EP2151121A2

EP2151121A2 - Image reading system

Info

Publication number: EP2151121A2
Application number: EP08756516A
Authority: EP
Inventors: Timothy R. Fitch; Donna M. Fletcher; Colleen P. Gannon; Melvin D. Mccall; Mark A. Mcclaude; James F. O'donnell
Original assignee: Hand Held Products Inc
Current assignee: Hand Held Products Inc
Priority date: 2007-05-30
Filing date: 2008-05-30
Publication date: 2010-02-10
Also published as: WO2008151014A3; WO2008151014A2; EP2151121A4

Abstract

An imaging system for imaging a target comprising: an image reader having a field of view for imaging a target, the image reader having a housing with an inclined indentation; a stand adapted for holding the image reader a distance from the target, the stand having an inclined hook; a positioning apparatus for positioning the target within the field of view; wherein the inclined hook mates with the inclined indentation to hold the image reader and the image reader is removable from the stand in order that the image reader may image targets not placed in the positioning apparatus.

Description

IMAGE READING SYSTEM

RELATED APPLICATIONS

This application claims the priority date of U.S. Provisional Application serial number 60/932,270 filed 05/30/2007 entitled INDICIA READING SYSTEM".

FIELD

The present application relates to image reading devices, and more particuiarly to an image reading system for reading large volume information.

BACKGROUND

Image reading devices (also referred to as imagers, scanners, readers, optical readers, etc.) may be adapted to take a digital image or read data represented by printed information bearing indicia, (also referred to as symbols, symbology, bar codes, etc.) Image reading devices may be configured to read or obtain information from an information bearing device, such as an optical reader having an image sensor, a card having a magnetic strip, information bearing indicia such as a bar code, an RFID instrument, biogenic information such as a fingerprint, etc.

One type of symbol indicia is an array of rectangular bars and spaces that are arranged in a specific way to represent elements of data in machine readable form. Image reading devices typically transmit light onto a symbol and receive light scattered and/ or reflected back from an information bearing indicia (IBI). The received light is interpreted by an image processor to extract the data represented by the symbol. One-dimensiona! (1 D) image readers are characterized by reading data that is encoded along a single axis, in the widths of bars and spaces, so that such symbols can be read from a single scan along that axis, provided that the symbol is imaged with a sufficiently high resolution along that axis.

in order to allow the encoding of larger amounts of data in a single bar code symbol, a number of 1 D stacked bar code symbologies have been developed which partition encoded data into multiple rows, each including a respective 1 D bar code pattern, all or most all of which must be scanned and decoded, then linked together to form a complete message. Scanning still requires relatively higher resolution in one dimension only, but multiple linear scans are needed to read the whole symbol.

A class of bar code symbologies known as two dimensional (2D) matrix symbologies have been developed which offer orientation-free scanning and greater data densities and capacities thani D symbologies. 2D matrix codes encode data as dark or light data elements within a regular polygonal matrix, accompanied by graphical finder, orientation and reference structures. Often times an image reader may be portable and wireless in nature thereby providing added flexibility. In these circumstances, such readers form part of a wireless network in which data collected within the terminals is communicated to a host computer situated on a hardwired backbone via a wireless link. For example, the readers may include a radio or optical transceiver for communicating with a network computer.

Conventionally, a reader, whether portable or otherwise, may include a central processor which directly controls the operations of the various electrical components housed within the image reader. For example, the central processor controls detection of keyboard entries, display features, wireless communication functions, trigger detection, and IBI read and decode functionality. Efforts regarding such systems have led to continuing developments to improve their versatility, practicality and efficiency.

BRIEF DESCPJPTSON OF THE DRAWINGS

FIG. 1 is a fragmentary partially cutaway side view of an exemplary reader.

FIG. 2 is a block schematic diagram of an exemplary image reader.

FIG. 3 illustrates a schematic representation of an exemplary image reader system.

FIG. s 4a-4c illustrate three views of an exemplary image reader system.

FIG. s 5a-5e illustrate five views of an exemplary image reader system.

FIG. 6 illustrates exploded views of an exemplary image reader.

FIG. s 7a-7h illustrate eight views of an exemplary image reader system stand base.

FIG. 8 illustrates three views of an exemplary image reader system stand base.

DETAILED DESCRIPTION

Reference will now be made to exemplary embodiments which are illustrated in the accompanying drawings which may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these representative embodiments are described in detail so that this disclosure will be thorough and complete, and will fully convey the scope, structure, operation, functionality, and potential of applicability to those skilled in the art. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. The term "scan" or "scanning" use herein refers to reading or extracting data from a symbol or information bearing indicia (IBI). The term imaging may mean taking a digital picture.

Referring to the Figures, an exemplary image reader 112 which may have a number of subsystems for capturing and reading images, some of which may have symbol indicia provided therein. Reader 112 may have an imaging reader assembly 114 (including an image sensor 154) provided within a head portion or housing 116 which may be configured to be hand held by a handle portion 113. A trigger 115 may be used to control operation of the reader 112. The head portion 116 may have a medial plane MP selected so that when the hand-held imager is held with the head portion generally in a horizontal plane, the medial plane MP will generally be perpendicular to the face of the scanning head 116. Generally operators have a tendency to hold the medial plane of the head portion of the imager approximately normal to the plane of the target when collecting data. Image reader assembly 114 has imaging reader imaging optics having an optical axis (OA) for receiving light reflected off of a target T. The optical axis is a line of symmetry through the imaging optics. The target may be any object or substrate which may bear a 1 D or 2D bar code symbol or text or other machine readable IBI.

A trigger 115 may be used for controlling full or partial operation of the reader 1 12. Imaging reader assembly 114 may also have an aiming generator light source 132, aiming aperture 133, aiming optics 136, an illumination source 146, illumination optics 148 and imaging optics 152.

Illumination and aiming light sources with different colors may be employed. For example, in one such embodiment the image reader may include white and red LEDs, red and green LEDs, white, red, and green LEDs, or some other combination chosen in response to, for example, the color of the symbols most commonly imaged by the image reader. Different colored LEDs may be each alternatively pulsed at a level in accordance with an overall power budget.

An exemplary imaging system 110 may include a reader 112 in communication with a host processor 118. This host processor may be in communication with a network 120 which may be connected to one or more network computers 124. Reader 112 may include a number of components, such as an aiming pattern generator 130 adapted to generate an aiming pattern for assisting an operator to align target T coincident with the field of view of an imaging subassembly 150.

Aiming pattern generator 130 may include a power supply 131 , light source 132, aperture 133 and optics 136 to create an aiming light pattern projected on or near the target which spans a portion of the receive optical system 150 operational field of view with the intent of assisting the operator to properly aim the scanner at the IBI pattern that is to be read. A number of representative generated aiming patterns are possible and not limited to any particular pattern or type of pattern, such as any combination of rectilinear, linear, circular, elliptical, etc. figures, whether continuous or discontinuous, i.e., defined by sets of discrete dots, dashes and the like.

Generally, the aiming light source(s) 132 may comprise any light source to provide a desired illumination pattern at the target and may be one or more LEDs 134, such as part number NSPG300A made by Nichia Corporation.

The light beam from the LEDs 132 may be directed towards an aperture 133 located in close proximity to the LEDs. An image of this back illuminated aperture 133 may then be projected out towards the target location with a lens 136 Lens 136 may be a spherically symmetric lens, an aspheric lens, a cylindrical lens or an anamorphic Sens with two different radii of curvature on their orthogonal lens axis.

Alternately, the aimer pattern generator may be a laser pattern generator. The light sources 132 may also be comprised of one or more laser diodes such as those available from Rohm. In this case a laser coSlϊmation lens (not shown) will focus the laser light to a spot generally forward of the reader and approximately at the plane of the target T. This beam may then be imaged through a diffractive interference pattern generating element, such as a holographic element fabricated with a desired pattern. Examples of these types of elements may be available for example, from Digital Optics Corp. of Charlotte, N. C. among others. Elements of these types are described in U.S. Pat. numbers 4,895,790 (Swanson); 5,170,269 (Lin et al) and 5,202,775 (Feldman et al), which are hereby incorporated herein by reference-

Image reader may include an illumination assembly 142 for illuminating target area T. Illumination assembly 142 may also include one or more power supplies 144, illumination sources 146 and illumination optics 148.

Image sensor 154 may be a two dimensional array of pixels adapted to operate in a global shutter or full frame operating mode which is a color or monochrome 2D CCD, CMOS, NMOS, PMOS, CID, CMD, etc. solid state image sensor. This sensor contains an array of light sensitive photodiodes (or pixels) that convert incident light energy into electric charge. Solid state image sensors allow regions of a full frame of image data to be addressed.

In a full frame (or global) shutter operating mode, the entire imager is reset before integration to remove any residua! signal in the photodiodes. The photodiodes (pixels) then accumulate charge for some period of time (exposure period), with the light collection starting and ending at about the same time for all pixels. At the end of the integration period (time during which light is collected), all charges are simultaneously transferred to light shielded areas of the sensor. The Sight shield prevents further accumulation of charge during the readout process. The signals are then shifted out of the light shielded areas of the sensor and read out.

The output of the image sensor may be processed utilizing one or more functions or algorithms to condition the signal appropriately for use in further image processing downstream, including being digitized to provide a digitized image of target T.

Microcontroller 160 may perform a number of functions, such as controlling the amount of illumination provided by illumination source 146 by controlling the output power provided by iilumination source power supply 144. Microcontroller 160 may also control other functions and devices. Microcontroller 160 may include a predetermined amount of memory 162 for storing data.

The components in reader 1 12 may be connected by one or more bus 168 or data lines, such as an Inter-IC bus such as an I²C bus, which is a control bus that provides a communications link between integrated circuits in a system. This bus may connect to a host computer in relatively close proximity, on or off the same printed circuit board as used by the imaging device. I²C is a two-wire serial bus with a software-defined protocol and may be used to link such diverse components as the image sensor 154, temperature sensors, voltage level translators, EEPROMs₁ general-purpose I/O, A/D and D/A converters, CODECs, and microprocessors/microcontrollers.

The functional operation of the host processor 118 involves the performance of a number of related steps, the particulars of which may be determined by or based upon certain parameters stored in memory 166 which may be any one of a number of memory types such as RAMI, ROM, EEPROM, etc.. In addition some memory functions may be stored in memory 162 provided as part of the microcontroller 160. One of the functions of the host processor 118 may be to decode machine readable symbology provided within the target or captured image. One dimensional symbologies may include very large to ultra-small, Code 128, Interleaved 2 of 5, Codabar, Code 93, Code 11 , Code 39, UPC, EAN, and MSI. Stacked 1 D symbologies may include PDF, Code 16K and Code 49. 2D symbologies may include Aztec, Datamatrix, Maxicode, and QR-code.

Decoding is a term used to describe the interpretation of a machine readable code contained in an image projected on the image sensor 154. The code has data or information encoded therein. Information respecting various reference decode algorithm is available from various published standards, such as by the Internationa! Standards Organization ("ISO").

Operation of the imaging and decoding, which may be executed in a user or factory selectable relationship to a scanning routine, may be governed by parameters which are enabled for processing as a part of an autodiscrimination process, whether imaging or decoding is to be continuous or discontinuous, etc. Permitted combinations of imaging, scanning and decoding parameters together define the imaging-scanning-decoding relationships or modes which the reader will use. In the continuous mode (also referred to as continuous imaging or scanning mode, continuous streaming mode, streaming mode, fly-by scanning mode, on the fly scanning mode or presentation mode) the reader is held in a stationary manner and targets (such as symbols located on packages) are passed by the reader 112. In the continuous mode, the reader takes continuous image exposures seriatim and continuously decodes or attempts to decode some or ail of these images. In the continuous mode exposure times and decoding times may be limited.

Discontinuous mode is a mode wherein imaging, scanning and/or decoding stops or is interrupted and initiated with an actuation event, such as pulling of a trigger 115. to restart. An exemplary utilization of the reader in discontinuous mode is via hand held operation. While triggered, the image reader may expose images continuously and decode images continuously. Imaging, scanning or decoding stops once the image reader is no longer triggered. Exposing of images however, may continue. In the discontinuous mode, the exposure time, decoding time out limits and decoding aggressiveness may be increased more than those set for continuous mode. The discontinuous mode is typically initiated because the operator knows a symbol is present. The decoder therefore may forego making a determination of the presence of a symbol because a symbol is presumed to be in the field of view. Discontinuous mode may provide longer range scanning than the continuous mode.

Switching between continuous and discontinuous modes may be accomplished by use of a trigger 115 located on the reader. For example, when the trigger is depressed by an operator the reader may operate in a discontinuous mode and when the trigger is released the reader may switch to continuous mode after a predetermined period of time. A scanning subroutine may specify an address buffer space or spaces in which scan data is stored and whether scanning is to be continuous or discontinuous.

Another example of switching between continuous and discontinuous modes may be accomplished by symboiogy wherein switching between the modes depends on the type of symboiogy detected. The reader may stop attempting to decode a symbol after a predetermined time limit. The reader may limit the type of symbols to decode when in the continuous mode.

The aiming pattern generator may be programmed to operate in either continuous or discontinuous modes.

In the continuous mode, the present device may be configured to automatically switch to a reduced power state if no symbol has been sensed for a period of time. Upon sensing of a symbol the scanner may then automatically switch back to the higher power state continuous mode. In this reduced power state the scanner may change from having the aimer and/or illumination light sources on for every scan to having either/or on for only some of the scans (e.g. every 2 or 3 or less scans). In this manner the system may still be in a position to sense the presence of a symbol, but will draw less current and also generate less internal heating. After sensing a symbol, the image reader may utilize aiming/ϋlumination for every scan until another period of inactivity is sensed.

Mode changes may be accomplished by the host computer in response to an appropriate signal over either a direct connection or wireless connection to the scanner.

Another example of switching between modes may be accomplished by use of a trigger 115 located on the reader 112. For example, an operator may want to switch a reader's operation between two different modes, such as picture taking vs. data capture or reading only Aztec symbols vs. other symbologies or switching between continuous and discontinuous modes of operation. Switching between modes may be accomplished by detection of quick double-clicks of the trigger 115 and use detection of a quick double-click to toggle the reader in some way between different configurations and/or modes of operation. Additionally, which configuration/mode is active may be signaled back to the operator through a visual indicator (such as an LED) or an audible indicator, such as a beeper tone. The visual indication may be through different colors or patterns of blinking. The audible indicator may indicate through a beeping pattern or tone.

Different reader configurations or modes may be defined via menuing, with the trigger toggling action actually stepping through a sequence of compounded menu commands. Additionally, the time within which two clicks are considered a double-click may be predetermined and adjusted, such as by a menu. in exemplary configurations considered herein the aimer illumination sources are not operated during the exposure period of the image sensor and therefore the aimers do not necessarily contribute a specular reflection component derived from the region of interest (ROI). However the aimer in other configurations may also become a source of specular reflection.

FIG. 3 and FIG. 4 illustrate a document or form 218 with various types of data and images that may automatically be collected by an image reader 112. The collection process involves the human operator placing a target, such as a document or form in the field of view of an image reader. The operator may actuate a trigger on an image reader 112 for any data type to be read or the reader 112 may automatically image the target. The data shown may include typed text, an IBI, such as a two-dimensional barcode encoding a label number, a signature, hand-written text, etc. An image reader 112 may be placed on a stand 210 for viewing a document 218 which may be placed on a surface or platen 216.

An image reader 112 may be used as a document scanner or imager as well as an IBS reader for use in certain exemplary situations, such as a pharmacy application, wherein a pharmacy may desire to keep electronic records of documents or forms, such as prescriptions. The image reader may be placed in a stand 210, and prescription documents or other forms 218 may be placed under the image reader, and images of the prescription documents may be taken. Prescriptions may be on many different sizes of paper, which may result in different image file sizes, some of which may be undesirably large. For example, a large document may take up the entire field of view of the image reader, however a very small document may only take up a small portion of the imager field of view.

A method to minimize image file size may be to binarize the image (i.e. turn it into a 1 bit-per-pixel image so that each dot or pixel is either black or white instead of grayscale), and then compress the data using a lossless algorithm such as a CCiTT T6 Group 4 compression.

