  emits laser light that passes through aperture  1162  in collection lens  1164 . Light, as illustrated by paths  1132 , then passes through lens  1124 . Lens  1124  focuses the light on focal plane P 2  as illustrated by paths  1134 . Lens  1124  is illustrated in FIG. 11 in a first position for a long focal length. Lens  1124  is supported by lens support  1226 . Lens  1124 , lens support  1126 , and slide switch  1128  together form lens assembly  1120 . By moving sliding switch  1128  along slideway  1129 , lens assembly  1120  can be repositioned relative to laser source  1130  in order to focus light from laser source  1130  at different focal planes. For example, paths  1134  show light converging at focal plane P 2  when lens assembly  1120  is positioned at position A in FIG.  11  and paths  1136  show light converging at focal plane P 1  when lens assembly is positioned at position B. For all settings of lens assembly  1120 , light passes through exit window  1150 . Exit window  1150  may include filtering and focusing elements and may be positioned at an oblique angle, as are corresponding windows in embodiment discussed above. 
     Light from the pointer scanner is manually directed at indicia to decode the indicia. Light is reflected from the indicia (e.g., along paths  1135 ), collected by collector lens  1164 , and redirected to photodetector  1137  (e.g., along paths  1139 ). Collector lens  1164  may also include light filtering elements. In the embodiment illustrated in FIG. 11, collector lens  1164  is an annular lens and laser source  1130  is located substantially along a central axis (not shown) of collector lens  1164 . It will be understood that this configuration uses space economically and enables the pointer scanner to fit into a small pen-shaped housing such as housing  1100 , but other configurations are also within the scope of the invention. 
     The code readers described above are preferably portable and may be provided with either rechargeable or disposable batteries for providing power to the laser source, control system, signal processing system, user interface components (e.g., LED&#39;s for mode, power, and battery charge indication), and data input and output functions. Input and output may be wireless or wire-based. For example, input and output may be accomplished using an RF or infrared transmitter or transceiver. Code readers according to the invention may be further configured for interfacing with cellular telephones or personal data assistants. A code reader may be provided with its own antenna, for wireless communication such as a cellular phone antenna, for RF communication. Alternatively or additionally, readers may be configured for data transmission by LED, laser, or cable. 
     Because the present invention enables placing all the components of the bar code reader into a confined space having cylindrical configuration, in another preferred embodiment a wand reader can be built into a cylindrical antenna of a wireless device such as a cell phone, or a PDA (Portable Data Assistant) also known as a personal digital assistant. The tip of the antenna would house at least the light source, multipurpose lens holder and the photodetector. The detector circuitry could either be located within the antenna or inside the actual housing of the device. The rest of the wand processing circuitry would be integrated inside the device housing. To read a bar code, a user would position the antenna tip over the bar code, enable a scan function in the device and move the tip across the bar code in order for the detector to receive optical information from the illuminated bar code. 
     Additionally, code readers may be configured for communication with a host, a network, and network access points and may be compatible with a variety of communication protocols, including, but not limited to, spread spectrum frequency hopping systems. 
     Thus it is seen that apparatus and methods for reading bar codes that require a reduced number of components, reduce the cost of manufacture and assembly, reduce manufacture and assembly time, increase reliability, increase the consistency of performance, and facilitate mass production of optical apparatus and bar code readers are provided. An optical device for compact bar code reader in the form of a pen is also provided. One skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation.