Patent Publication Number: US-2007097250-A1

Title: Imaging system and method

Description:
BACKGROUND OF THE INVENTION  
      Imaging systems used to generate a scanned image of an object generally comprise a lens element or a lens array and optionally one or more reflective mirrors for directing and focusing an optical signal reflected by or transmitted through an object onto a photosensitive element. However, setting up the optical elements of the imaging system is generally time-consuming and costly (e.g., time and costs associated with mounting and aligning the various optical components). 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following descriptions taken in connection with the accompanying drawings in which:  
       FIG. 1  is a diagram illustrating an imaging system in which an embodiment of an optical module in accordance with the present invention is incorporated;  
       FIG. 2  is a diagram illustrating another embodiment of an optical module in accordance with the present invention; and  
       FIG. 3  is a diagram illustrating a further embodiment of an optical module in accordance with the present invention; and  
       FIG. 4  is a diagram illustrating another embodiment of an optical module in accordance with the present invention.  
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS  
      The preferred embodiments of the present invention and the advantages thereof are best understood by referring to  FIGS. 1-4  of the drawings, like numerals being used for like and corresponding parts of the various drawings.  
       FIG. 1  is a diagram illustrating an imaging system  10  in which an embodiment of an optical module  12  in accordance with the teachings of the present invention is employed to advantage. Imaging system  10  may comprise any type of device for generating a scanned image of a object(s)  16  such as, but not limited to, a scanner, copier, multi-function device or facsimile machine. In the embodiment illustrated in  FIG. 1 , imaging system  10  comprises a platen  18  for supporting object(s)  16  thereagainst and a scanner carriage or optical head  22  for generating a scanned image of object(s)  16 . In some embodiments of the present invention, optical head  22  is configured to be movable relative to platen  18  and/or object(s)  16  for generating a scanned image of object(s)  16 . However, in other embodiments of the present invention, optical head  22  is configured to remain stationary while object(s)  16  move past optical head  22  for generating a scanned image thereof. Imaging system  10  may be configured for reflective scanning and/or transparency scanning. Further, it should be understood that optical head  22  may comprise additional elements and/or devices besides optical module  12  (e.g., a light source).  
      In the embodiment illustrated in  FIG. 1 , optical module  12  comprises a lens array  30  and a photosensitive element  32 . In operation, lens array  30  receives an optical signal  36  reflected by or transmitted through object(s)  16  and directs and/or otherwise focuses optical signal  36  onto photosensitive element  32  to facilitate conversion of optical signal(s)  36  into an electrical signal for generating an scanned image of object(s)  16 . In the embodiment illustrated in  FIG. 1 , optical module  12  is formed by integrally molding lens array  30  to photosensitive element  32 , thereby producing lens array  30  and photosensitive element  32  as a unitary molded unit. For example, in the embodiment illustrated in  FIG. 1 , optical module  12  comprises molded portions  40  and  42 . In operation, optical module  12  is formed by disposing lens array  30  and the photosensitive element  32  into an injection mold or other type of mold device in a desired position and/or alignment relative to each other. An optical medium is injected and/or otherwise placed within the mold about lens array  30  and photosensitive element  32  (and/or in desired locations relative to lens array  30  and/or photosensitive element  32 ) to form molded portions  40  and  42 . The optical medium used to form the molded portions  40  and  42  of optical module  12  may comprise a plastic, glass and/or other type(s) of material having desired optical properties. In the embodiment illustrated in  FIG. 1 , optical module  12  comprises photosensitive element  32  and lens array  30  integrally molded together as a unit. However, it should be understood that additional optical elements may be incorporated into the molded unit of optical module  12 .  