It may not be desirable to retain an entire image after a form is imaged, in an exemplary embodiment, the size of an image may be reduced through a process referred to herein as image cropping or automatic image cropping. An exemplary- image cropping process is taking an image, looking at that image to determine a region or regions of interest, and cropping the image so that the resulting image only includes the region(s) of interest. The unwanted portions of the image are cut or cropped out of the image. Other exemplary embodiments may include correction of angular distortion or incorrect rotational orientation caused by improper location of the imager relative to the object being imaged. In another exemplary embodiment, other image processing may be utilized on the image taken for different effects, such as flattening of the image (i.e. adjusting to make the dark/light contrast uniform across the cropped image), or other fiitering techniques which may help to make the resulting image more appealing

An exemplary embodiment for cropping an image may be to search at least two digitized images, one image taken at full or high resolution, and one taken with reduced or lower resolution for nominally straight edges within the image(s). These nominally straight edges may then be characterized in terms of length and direction (i.e. vectors). By a histogram of the directions, a determination may be made as to which edge orientation predominates. All edges not nominally parallel or perpendicular to the predominate orientation may be discarded. A group of edges that comprise a form may then be chosen by their proximity to the center of the image and then their proximity to other remaining edge positions. The process may then transmute a rectangle bounding those edges into a rectified image.

The digitized images may be binarized if they are captured as grayscale images. Binarization is turning the pixels of an image from grayscale or pixels having multibit values to binary value pixels, so that each dot or pixel is either black (e.g. 1 ) or white (e.g. 0). The higher and lower resolution images may be derived or obtained from a single image capture taken by the image reader, viewed both at high resolution and at reduced or lower resolution. FuS! resolution may be considered the highest resolution. The searches for nominally straight edges may be done in succession. Both sets of straight edges may contribute to the same pool of candidate edges. Some edges may appear in both images, and contribute twice to the search.

An exemplary embodiment for cropping an image may be to search a digitized image for nominally straight edges within the image. These nominally straight edges may then be characterized in terms of length and direction. By a histogram of those directions, a predominate (or predominant) orientation may be determined. Al! edges not nominally parallel or perpendicular to the predominate orientation may be discarded. A group or plurality of edges that comprise a form may then be chosen by their proximity to the center of the image and then their proximity to other remaining edge positions. The process may then transmute a rectangle bounding those edges into a rectified image.

An exemplary histogram analysis may consist of a series of one-dimensional slices along horizontal and vertical directions defined relative to the orientation of edges. In an embodiment, the value for each one-dimensiona! slice corresponds to the number of zero valued pixels along a pixel slice. An exemplary histogram analysis may provide a two-dimensional plot of the density of data element pixels in the image data. Edges may be determined with respect to a minimum density threshold for a certain number of sequential slices. In an embodiment, a histogram analysis searches inwardly along both horizontal and vertical directions until the pixel density rises above a predefined cut-off threshold.

An exemplary embodiment for determining the region or regions of interest determination of image processing may be implemented depending on the complexity desired by a user. For example, the region or regions of interest may be determined by having a known template on the surface 216 where the document or form 218 to be imaged is placed. The exemplary template may have a known pattern such as evenly spaced dots, or a grid of some type, wherein so that placing a document on the grid breaks the pattern and reveals where the document is. The form 218 may be used as an alignment guide to adjust the image reader stand tray 216 so that documents or forms to be imaged or scanned are placed in the center of the image reader's optics or field of view.

Another exemplary embodiment for finding the region, or regions, of interest is by mapping the energy of the image. High energy areas (i.e. areas with large pixel value variation in relatively close proximity, thus representing high contrast areas) might be considered regions of interest. After these high energy areas are established, an area within the image may be determined by including all of these regions of interest, and the image is cropped to that new area.

Another exemplary technique may include determining congruent Sines of activity for rotational adjustment.

Another exemplary embodiment is to provide location of the stand 210 or stand tray 216 relative to the area to be imaged, wherein angular distortion may be determined and correction applied.

Edge data may be utilized to establish predominant orthogonal horizontal and/or vertical directions which may be interpreted as representing features of a form if the presence of a form has not been assumed. If the predominant horizontal and/or vertical edges have been established, horizontal and/or vertical outer form boundaries may be established. In an exemplary embodiment, predominant horizontal edges may be established first, and then predominant vertical edges.

