Abstract:
A flatbed scanner includes a housing, a glass plate fixed to the housing, a front rib formed at a bottom face of a front part of the housing and extending downward, a back rib formed at a bottom face of the back part of the housing and extending downward, and side ribs formed at two sides of the housing and extending toward the center of the housing. The inner distance from the back rib to the front rib is not smaller than the length of the glass plate. The side ribs are under the bottom faces of the front part and the back part so as to form a fastening gap. Because the distance between the side ribs is smaller than the width of the glass plate, when the glass plate is inserted into the fastening gap, the glass plate is held.

Description:
BACKGROUND 
   This application claims the benefit of the filing date of Taiwan Application Ser. No. 092217157, filed Sep. 24, 2003, the content of which is incorporated herein by reference. 
   The invention relates to a flatbed scanner, and more particularly to a flatbed scanner with a short border such that a to-be-scanned book can completely attached to and completed supported by the flatbed scanner. 
   A scanner, copier and the like use an optical module to acquire an image of a to-be-scanned document. Various document support structures for supporting the to-be-scanned document as disclosed in, for example, Taiwan Patent Publication Nos. 364710, 477510, 484776 and 481405 have been developed and used. For example, in the conventional document support structures of the flatbed scanners, when the user wants to acquire the image of a book, the central binding portion C of the book B of  FIG. 1  cannot smoothly contact the glass plate  12  of the flatbed scanner because the limitation of the housing  11 . Thus, when the optical module OS scans the book B, the scanned image may have shadows and deformations at the central binding portion C of the book B because the optical path OT cannot reach the central binding portion C of the book B. 
   Taiwan Patent Publication No. 364710 discloses an upper housing of a flatbed scanner, in which a fastener at a side and three resilient fasteners at three sides are used to fasten the glass plate. In this case, the reliability is insufficient, and an auxiliary tape or other fixing members have to be used in order to prevent the glass plate from falling down. In addition, when the image of the book is scanned according to this structure, the optical path cannot reach the central binding portion of the book when the optical module is scanning because a gap is left between the book&#39;s central binding portion and the glass plate of the flatbed scanner. Hence, the scan result includes shadows, deformations and the like at the book&#39;s central binding portion. 
   Taiwan Patent Publication No. 477510 discloses a fixing structure for fixing a glass plate of a scanner using a fastener at a side and a plurality of ribs and a cam-link mechanism. According to this structure, when the image of the book is scanned, the optical path of the optical module cannot reach the book&#39;s central binding portion because a gap is left between the book&#39;s central binding portion and the glass plate of the flatbed scanner owing to the existence of the ribs. Hence, the scanned result includes shadows, deformations, and the like at the book&#39;s central binding portion. In addition, this structure has to use more members, so the assembly is complicated and the manufacturing cost is high. 
   Taiwan Patent Publication No. 484776 discloses a supporting mechanism for a glass plate of a scanner, wherein an inverse-U shaped sliding slot is used to fix the glass plate. According to this structure, when the book&#39;s image is scanned, the optical path of the optical module cannot reach the book&#39;s central binding portion owing to the step between the sliding slot and the glass plate. Hence, the scan result includes shadows, deformations and the like at the book&#39;s central binding portion. 
   Taiwan Patent Publication No. 481405 discloses a simple device for fixing a glass plate without adhesive, in which a plurality of seats is formed at four corners of the supporting mechanism and a plurality of projecting plates are formed at four edges to fixing the glass plate. According to this structure, when the book&#39;s image is scanned, the optical path of the optical module cannot reach the book&#39;s central binding portion because a step exists between the projecting plates and the glass plate. Hence, the scanned result includes shadows, deformations, and the like at the book&#39;s central binding portion. As shown in  FIG. 5  of this Taiwan patent, if the glass plate interferes with the seat and is then pressed into the seat (the two sides of the glass plate of  FIG. 5C  have reach the seat) when the glass plate is placed down, it means that the seat also has the property of resilient fixing property (the resilience of the glass plate is extremely poor), and the problem of insufficient reliability in the 364710 patent still exists in the 481405 patent. If the glass plate can be directly put into the seat without interfering with the seat when the glass plate is placed down, it is doubtful as to the actual reliability of preventing the glass plate from falling down using the anti-slip sheet during the transportation procedure (because it claims that no tape or other fixing member has to be used). 