      In the embodiment illustrated in  FIG. 1 , molded portion  40  is disposed at a receiving end  46  of lens assembly  30  relative to optical signal  36  (e.g., at an end of lens array  30  where optical signal(s)  36  are received from object(s)  16 ), and molded portion  42  is disposed at an exit end  48  of lens array  30  (e.g., a location where optical signal  36  exits lens array  30 ) between exit end  48  and photosensitive element  32 . In the embodiment illustrated in  FIG. 1 , two molded portions are illustrated (e.g., molded portions  40  and  42 ). However, it should be understood that a greater or fewer quantity of molded portions may be used to form optical module  12 . For example, in the embodiment illustrated in  FIG. 1 , lens array  30  is disposed perpendicular (perpendicular or substantially perpendicular) to a direction from which optical signal(s)  36  is received from object(s)  16  such that molded portion  40  reflects optical signal(s)  36  towards receiving end  46  of lens array  30 . Thus, it should be understood that in other embodiments of the present invention (e.g., where optical module  12  is disposed parallel or substantially parallel to a direction in which optical signal(s)  36  is received from object(s)  16 ), molded portion  40  may be omitted.  
      In the embodiment illustrated in  FIG. 1 , molded portion  40  is formed having an internally reflective surface  52  for reflecting optical signal  36  received from object(s)  16  to and/or toward receiving end  46  of lens array  30 . For example, in operation, the mold used to form molded portion  40  of optical module  12  is formed having a desired angular configuration to produce a corresponding angular configuration of molded portion  40 , indicated generally by  54 , to facilitate reflecting of optical signal(s)  36  in a desired direction towards lens array  30 . In other embodiments of the present invention, a reflective element  56  is placed on an external surface of molded portion  40  to facilitate reflection of optical signal(s)  36  toward lens array  30 .  
      In the embodiment illustrated in  FIG. 1 , molded portion  42  is disposed between exit end  48  of lens array  30  and photosensitive element  32  to facilitate focusing of optical signal(s)  36  exiting lens array  30  onto photosensitive element  32 . In the embodiment illustrated in  FIG. 1 , an optical signal receiving surface of photosensitive element  32  is disposed perpendicular (perpendicular or substantially perpendicular) relative to a direction, indicated generally by  60 , for receiving optical signal(s)  36  from lens array  30 . However, it should be understood that photosensitive element  32  may be otherwise positioned relative to lens array  30 .  
       FIG. 2  is a diagram illustrating another embodiment of optical module  12  in accordance with the present invention. In the embodiment illustrated in  FIG. 2 , molded portion  42  is sized having a decreased length in the direction indicated generally by  60  compared to a length of molded portion  42  illustrated in  FIG. 1 , thereby decreasing the overall size of optical module  12 . To facilitate a shorter length of optical module  12  having the same (e.g., the same or substantially the same) optical signal  36  travel distance of the embodiment illustrated in  FIG. 1 , molded portion  42  comprises reflective surfaces  62  and  64  for reflecting therein and/or otherwise directing optical signal  36  exiting from exit end  48  of lens array  30  to photosensitive element  32 . For example, in operation, as optical signal  36  exits exit end  48  of lens array  30 , optical signal  36  is reflected by surface  62  toward surface  64 . The optical signal  36  is then reflected by surface  64  to photosensitive element  32 . In the embodiment illustrated in  FIG. 2 , the mold for forming molded portion  42  is configured to produce surface  62  at a desired angle relative to a path of optical signal  36  exiting lens array  30  to facilitate reflection of optical signal  36  from surface  62  to surface  64 . For example, in the embodiment illustrated in  FIG. 2 , molded portion  42  is formed such that surface  62  is disposed at a predetermined angle relative to a path of optical signal  36  (e.g., non-perpendicular to a path of optical signal  36 ), indicated generally by  68 , to provide a desired reflective path for optical signal  36 . In some embodiments of the present invention, the optical medium used to form molded portion  42  creates surfaces  62  and  64  being internally reflective such that additional reflective materials on surfaces  62  and  64  are unnecessary. However, in other embodiments of the present invention, reflective materials may be applied and/or otherwise provided on surfaces  62  and  64  to facilitate reflection of optical signal(s)  36  within molded portion  42 .  
