Abstract:
A system for imaging a document including an imaging apparatus, which includes a camera positioned inside the imaging apparatus, the camera configured to acquire a plurality of images of a document in front of the camera. The document is place behind a glass window on a wall opposing the camera. The imaging apparatus includes an illumination system which is positioned around the glass window but outside the field of view (FOV) of the camera. The imaging apparatus further includes an opaque cover, which covers the whole glass window area. The cover includes a slit to insert a document to be imaged, a slit to remove the document and a groove that enables a user to move the document with his finger.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under 35 USC 119(e) from U.S. provisional application 60/881,512 filed Jan. 22, 2007, the disclosure of which is included herein by reference. 
     This application is a continuationinpart of application Ser. No. 10/959,261, filed Oct. 6, 2004 now U.S. Pat. No. 7,911,655, which is incorporated by reference in its entirety herein. 
     This application is also a continuationinpart of application Ser. No. 11/552,321, filed Oct. 24, 2006, which is incorporated by reference in its entirety herein. 
     This application is also a continuationinpart of application Ser. No. 11/552,989, filed Oct. 26, 2006 now U.S. Pat. No. 7,821,679, which is incorporated by reference in its entirety herein. 
     The disclosures of the above continuationinpart applications are incorporated herein by reference. 
     This application is related to the following U.S. patent applications:
     “System and method for scanning a business card from within ms outlook directly into the ms outlook contact file”, application Ser. No. 11/307,943 filed Feb. 28, 2006; and   “System and method for creating a visitor badge for a conference or exhibition from a scanned ID or smart card document,” application No. 60/763,455 filed Jan. 31, 2006.   

     The disclosures of the above relate applications are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to illumination systems and methods for cameras, and more particularly to illumination systems and methods for scanning devices for scanning a business card, an ID card, a passport and the like documents, providing an illumination which is substantially uniform. 
     BACKGROUND OF THE INVENTION 
     There exist in today&#39;s market scanning devices capable of reading ID cards, drivers license, business cards and the like. Scanning devices which include imaging sensors based on technologies such as a CCD or CMOS, require illumination of the scanned document. 
     Illumination coming from external sources such as room illumination often creates uncontrolled reflections on the scanned document, thereby distorting the image of the scanned document. Internal light sources may also bring about problems of reflections that distort the uniformity of the illumination of the scanned document, thereby causing the image of the scanned document not to be a substantially true image of the scanned document. 
     Reference is made to  FIGS. 1   a  (Prior art) and  1   b  (Prior art).  FIG. 1   b  depicts a hot spot  40  caused by direct illumination of the scanned document  10  or by illumination from external source entering the scanned from bare areas of the scanner glass window, and  FIG. 1   a  illustrates how hot spots  40  are formed by direct illumination of the scanned document  10  or glass window  20  in front of the scanned document. When imaging a document  10  with a camera  50 , document  10  needs to be illuminated. In conventional illumination method, as shown in  FIG. 1   a , illumination positions  31  and  32  enable the return of the majority of light to the lens of camera  50 , but give rise to a problem known in the art as hot spot  40 , where the light source ( 30 ) itself is imaged by camera  50 . 
     Thus there is a need for and it would be advantageous to have a camera based scanner that has an illumination system that provides uniform illumination with no reflections, hot spot effects, and other illumination artifacts. 
     SUMMARY OF THE INVENTION 
     In view of the limitations now presented in the prior art, the present invention provides a new and useful system that can enhance the quality of scanned documents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become fully understood from the detailed description given herein below and the accompanying drawings, which are generally not drawn to scale and are given by way of illustration only and thus, not limitative of the present invention, and wherein: 
         FIG. 1   a  (Prior art) illustrates the hot spot problem caused by direct illumination of the scanned document or external light sources. 
         FIG. 1   b  (Prior art) depicts a hot spot caused by direct illumination of the scanned document and clear window in front of the scanned document. 