   SUMMARY 
   In view of the above-mentioned problems, an object of the invention is to provide a simple structure, which is for making the optical path of the optical module reach the book&#39;s binding portion and is capable of preventing shadows and deformations from being caused in the scanned image at the book&#39;s binding portion. Thus, a clear scanned image may be obtained according to the document support structure of the flatbed scanner. 
   To achieve the above-mentioned object, the invention provides a flatbed scanner with a short border. The scanner includes a housing, a glass plate, a front rib, a back rib, and side ribs. The housing has a bottom, two sides, a front part and a back part. The front rib is formed at a bottom face of the front part and extends downward. The back rib is formed at a bottom face of the back part and extends downward. An inner distance from the back rib to the front rib is not smaller than a length of the glass plate. The side ribs are formed between the two sides and extend inward. The side ribs are under the bottom faces of the front part and the back part so as to form a fastening gap. Because the distance between the side ribs is smaller than the width of the glass plate, when the glass plate is inserted into the fastening gap, the glass plate is held without other elements. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a document support structure for a conventional flatbed scanner, wherein when the scanner is scanning a book, shadows and deformations will be caused at the book&#39;s central binding portion because the book cannot smoothly contact the glass plate of the flatbed scanner. 
       FIG. 2(A)  shows the pictorial view of a document support structure for a flatbed scanner of the invention. 
       FIG. 2(B)  shows a top view of  FIG. 2(A) . 
       FIG. 3  shows a cross-sectional view taken along a line A-A of  FIG. 2(B) . 
       FIG. 4  shows an enlarged view at a corner of  FIG. 3 . 
       FIGS. 5(A)  and (B) show cross-sectional views taken along a line B-B of  FIG. 2(B) . 
       FIGS. 6(A) to 6(C)  show schematic illustration of the glass plate mounted to the housing, wherein the length of the glass plate substantially equals the distance from the front rib to the back rib. 
       FIGS. 7(A) to 7(D)  show schematic illustrations of the glass plate mounted to the housing in another way, wherein the length of the glass plate is smaller than the distance from the front rib to the back rib. 
       FIGS. 8(A) to 8(D)  show schematic illustration of the glass plate mounted to the housing in still another way, wherein the length of the glass plate is smaller than the distance from the front rib to the back rib and the back rib is movable. 
       FIGS. 9(A)  and (B) show other cross-sectional views taken along the line B-B of  FIG. 2(B) . 
       FIGS. 10(A) to 10(C)  show schematic illustrations of the glass plate mounted to the housing of  FIG. 9 , wherein the length of the glass plate substantially equals the distance from the front rib to the back rib. 
       FIGS. 11(A) to 11(C)  show other schematic illustrations of the glass plate mounted to the housing of  FIG. 9 , wherein the length of the glass plate substantially equals the distance from the front rib to the back rib. 
       FIG. 12  shows still another schematic illustration of the glass plate mounted to the housing of  FIG. 9 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The flatbed scanner of the invention with a short border will be described with reference to the accompanying drawings. 
     FIG. 2(A)  shows the pictorial view of a document support structure for a flatbed scanner of the invention.  FIG. 2(B)  shows a top view of  FIG. 2(A) . As shown in  FIGS. 2(A) and 2(B) , the flatbed scanner  20  includes a housing  21  and a scanning platform  22 . The scanning platform may be a glass plate or other transparent members. The optical module (not shown) of the scanner  20  is moved in a length direction OD of the housing  21 . When the book is scanned, the length direction of the to-be-scanned book is caused to be in correspondence with the length direction of the housing  21 , and the binding portion of the book is caused to stack on the long side of the housing  21 , wherein symbol OD denotes the moving direction of the optical module and symbol SA denotes the scanning area. In order to make the scanning area of the scanning platform close to the side of the housing, the invention proposes a combination structure between the scanning platform and the housing. The combination structure includes a side structure, a front structure and a back structure. The so-called side structure represents the combined structure between the scanning platform and the side of the housing. The so-called front (back) structure represents the combined structure between the scanning platform and the front (back) end of the housing. 
