Abstract:
A device including a housing, an imaging engine and a transparent exit window. The imaging engine is located within the housing. The exit window is in the housing allowing light to pass from an exterior of the device to the imaging engine within the housing. The exit window has a plurality of segments. Each of the segments has a corresponding optical property.

Description:
BACKGROUND  
       [0001]    Optical devices such as scanners and imagers are typically contained within a housing. Generally, the housing includes a transparent exit window that serves to fully enclose the housing while allowing the passage of light therethrough. Typically, the exit window provides no additional optical function, but can introduce negative optical effects. 
       SUMMARY OF THE INVENTION  
       [0002]    The present application relates to a device comprising a housing, an imaging engine, and a transparent exit window. The imaging engine is located within the housing. The exit window is located in the housing and allows light to pass from an exterior of the device to the imaging engine within the housing. The exit window has a plurality of segments. Each of the segments has a corresponding optical property. 
         [0003]    The present application further relates to an exit window comprising a plurality of segments. Each of the segments has a corresponding optical property. The exit window is sized to be positioned in a housing of a mobile electronic device, and is transparent to allow light to pass from an interior of the housing to an exterior of the housing 
         [0004]    The present application further relates to a device comprising a housing, an imaging means located within the housing for collecting images, and a window means for allowing light to pass from an exterior of the device to the imaging engine within the housing. The window means has a plurality of segments. Each of the segments has a corresponding optical property. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0005]      FIG. 1  shows a perspective view of a device including an integrated optical exit window according to an exemplary embodiment of the present invention. 
           [0006]      FIG. 2  shows a perspective view of the device of  FIG. 1  with a top of a housing thereof removed to show the integrated optical exit window according to the exemplary embodiment of the present invention. 
           [0007]      FIG. 3  shows a cross-sectional view of the device of  FIG. 2  with the integrated optical exit window according to the exemplary embodiment of the present invention. 
           [0008]      FIG. 4  shows a view of the optical benefits that may be introduced by the integrated optical exit window according to the exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION  
       [0009]    The exemplary embodiments of the present invention may be further understood with reference to the following description and the appended drawings, wherein like elements are referred to with the same reference numerals. The exemplary embodiments of the present invention describe a system for an integrated exit window in an optical device. The exemplary embodiments of the integrated optical exit window comprise one or more optical segment zones. The use of the integrated optical exit window along with its advantages will be discussed in detail below. 
         [0010]    A conventional parallel plate exit window typically only serves to close the housing over optical components and allow light to pass through. Particularly in mobile devices, wherein space is very limited, the exit window may be located in close proximity to optical components, leading to difficulties such as internal reflection, optical distortion, etc. In the exemplary embodiments described herein, an integrated optical exit window is provided that may eliminate optical defects and provide beneficial optical effects. 
         [0011]    The integrated optical exit window will be described with reference to an arrangement for an optical scanning device. However, those skilled in the art will understand that this device is exemplary only and that the exemplary integrated optical exit window may be applied to any optical device with a window, such as a laser scanner. That is, in this description, the term “optical device” refers to any device that collects light for the purpose of collecting data such as a laser scanner, a bar code reader, an image scanner, a camera, a charge coupled device, etc. Also, those skilled in the art will understand that the term “transparent” refers to the ability of a material to pass light through itself. It should be noted that the optical device may be mobile or stationary. 
         [0012]      FIG. 1  shows an exemplary optical device  10 , which in this embodiment is a bar code scanner including an exit window  12  mounted in a housing  14  that includes, for example, a pistol grip  16  and a scanning actuator  18 . As shown in  FIG. 2 , a scanning engine  20  (e.g., an optical scanner) is mounted within the housing  14  along with supporting electronics, a battery, connectors, etc. The scanning engine  20  may include at least an illumination system and an imaging system, as will be illustrated below. As used in this disclosure, an imaging system may include any of the various types of systems for collecting optical data that are known in the art. As would be understood by those skilled in the art, the position of the scanning engine  20  relative to the exit window  12  is determined based on the properties of the scanning engine  20 , the exit window  12  and the desired functionality of the device  10 . Specifically, the optical properties of the exit window  12  and the scanning engine  20  dictate an optimal distance and angle between the scanning engine  20  and an inner face of the exit window  12  and, consequently, determining the size of a space  22  within the housing forward of the scanning engine  20 . The optical properties of the exit window  12  will be discussed in detail below. 
         [0013]      FIG. 3  shows a cross-sectional view of the optical device  10  with the transparent exit window  12  according to an exemplary embodiment of the present invention. The exit window  12  may be a composite, transparent exit. The exit window  12  may comprise a single layer or may comprise multiple layers of the same or different materials. The scanning engine may include an illumination element  24  and an imaging element  26 . The function of the illumination element  24  may be to illuminate an image to be captured by the device  10  in order to aid in quick and efficient processing. The illumination element  24  may pass light from, for example, a laser, an LED, etc. The function of the imaging element  26  is to capture the image for processing. Those of skill in the art will understand that the positions of the illumination element  24  and the imaging element  26  relative to one another, to the main body of the scanning engine  20 , and to the rest of the housing are only exemplary and that other positions are possible in other embodiments. 
         [0014]    The exit window  12  may be subdivided into separate functional zones.  FIG. 3  illustrates two such zones  16  and  18 . Zone  16  is disposed within the exit window  12  so as to aid in the operation of the illumination element  24 , while zone  18  is disposed to aid in the operation of the imaging element  26 . Each zone has a predetermined optical property and a predetermined relationship to the other zone or zones. Optical functions may be, for example, imaging focus, aiming pattern generation, illumination focus, etc. Zones may be molded as one part or may be formed on an individual basis by compression molding techniques. 
         [0015]      FIG. 4  shows an alternate view of the exemplary device  10 , with the illumination element  24  and imaging element  26  exposed by view cutaway  40 .  FIG. 4  illustrates effects that one exemplary exit window  12 , with functional zones  16  and  18  disposed as described above with reference to  FIG. 3 , may have on the performance of the device  10 .  FIG. 4  illustrates the illuminated area  42  that may be produced by the illumination element  24  using a standard parallel exit window. In this exemplary embodiment, the functional zone  16  may change the aim of the illumination to an alternate illuminated area  44 . Additionally, the functional zone  16  may aid in the generation of an aiming pattern by the illumination element  24 , so that a user of the device  10  may more easily aim at a desired image. 
         [0016]    Further,  FIG. 4  illustrates the effect that the exit window  12  may have on the imaging element  26 . A standard viewing area of the imaging element  26  may be represented by viewing area  46 . The exemplary zone  18  may change the focus of viewing area  46 , resulting in a modified viewing area  48 . The combined effects of the two zones  16  and  18  of the exit window  12  may thus improve the performance (e.g., time to capture an image, quality of captured image, etc.) 
         [0017]    The exit window  12  may further be formed in order to minimize the internal reflection of the light emitted by the illumination element  24 ; such internal reflection may interfere with the ability of the imaging element  26  to capture images outside the housing  14 . For example, in one exemplary embodiment, rather than having a flat surface that may create a mirror-like reflective effect, the exit window  12  may have a surface figure and profile to re-direct the reflected light emitted from the illumination element  24  such that it does not reflect into the imaging element  26 . This may reduce or minimize the internal reflection, and thus improve the performance of the imaging element  26 . 
         [0018]    It will be apparent to those skilled in the art that various modifications may be made in the present invention, without departing from the spirit or the scope of the invention. Thus, it is intended that the present invention cover modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.