Abstract:
Briefly, in accordance with one or more embodiments light may be channeled via a light-channeling apparatus during scanning.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]     This Application is a continuation application of U.S. application Ser. No. 10/065,384, filed Oct. 11, 2002. The entire disclosure of U.S. application Ser. No. 10/065,384 is considered as being part of the disclosure of the present application and is hereby incorporated by reference herein in its entirety. 
     
    
     BACKGROUND OF INVENTION  
       [0002]     1. Field of Invention  
         [0003]     The present invention relates to a light-channeling apparatus and method. More particularly, the present invention relates to a light-channeling tube capable of preventing light dispersion and shielding against outside sources of light interference.  
         [0004]     2. Description of Related Art  
         [0005]     Following the rapid progress in computer capability and the development of Internet and multimedia technologies, the transmission of documents and images has become an essential element in communication. Textual information or image patterns are captured by a peripheral device such as an optical scanner and then converted into digital data by an analogue/digital converter. The digital data is transferred to an image file that can be displayed, identified, edited, stored or output.  
         [0006]     In general for a scanning system, the light source and the first reflecting mirror of a scanning module are exposed outside a scanning module and hence this is one of the major factors that affect scan quality. In other words, most of the light from a light source projected onto a document must be redirected onto the scanning region after reflection and the document image must be shielded against interference from external light sources so that the image is able to project onto the first reflecting mirror. Both are critical factors that determine the ultimate quality of the image as captured by the scanner.  FIG. 1  is a schematic diagram showing the position of a light source  120  and a first reflection mirror  130  inside a conventional scanning module  100 . As shown in  FIG. 1 , the light source  120  is installed inside a light source carrier  118  on a body casing  110 . The first reflecting mirror  130 , a second reflecting mirror  132 , a third reflecting mirror  134 , a lens  140  and a light-sensing device  150  is are enclosed inside the body casing  110 . Viewed from the top, the light source  120  and the first reflecting mirror  130  underneath light passage slit  112  can be easily seen. The light source  120  is, for example, a daylight lamp having a long edge similar in length to a document  160 . The slit  112  has a sufficient width that permits light reflected from the document  160  to project onto the first reflecting mirror.  
         [0007]     The light source  120  must project a line of light onto the document  160  to form a scan line there. To prevent the dispersion of light, most scanning systems have a collimating lens  122  installed above the light source  120  so that light from the light source  120  is focused on the document  160  to form an intense scan line. Although the lens  122  focuses light from the light source  120 , there is no guarantee that light will not be dispersed to the surrounding regions.  
         [0008]     Similarly, there is no facilities facility around the slit  112  that prevents stray lights from external sources from projecting onto the first reflecting mirror  130  and interfering with the quality of the reflected light coming from the document  160 . Ultimately, quality of the image may be affected.  
       SUMMARY OF INVENTION  
       [0009]     Accordingly, one object of the present invention is to provide a light-channeling apparatus and method for guiding light from a light source to a document with very little dispersion and guiding the reflected light from the document through a passage slit onto a first reflecting mirror inside a body casing such that very little stray lights from external sources are is permitted entry into the body casing.  
         [0010]     To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides a light-channeling apparatus for a scanning module. The scanning module includes a light source and a body casing. The body casing has a passage slit for light. The light-channeling apparatus comprises of a first guiding tube and a second guiding tube. The first guiding tube is connected to the body casing and positioned between the light source and the document. The second light-guiding tube is also connected to the body casing but positioned between the document and the passage slit.  
         [0011]     This invention also provides a scanning module for scanning a document. The scanning module mainly includes a body casing, a light source, a plurality of reflecting mirrors, a lens, a light-sensing device and a light-channel apparatus. The light source is mounted on the body casing for illuminating a document. The reflecting mirrors, the lens and the light-sensing device are enclosed inside the body casing. The light-channeling apparatus is connected to the body casing and that the light-channeling apparatus comprises of a first light-guiding tube and a second light-guiding tube. The first light-guiding tube is positioned between the light source and a document while the second light-guiding tube is positioned between the document and a light passage slit.  
         [0012]     According to one preferred embodiment of this invention, the light-guiding tube can be a hollow tube whose interior walls have a reflective coating. In addition, a collimating Lens is also installed inside the first light-guiding tube.  