Figures 4a-4c illustrate three views of an exemplary image reader system. A reader 112 is held on a stand 210. A base or platen 216 provides a place for a document or form to be placed. The exploded view of Fig. 4c illustrates an exemplary hanging or positioning system for the reader to be hung or positioned on the stand for easy removal in order that an operator may image or scan documents or items which may not be located on the base or platen.

Figures 5a-5e illustrate five views of an exemplary image reader system. The housing 116 of the reader 112 may have an inclined indentation 230, which receives a hook 238, 242 in order that the reader may be "hung" on a stand for imaging forms placed on the base 216. The reader 112 may be removable from the stand 210 and then returned to the stand substantially in it's original position so that the forms placed on the platen 216 will be imaged correctly. The stand assembly may be adjusted for optimum reading of a document after return of the reader 112 to it's original adjusted position after removal. The bottom housing of the reader may have a molded pocket 230 and the stand may have molded retaining features.

The pocket 230 may be molded at an angle and with a width and depth that makes it easily removable from the stand while securing the reader accurately when placed in the stand. In this example a pocket mates with a molded feature in a stand retainer.

In an exemplary embodiment, there may be a vertical rib pocket 230 in the reader bottom housing that mates with a vertical rib 242 in the stand retainer 234. These features stabilize the reader and accurately return the reader substantially to it's original adjusted position. Both the exemplary pocket and retaining features may be molded into existing reader and stand parts and may not require additional parts, tooling, or costs.

Figure 6 illustrates an exploded view of an exemplary image reader housing. The housing 116 may comprise two shell halves (116', 116"), which are placed together and held together by a snap ring 250 which may be external to the two halves. The endcap may be molded two internal snap arms. The top and bottom housings will have corresponding recesses to accept the snap arms 252, 254. In an exemplary embodiment, the two housings may be positioned together and two screws assembled to one or more front bosses, in an exemplary assembly procedure, this action will initially attach the two housings to each other. The endcap may then be pushed over a protrusion ( system tail ) formed by the two housings. The endcap may be tapered 256 to draw the two housings to each other. The snap arms of the endcap may ultimately rest in recessed areas of the two housings, in their original stress free molded position. The housing recesses may prevent the endcap from disengaging.

An exemplary endcap may also provide a stop and strain relief for the cable end. There may be two small openings 260 in the right and left sides of the housings at their intersection. These openings may provide a means of unlatching the endcap for disassembly and repair. To unlatch the endcap, a small wire to both side openings and push the snap arms inward and free of the housing recesses and then push the endcap rearward to release it. A lanyard may also be molded into the endcap.

Figures 7a-7e illustrates four views of an exemplary image reader system stand base or platen 216, which may hold a document in position for imaging. Documents may not always align with the reader optical system field of view. An exemplary system and method may align the tray/document to the optical field of view and retain that position once aligned. The system may be realigned at a later date. An exemplary mechanism may provide adjustability and retention.

An exemplary base assembly 216 may comprise a sheet assembly (slide 216' and base 216"), held together with one ore more rivets or protrusions 276 which are free to slide relative one another to provide front to back adjustment. The slide path is determined by the slot 278 the rivets pass through. A tray 216"' may have protrusions 280 that mate with slots 282 in the base part which may provide side to side adjustment for the system and carry the tray during the front to back adjustment of the slide. The clamp may follow a slot in the slide. Base assembly 216 may also comprise a clamp 270 and a damp screw 274 wherein the clamp is held in position by the clamp screw. The mechanism and the tray are sandwiched between the damp and the clamp screw. When alignment of the tray is complete, the screw is tightened and the clap and screw prevent movement of the base assembly and tray. If realignment is required, the screw may be loosened and an alignment procedure repeated. The screw slot may be shaped so a tool such as a coin may be used to tighten or loosen the screw.

The reader may capture images of many sized documents. To insure that the user can readily place the document to be imaged completely in the FOV (field of view), a document placement guide may be required.

In an exemplary embodiment, the location of an aimer crosshair pattern in the FOV would be measured at the time of manufacture and stored in the imager engine. A calibration document 218 may have a crosshair pattern 290 printed at a location such that when the page is placed on the base assembly the printed crosshair and the laser crosshair coincide with each other to achieve proper alignment.