     FIG. 3  shows a cross-sectional view taken along a line A-A of  FIG. 2(B) .  FIG. 4  shows an enlarged view of the region A of  FIG. 3 . As shown in  FIG. 3 , the region A is the side structure. As shown in  FIG. 4 , the side structure A includes a housing side  211 , a side rib (first fixing part)  212 , and a side projecting portion (second fixing part)  213 . The side rib  212  extends in a direction parallel to the glass plate. The side rib  212  and the side projecting portion  213  define an L shape, and may be integrally formed using an insulation material by way of plastic molding. The glass plate  22  and the housing  21  may be attached to each other by an adhesive tape. 
   In this embodiment, the housing  21  is not limited to the above-mentioned structure. For example, if the front and back structures have structures to prevent the glass plate from being moved in the lateral side direction, the side projecting portion  213  may be omitted such that the side of the glass plate  22  smoothly contacts the housing side  211 . In addition, the number of the side rib(s)  212  of the housing  21  may be one or more than one. In addition, although the side rib  212  is formed toward the inner direction, it may be formed toward the outer direction. In addition, it is possible to chamfer the end portions of the side rib  212  and the side projecting portion  213 . 
   Next, the front and back fixing structures between the housing  21  and the glass plate  22  will be illustrated.  FIGS. 5(A)  and (B) show cross-sectional views taken along a line B-B of  FIG. 2(B) . As shown in  FIG. 5(A) , the front structure includes a front housing  215 , a front projecting portion  2151 , and a front rib  2152 . The glass plate  22  is pushed against the front rib  2152  for fastening according to the resilience of the front projecting portion  2151 . The number of the front rib(s)  2152  may be one or more than one. As shown in  FIG. 5(B) , the back structure includes a back housing  216 , a back projecting portion  2161  and a back rib  2162 . The glass plate  22  is pushed against the back rib  2162  for fastening according to the resilience of the back projecting portion  2161 . The number of the back rib(s)  2162  may be one or more than one. 
     FIGS. 6(A) to 6(C)  show schematic illustration of the glass plate mounted to the housing, wherein the length of the glass plate substantially equals the distance from the front rib to the back rib. As shown in  FIG. 6(A) , because a clearance D 1  exists between the side rib  212  and the back rib  2162 , the first end of the glass plate  22  is firstly inserted into the clearance D 1 . Thereafter, because the housing is made of the resilient material, as shown in  FIG. 6(B) , the second end of the glass plate  22  may be pressed downward such that the glass plate  22  smoothly contacts the side rib  212 . Finally, the glass plate  22  is moved toward the front end and then to front rib  2152 . If the length of the glass plate  22  is slightly smaller than the distance from the front rib  2152  to the back rib  2162 , the glass plate  22  may be completely fastened between the front rib  2152  and the back rib  2162 . Hence, this method can fasten the glass plate without falling down by the front projecting portion  2151 , the back projecting portion  2161  and the side rib  212 . Consequently, the document support structure of the invention does not need any extra adhesive processing. 
     FIGS. 7(A) to 7(D)  show schematic illustrations of the glass plate mounted to the housing in another way, wherein the length of the glass plate is smaller than the distance from the front rib to the back rib. As shown in  FIG. 7(A) , because a clearance D 1  exists between the side rib  212  and the back rib  2162 , the first end of the glass plate  22  is first inserted into the clearance D 1 . Thereafter, as shown in  FIG. 7(B) , the second end of the glass plate  22  may be pressed down such that the glass plate  22  smoothly contacts the side rib  212 . Next, the glass plate  22  is moved toward the front end and then to the front rib  2152 . Because the length of the glass plate  22  is shorter than the distance from the front rib  2152  to the back rib  2162 , the back housing  216  is free from being bent and deformed when the glass plate  22  is pressed downward. However, this method causes a gap between the glass plate  22  and the back rib  2162 . So, as shown in  FIG. 7(D) , the back rib  2162  may form an L shape, and an engagement piece C is inserted into the gap from the back rib  2162  such that the glass plate is free from being moved back and forth. This method can fasten the glass plate without falling down by the front projecting portion  2151 , the back projecting portion  2161 , the side rib  212 , and the engagement piece C. Consequently, the document support structure of the invention does not need any extra adhesive processing. 