         FIG. 2  depicts a perspective view of the scanner with uniform illumination, according with embodiments of the present invention, as seen from outside the scanner. 
         FIG. 3  depicts a perspective view of a cross section of the scanner with uniform illumination, according with embodiments of the present invention. 
         FIG. 4  illustrates a lighting configuration, according with the preferred embodiment of the present invention, providing uniform illumination. 
         FIG. 5  depicts an example lighting configuration of the scanner with uniform illumination, according with the preferred embodiment of the present invention, as viewed from the camera point of view. 
         FIG. 6  depicts a front view illustration of the preferred embodiment of the cover of a scanner with uniform illumination, according with embodiments of the present invention. 
         FIG. 7  depicts the preferred embodiment of the cover of a scanner with uniform illumination, according with embodiments of the present invention, as viewed through the window, from the camera point of view. 
         FIG. 8  is a front view illustration of an embodiment of a cover of a scanner with uniform illumination, according with embodiments of the present invention. 
         FIG. 9  is a front view illustration of an embodiment of a cover of a scanner with uniform illumination, according with embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is an improved scanner for scanning business cards, ID cards, passports and the like documents, having illumination which is substantially uniform. The scanner includes a camera and at least one light source such as a LED light source (herein after referred to as LED), the light source being disposed outside the camera field of view (FOV). The scanner also includes a fixed cover that prevents internal light from being transmitted outside the optical chamber of the scanner, and more importantly, prevents external light from entering the optical chamber of the scanner and possibly distorting the uniformity of the illumination. 
     Before explaining embodiments of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the host description or illustrated in the drawings. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art of the invention belongs. The methods and examples provided herein are illustrative only and not intended to be limiting. 
       FIG. 2  depicts a perspective view of a scanner  100  with uniform illumination, according with embodiments of the present invention, as seen from outside scanner  100 . Scanner  100  includes the body  110  enclosing the scanner optical chamber, camera chamber  150  containing camera unit  50  and a fixed cover  120 . 
       FIG. 3  depicts a perspective view of a cross section of scanner  100  with uniform illumination, according with embodiments of the present invention. The cross section cuts out the top wall of scanner  100 . Scanner  100  includes camera chamber  150  located at the back of scanner  100  and containing camera unit  50 . The camera lens ocular  52  is viewing the scanner optical chamber  160 , which is enclosed on its opposite side by a window  20 , which is a transparent window such as of glass, hard clear plastic or the like, hereinafter referred to as “window” or “glass window”. Document  10  is to place behind glass window  20 , and camera  50  is focused on the document plan. 
       FIG. 4  illustrates a lighting configuration, according with the preferred embodiment of the present invention, providing uniform illumination. In this embodiment, one or more light sources  202  are directed towards reflecting walls  155  and  165  which form optical chamber  160 , whereas all the rays that bounce off walls  155  and  165  create a uniform white illumination inside optical chamber  160 , which illuminates glass window  20  and thereby document  10  with no reflections, hot spot effects, and other illumination artifacts. One or more light sources  202  are positioned such that they are out of the field of view (FOV)  60  of camera  50 , the FOV outlined by lines  62  between which camera  50  can “see”. Limiting the FOV such that camera  50  cannot “see” light sources  202  prevents hot spots from being formed on glass window  20  and thereby on document  10 . 
       FIG. 5  depicts an example lighting configuration  201  of a scanner  100  with uniform illumination, according with the preferred embodiment of the present invention, and as viewed from the camera point of view. In this example, lighting configuration  201  includes four (4) rows of LED light sources  202  disposed around glass window  20 . Since camera  50  can view only glass window  20 , light sources  202  do not form hot spots on glass window  20  and thereby on the image of document  10 . 
     Light sources  202  may comprise IR illumination, UV illumination, visible light illumination and other bands of wave length as required, to process colored documents, documents with special backgrounds such as water marks and any other visible and invisible printed materials used. Scanner  100  is controlled by a processor which also controls light sources  202 . The processor may select the light source type and control the light source intensity, by using Pulse Width Modulation (PWM), for example. 