In an exemplary embodiment for performing calibration, a user may read a menu IB! to enable the aimer, align the crosshairs of the aimer and calibration page and then fasten the document guide to the stand's base plate at the corner of the calibration page. The specific calibration page may also include an IBI that contains the imager engine serial number such that during caiibration the image engine could read the IBI and verify that that the correct calibration page is being used. This serial number may also be in human readable form for visual verification. Software which creates this calibration page may be shipped with the system so a user may print a new calibration page. In an exemplary embodiment, a calibration form may be utilized that has a defined calibration symbol printed thereon, such as at its center. To perform calibration a user would read an IBI to put the reader in calibration mode and then place the calibration page in its view. The system may emit audio feedback, such as in the form of a series of clicks (or beeps) at an interval that would correspond to the distance of the calibration symbol to the center of the FOV. The closer the calibration symbol becomes to the center the faster the clicks would occur until when the center is reached the clicks would stop (null spot). If the calibration symbol moved away from the center the dicks would start again. Once the center was located the user may then fasten the document guide to the stand's base plate at the corner of the calibration page.

In an exemplary embodiment, the location of an aimer crosshair pattern in the FOV may be measured at the time of manufacture and stored in the image engine. The stand may be shipped with a calibration form that has a calibration grid printed thereon, such as at its center. To perform calibration a user would read a menu IBI to put the in calibration mode which would enable an aimer pattern, such as crosshairs. The user would then place the calibration page such that the aimer crosshair coincided with one of the line intersections formed by the printed grid. The system would emit audio feedback in the form of a series of clicks (or beeps) at an interval that would correspond to the distance of the aimer crosshair to the desired grid intersection, as determined from the previously stored location of the aimer pattern. The closer the crosshair is to the correct grid intersection the faster the clicks occur. When the correct grid intersection was under the aimer crosshair the clicks would stop (null spot). If the aimer crosshair moved away from the desired grid intersection the clicks would start again. Once the proper intersection was located the user may then fasten the document guide to the stand's base plate at the corner of the calibration page.

In an exemplary embodiment, the image reader stand may have an adjustment to adjust the height of the image reader. It should be understood that the programs, processes, methods and apparatus described herein are not related or limited to any particular type of computer or network apparatus (hardware or software). Various types of genera! purpose or specialized computer apparatus may be used with or perform operations in accordance with the teachings described herein. While various elements of the preferred embodiments have been described as being implemented in software, in other embodiments hardware or firmware implementations may alternatively be used, and vice-versa. The iliustrated embodiments are exemplary only, and should not be taken as limiting in scope. For example, the steps of the flow diagrams may be taken in sequences other than those described, and more, fewer or other elements may be used in the block diagrams. Also, unless applicants have expressly disavowed any subject matter within this application, no particular embodiment or subject matter is considered to be disavowed herein.

Claims

1. An imaging system for imaging a target comprising:

an image reader having a field of view for imaging a target, the image reader having a housing with an inclined indentation;

a stand adapted for holding the image reader a distance from the target, the stand having an inclined hook;

a positioning apparatus for positioning the target within the field of view;

wherein the inclined hook mates with the inclined indentation to hold the image reader and the image reader is removable from the stand in order that the image reader may image targets not placed in the positioning apparatus.

2. An imaging system in accordance with claim 1 , wherein the image inclined indentation comprises a vertical rib pocket and the inclined hook comprises a vertical rib.

3. An imaging system in accordance with claim 1 , wherein the positioning apparatus comprises a platen.

4. An imaging system in accordance with claim 1 , wherein the positioning apparatus comprises a platen attached to the stand.

5. An imaging system in accordance with claim 1 , wherein the positioning apparatus is a platen having an alignment apparatus for aligning targets within the field of view when the image reader is held on the stand.

6. An imaging system in accordance with claim 1 , wherein the image reader comprises an aimer for generating an aimer pattern on the target.

7. An imaging system in accordance with claim 1 , wherein the image reader comprises an aimer for generating an aimer pattern on the target and the aimer pattern is comprised of cross hairs.

8. An imaging system in accordance with claim 1 , wherein the target comprises a form having a calibration pattern provided thereon and the image reader comprises an aimer for generating an aimer pattern on the target and an operator uses the aimer pattern to align the aimer pattern with the calibration pattern