     FIGS. 8(A) to 8(D)  show schematic illustration of the glass plate mounted to the housing in still another way, wherein the length of the glass plate is smaller than the distance from the front rib to the back rib and the back rib is movable. As shown in  FIG. 8(A) , because a clearance D 1  exists between the side rib  212  and the back rib  2162 , the first end of the glass plate  22  is first inserted into the clearance D 1 . Thereafter, as shown in  FIG. 8(B) , the second end of the glass plate  22  may be pressed down such that the glass plate  22  smoothly contacts the side rib  212 . Next, the glass plate  22  is moved toward the front end and then to the front rib  2152 . Because the length of the glass plate  22  is shorter than the distance between the front rib  2152  and the back rib  2162 , the back housing  216  is free from being bent and deformed when the glass plate  22  is pressed down. However, this method may cause a gap between the glass plate  22  and the back rib  2162 . Consequently, as shown in  FIG. 8(D) , the back rib  2162  is a movable or rotatable member such that the back rib  2162  may be moved or rotated after the glass plate  22  has been positioned, and the back rib  2162  may push against the glass plate  22  so as to prevent the glass plate from being moved back and forth. This method may prevent the glass plate  22  from falling down by the front projecting portion  2151 , the back projecting portion  2161  and the side rib  212 . 
     FIGS. 9(A)  and (B) show other cross-sectional views taken along the line B-B of  FIG. 2(B) . As shown in  FIG. 9(A) , the front structure includes a front housing  215  and a front L-shaped fixing portion  2154 . The glass plate  22  is supported by the front L-shaped fixing portion  2154 . The number of the front L-shaped fixing portion(s)  2154  may be one or more than one. As shown in  FIG. 9(B) , the back structure includes a back housing  216 , a back projecting portion  2161 , and a back rib  2162 . The glass plate  22  may push against the back rib  2162  for fastening by the resilience of the back projecting portion  2161 . The number of the back rib(s)  2162  may be one or more than one. 
     FIGS. 10(A) to 10(C)  show schematic illustrations of the glass plate mounted to the housing of  FIG. 9 , wherein the length of the glass plate substantially equals the distance from the front rib to the back rib. As shown in  FIG. 10(A) , because the front L-shaped fixing portion  2154  of the front housing  215  has the L shape, the glass plate  22  may be mounted from the top, and this embodiment first attaches a double-sided adhesive component  2155  (e.g., a double-faced tape) to the front L-shaped fixing portion  2154  in order to fix the mounted glass plate. Next, as shown in  FIG. 10(B) , because a clearance D 1  exists between the side rib  212  and the back rib  2162 , the first end of the glass plate  22  is first inserted into the clearance D 1 . Thereafter, the second end of the glass plate  22  is pressed down such that the glass plate  22  smoothly contacts and fixes the double-sided adhesive component  2155 . 
     FIGS. 11(A) to 11(C)  show other schematic illustrations of the glass plate mounted to the housing of  FIG. 9 , wherein the length of the glass plate substantially equals the distance from the front rib to the back rib. As shown in  FIG. 11(A) , because the front L-shaped fixing portion  2154  of the front housing  215  has the L shape, the glass plate  22  may be mounted from the top. That is, the first end of the glass plate  22  may be first inserted into the clearance D 1 , and the second end of the glass plate  22  is pressed down such that the glass plate  22  smoothly contacts the front L-shaped fixing portion  2154 . Then, as shown in  FIGS. 11(B) and 11(C) , a fastening member  2156  is inserted from the top and is fastened to the front L-shaped fixing portion  2154  so as to hold and fix the glass plate  22 . 
   Of course, as shown in  FIG. 12 , it is also possible to movably arrange a fastening member  2157  on the front housing  215 . After the glass plate  22  is placed on the front L-shaped fixing portion  2154 , the fastening member  2157  is moved to fix and hold the glass plate  22 . 
   While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative of and not restrictive on the broad invention, and that this invention not be limited to the specific construction and arrangement shown and described, since various other modifications may occur to those ordinarily skilled in the art. For instance, the side ribs, the front rib and the back rib may be in the shape of a complete and long rib, or composed of a plurality of short ribs. 
   According to the invention, because the glass plate is located above the housing, the book&#39;s binding portion may be completely attached to the glass plate when the book is scanned. Thus, the optical path of the optical module may reach the book&#39;s binding portion. Consequently, it is possible to prevent shadows and deformations from being caused in the scanned image corresponding to the book&#39;s binding portion. Thus, a clear scanned image may be obtained. In addition, because the structure of the invention is simple, the manufacturing cost may be advantageously reduced. 
   The document support structure of the flatbed scanner may be applied to information associated electrical apparatuses such as scanners or copiers.