         [0013]     According to another preferred embodiment of this invention, a light-guiding body may be incorporated inside the light-guiding tube. Furthermore, the document end of the first light-guiding tube and the document end of the second light-guiding tube may be physically connected together. Moreover, the light-guiding tube and the scanning module may be fabricated together as an integrative unit.  
         [0014]     It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0015]     The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention, In the drawings,  
         [0016]      FIG. 1  is a schematic diagram showing the position of a light source and a first reflection mirror inside a conventional scanning module  100 ;  
         [0017]      FIG. 2  is a schematic diagram showing various components of a scanning module according to one preferred embodiment of this invention;  
         [0018]      FIG. 3  is a cross-sectional view of the interior of a light-channeling apparatus according to one preferred embodiment of this invention; and  
         [0019]      FIG. 4  is a perspective view of a light-channel apparatus according to one preferred embodiment of this invention. 
     
    
     DETAILED DESCRIPTION  
       [0020]     Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.  
         [0021]      FIG. 2  is a schematic diagram showing various components of a scanning module according to one preferred embodiment of this invention. As shown in  FIG. 2 , the scanning module  200  includes a body casing  10 , a light source  120 , three reflecting mirrors  130 ,  132 ,  134 , a lens  140 , a light-sensing device  150  and a light-channeling apparatus  210 . The body casing  110  has a light passage slit  112 . The light source  120  is mounted on a carrier base  118  on the body casing  110  for illuminating a document  160 . The reflecting mirrors  130 ,  132 ,  134 , the lens  140  and the light-sensing device  150  are all enclosed inside the body casing  110 . The light-channeling apparatus  210  is attached to the body casing  110 . The light-channeling apparatus  210  comprises of a pair of light-guiding tubes  212  and  218 . The light-guiding tube  218  is positioned between the light source  120  and the document  160  while the light-guiding tube  212  is positioned between the document  160  and the slit  112 .  
         [0022]     As shown in  FIG. 2 , the light source  120  projects a beam of light towards the document  120 . The beam of light reflects from the document  160  and enters the body casing  110  through the slit  112 . After entering the body casing  110 , the beam of reflected light projects in sequential order onto the first reflecting mirror  130 , the second reflecting mirror  132  and the third reflecting mirror  134  before arriving at the lens  140 . The lens focuses the beam onto the light-sensing device  150 .  
         [0023]     The light-guiding tubes  212 ,  218  have a hollow tube structure. When light from the light source  120  travels to the document  160 , the light-guiding tube  218  focuses the beam of light on the document  160  and hence increases the luminance of the light beam. The light-guiding tube  212  channels the beam of reflected light from the document to the slit  112  before impinging upon the first reflecting mirror  130  inside the body casing  110 . With this arrangement, very little light is dispersed and interference by strayed lights from external light sources is minimized.  
         [0024]      FIG. 3  is a cross-sectional view of the interior of a light-channeling apparatus according to one preferred embodiment of this invention. To optimize the effects provided by the light-guiding tubes  212  and  218 , a collimating lens  122  is installed inside the light-guiding tube  218  and the interior sidewalk of both light-guiding tubes  212  and  218  are coated with a reflective layer  216 . Obviously, to increase light-focusing power, a light-guiding body  214  may also be incorporated inside the light-guiding tubes  212  and  218 . In other words, the light-guiding tubes not only guide the light beam from the light source  120  to the first reflecting mirror  130 , but also increase overall luminance level.  
         [0025]      FIG. 4  is a perspective view of a light-channel apparatus according to one preferred embodiment of this invention. One end of the light-guiding tubes  212  and  218  may be connected together to form the light-channeling apparatus  210  as shown in  FIG. 4 . In other words, the document end of the light-guiding tube  218  and the document end of the light-guiding tube  212  are joined together to facilitate installation. However, the light-guiding tubes and the scanning module may be fabricated together as an integrative unit to reduce production cost.  
         [0026]     In summary, major advantages of the scanning module of this invention includes:  
         [0027]     1. The light-guiding, tube of the light-channel apparatus focuses light from the light source on the document with a greater intensity.  
         [0028]     2. The light-guiding tube of the light-channel apparatus also focuses the light reflected from the document through a slit into the body casing.  
         [0029]     3. The scanning module is able to screen out unwanted interference from external light sources without incurring too much cost.  
         [0030]     It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.