     For the sake of clarity, light sources  202  may be any type of light source, but scanner  100  of the present invention preferably uses LED light sources  202 , including IR, UV and visible light LED light sources. 
     Scanner  100  also includes a fixed cover  120  that prevents external light from entering optical chamber  160  and possibly distorting the uniformity of the generated illumination. Fixed cover  120  also prevents internal light from being transmitted outside optical chamber  160  of the scanner  100 . 
       FIG. 6  is a front view illustration of the preferred embodiment of fixed cover  120 , according with embodiments of the present invention, and  FIG. 7  depicts cover  120  of scanner  100  as viewed through window  20 , from the camera point of view, inside optical chamber  160 . Referring also to  FIG. 2 , fixed cover  120  covers glass window  20 . Cover  120  includes an opaque plate with a mechanism to allow the insertion of a document  10  to be scanned, and the removing of document  10  after being scanned. 
     In the preferred embodiment of the present invention, the mechanism that allows the insertion, moving and removing of document  10 , includes:
         a) a slit  124  to insert document  10 ;   b) a slit  126  to remove document  10 ; and   c) a groove  122 .   Groove  122  enables a user to move document  10  in the groove directions  123 , using, for example, the user&#39;s finger  99  or the eraser side of a pencil  99  or means the like that fit inside groove  122 . When document  10  is inserted and being scanned, document  10  itself blocks light from entering or leaving optical chamber  160  through groove  122 .       

       FIG. 8  is a front view illustration of another embodiment of a document moving mechanism for a cover  120  of scanner  100 , according with embodiments of the present invention. The mechanism which allows the insertion, moving and removing of document  10 , includes:
         a) a slit  124  to insert document  10 ;   b) a slit  126  to remove document  10 ; and   c) a groove  127 .   Document  10  is inserted into slit  124  and dropped down by the force of gravity. Groove  127  enables a user to move document  10  in the groove directions  129 , using, for example, the user&#39;s finger  99  or the eraser side of a pencil  99  or means the like that fit inside groove  127 . When document  10  is inserted and being scanned, document  10  itself blocks light from entering or leaving optical chamber  160  through groove  127 .       

       FIG. 9  is a front view illustration of another embodiment of a document moving mechanism for a cover  120  of scanner  100 , according with embodiments of the present invention. The mechanism which allows the insertion, moving and removing of document  10 , includes:
         a) a slit  124  to insert document  10 ;   b) a slit  126  to remove document  10 ; and   c) a groove  128 .   Groove  128  enables a user to move document  10  in the groove directions  121 , using a moving mechanism, for example, a pin  98 , which, for example can be in idle situation pushed back by a force such as a spring. When needing to move document  10 , the pin is pushed against document  10  move while the pushing pressure is kept on. Pin  98  may include a high friction, elastic element on pin  98  internal end, such as a rubber element to balance the pressure on document  10  and improve the control of moving document  10 . When document  10  is inserted and being scanned, document  10  itself blocks light from entering or leaving optical chamber  160  through groove  128 .       

     It should be note that grooves in all embodiments can be extended such the document  10  can be removed from both or either side of fixed cover  120 , and slit  126  is disposed on both or appropriate side of cover  120 , respectively with the groove horizontal positioning. 
     It should be note that grooves in all embodiments can be extended such the document  10  can be removed automatically by connecting the pin  98  to an electric motor/magnetic coils or pneumatic means. 
     Florescence image of the document may be acquired by illuminating the document with excitation light in UV, NUV or blue wavelength and acquiring data from the green and red sensitive pixels of a color sensitive sensor array. An optical filter designed to block the excitation wavelength may be used to protect the sensor. 
     Although the present invention has been described with reference to the preferred embodiment and examples thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have suggested in the foregoing description, and other will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the following claims.