       FIG. 3  is a diagram illustrating a further embodiment of optical module  12  in accordance with the present invention. In the embodiment illustrated in  FIG. 3 , molded portion  42  is formed to reflect optical signal(s)  36  therein, thereby decreasing an overall length of optical module  12  while having the same (e.g., the same or substantially the same) optical signal  36  travel distance of the embodiment illustrated in  FIG. 1 . For example, in the embodiment illustrated in  FIG. 3 , molded portion  42  is formed having a rearward surface  70  (e.g., a surface of molded portion  42  disposed opposite end  48  of lens array  30 ) at a desired and/or predetermined angle relative to a path of optical signal  36  exiting end  48  of lens array  30  to facilitate reflection of optical signal(s)  36  from surface  70  to a surface  72  of molded portion  42 . In the embodiment illustrated in  FIG. 3 , molded portion  42  is preferably formed by having a portion of a mold disposed within an area indicated generally by  76  to form surface  72  at a desired and/or predetermined angle to facilitate reflection of optical signal(s)  36  from surface  72  to photosensitive element  32 . Preferably, surfaces  70  and  72  are internally reflective such that additional reflective materials are unnecessary. However, it should be understood that reflective materials may be externally applied to surfaces  70  and  72  of molded portion  42  to facilitate reflection of optical signal(s)  36  within molded portion  42 .  
       FIG. 4  is a diagram illustrating another embodiment of optical module  12  in accordance with the present invention. In the embodiment illustrated in  FIG. 4 , photosensitive element  32  is formed and/or otherwise molded at least partially within a portion of molded portion  42 . In the embodiment illustrated in  FIG. 4 , molded portion  42  is formed to facilitate reflection of optical signal(s)  36  therein to direct optical signal(s)  36  to photosensitive element  32  from lens array  30 . In the embodiment illustrated in  FIG. 4 , photosensitive element  32  is disposed adjacent exit end  48  of lens array  30  below a path of optical signal(s)  36  exiting lens array  30 , and an optical signal receiving surface of photosensitive element  32  is disposed in a position parallel (parallel or substantially parallel) to a plane of platen  18  and/or object  16 .  
      In the embodiment illustrated in  FIG. 4 , molded portion  42  is formed having a reflective surface  80  disposed at a desired and/or predetermined angle relative to a path of optical signal(s)  36  exiting end  48  of lens array  30 , indicated generally by  82 , to facilitate reflection of optical signal(s)  36  from surface  80  to photosensitive element  32  via a surface  84  of molded portion  42 . Preferably, molded portion  42  is formed such that surfaces  80  and  84  comprise internally reflective surfaces to facilitate reflection of optical signal(s)  36  within molded portion  42 . However, it should be understood that reflective materials may be externally applied to areas of molded portion  42  corresponding to surfaces  80  and  84  to facilitate reflection of optical signal(s)  36 . Further, it should be understood that photosensitive element  32  and/or molded portion  42  may be otherwise located and/or configured. For example, in some embodiments of the present invention, molded portion  42  may be flipped and/or inverted such that photosensitive element  32  is located near an upper surface of optical module  12  (e.g., toward platen  18 ). It should also be understood that photosensitive element  32  may molded entirely within molded portion  42 , partially within molded portion  42  or molded to an outer surface of molded portion  42 .  
      Thus, embodiments of the present invention enable easier and more precise formation of an optical module by molding at least a lens array and a photosensitive element as a single unit in a desired position and/or alignment relative to each other. Further, embodiments of the present invention enable improved reliability as optical modules formed in accordance with the teachings of the present invention are less susceptible to misalignment caused by vibration or other movement. Additionally, optical modules formed in accordance with the teachings of the present invention are less susceptible to dust and/or other foreign matter which may otherwise impede the quality of a scanned image of an object.