Abstract:
A scanner with variable scan range. The scanner comprises a plurality of scan units and at least one joint mechanism corresponding to the scan units. The scan units are mechanically and electrically connected, and the scan range is variable for scanning objects of different sizes.

Description:
BACKGROUND  
       [0001]     The invention relates to a scanner with a variable scan range, and in particular to a scanner having a plurality of joined scan units which can overlap or stretch to vary the scan range.  
         [0002]     Typically, conventional scanners have a fixed scan range, for example a scanner for A5 size documents cannot be applied to A4 size documents, or a scanner for A4 size documents cannot be applied to A3 size documents. When documents of various sizes are to be scanned, various scanners with different scan ranges or one scanner with a large scan range, which often occupies excessive space, must be employed.  
       SUMMARY  
       [0003]     An embodiment of a scanner are provided. The scanner comprises a plurality of scan units and at least one corresponding joint mechanism. The scan units are mechanically and electrically connected, and the scan range is variable for scanning objects of different sizes.  
         [0004]     The joint mechanism comprises a pivot member on each scan unit, whereby the scan units are made rotatable to overlap or stretch. The pivot member can be a hinge.  
         [0005]     The joint mechanism comprises at least one guide member on one scan unit and at least one curved groove on another scan unit. The guide member is slidably disposed in the curved groove to enable the scan units to rotate and overlap or stretch. The guide member can be a cylinder or a semi-cylindrical shaft.  
         [0006]     Each scan unit has a feed slot for the scanned object. In some embodiments, the joint mechanism comprises two guide members and two semicircular grooves disposed on two sides of the feed slot respectively. The two semicircular grooves correspond and form a substantially circular groove. When the scanner is folded by overlapping the scan units, both sides of the scanned object can be scanned. When the scanner is stretched by unfolding the overlapping scan units, a single side of the scanned object can be scanned.  
         [0007]     A first scan unit has at least one protrusion, while a second scan unit has at least one hole. The scan units are positioned by means of the protrusion engaging the hole when the scan units overlap or stretch.  
         [0008]     The joint mechanism comprises at least one protrusion on one scan unit and at least one opening on another scan unit. The protrusion engages the opening to join the scan units, thereby adjusting the scan range of the scanner. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:  
         [0010]      FIG. 1  is a perspective view of an embodiment of a scanner of this invention;  
         [0011]      FIGS. 2   a ,  2   b  and  2   c  show the scanner of  FIG. 1  switching among different scan ranges;  
         [0012]      FIG. 3   a  is a perspective view of another embodiment of a scanner;  
         [0013]      FIG. 3   b  is schematic view shows the scanner of  FIG. 3   a  scanning documents;  
         [0014]      FIG. 4   a  is a perspective view shows the scanner of  FIG. 3   a  in a stretched configuration;  
         [0015]      FIG. 4   b  depicts the scanner of  FIG. 4   a  scanning a document;  
         [0016]      FIGS. 5   a  and  5   b  depict an embodiment of a joint mechanism of the scanner of  FIG. 3   a;    
         [0017]      FIG. 6  depicts the joint mechanism of  FIGS. 5   a  and  5   b  joining the scan units;  
         [0018]      FIGS. 7   a  and  7   b  depict a signal wire of a scanner of  FIG. 3   a  between the overlapped scan units;  
         [0019]      FIG. 7   c  depicts a signal wire of a scanner of  FIG. 4   a  between the stretched scan units;  
         [0020]      FIGS. 8   a  and  8   b  depict another embodiment of a joint mechanism of  FIG. 3   a;    
         [0021]      FIG. 9   a  is a schematic view of a scan unit with rollers according to the invention;  
         [0022]      FIG. 9   b  is a schematic view shows the scan units of  FIG. 9   a  scanning a document;  
         [0023]      FIG. 10  is a schematic view of another embodiment of a scanner;  
         [0024]      FIG. 11  depicts a joint mechanism of the scanner of  FIG. 10 ;  
         [0025]      FIG. 12  depicts the scanner of  FIG. 10  scanning a document;  
         [0026]      FIG. 13  is a schematic view of another embodiment of a scanner of  FIG. 10 ;  
         [0027]      FIG. 14  depicts the scanner of  FIG. 13  scanning a document;  
         [0028]      FIGS. 15   a  and  15   b  are schematic views shows scan units with joint mechanism of another embodiment of a scanner;  
         [0029]      FIG. 16   a  depicts the scan units overlapped of a scanner of  FIG. 15   a;    
         [0030]      FIG. 16   b  is an exploded view of the scanner of  FIG. 16   a;    
         [0031]      FIG. 17   a  depicts the scanner of  FIG. 16   a  in a stretched configuration; and  
         [0032]      FIG. 17   b  is an exploded view of the scanner of  FIG. 17   a.   
     
    
     DETAILED DESCRIPTION  
       [0033]     Referring to  FIG. 1 , a scanner  1000  comprises scan units  10 ,  20 ,  30  and a pivot member  100 . The scan units  10 ,  20  and  30  are joined by the pivot member  100 . The joined scan units  10 ,  20  and  30  rotate to overlap or stretch to vary the scan range. In this embodiment, the pivot member  100  is a hinge. Feed slots  12 ,  22  and  32  are defined on the scan unit  10 ,  20  and  30  respectively for feeding the documents to be scanned. Data reading devices  14 ,  24  and  34  are disposed on the inner wall of the feed slots  12 ,  22  and  32  for scanning the passing documents.  
         [0034]     In  FIG. 2   a , a 4 inch photo is passing the feed slots  12 ,  22  and  32 . As the scan units  10 ,  20  and  30  overlap, one, two or all three of the scan units  10 ,  20  and  30  can be selected to function when the document passes therethrough. In  FIG. 2   b , scan unit  30  is rotated to align with the scan unit  20 , thus, the scan range is enlarged, and a larger document  7  of A4 size, for example, can be accepted. At this time, either the scan units  20  or  30  is selected to function. In  FIG. 2   c , all the scan units  10 ,  20  and  30  are stretched to the maximum scan range, and capable of accepting an even larger document such as A3 size. Although three scan units are described in this embodiment, it is not limited thereto. Two scan units, four scan units or more scan units can be employed.  
         [0035]      FIG. 3   a  depicts another embodiment of the scanner of the invention. A scanner  1000  comprises a scan unit  50  and  60 . The scan units  50  and  60  can overlap as shown in  FIG. 3   b , or the scan unit  50  can rotate clockwise to stretch, thereby enlarging the scan range as shown in  FIG. 4   b . The joint mechanism between the scan units  50  and  60  is described in the following.  
         [0036]      FIGS. 5   a  and  5   b  depicts the joint mechanism between the scan units  50  and  60 . Two guide members  62  are disposed on the scan unit  60  and adjacent to a feed slot  66  as shown in  FIG. 5   a . In this embodiment, the guide member  62  is a cylinder. Two semicircular grooves  52  are formed on the scan unit  50  and adjacent to a feed slot  56  as shown in  FIG. 5   b . The guide members  62  slide in the grooves  52  enabling the scan units  50  and  60  to rotate, whereby the scan units  50  and  60  stretch to accommodate large size documents.  
         [0037]     As the scan units  50  and  60  are rotated to overlap or stretch as shown in  FIGS. 3   a  and  4   a  respectively, a data reading device  54  of the scan unit  50  and a data reading device  64  of the scan unit  60  must be disposed on the upper inner wall of the feed slots  56  and the lower inner wall of the feed slot  66  so as to scan the double sides of a scanned document as shown in  FIG. 7   a . In such a structure, when the scan unit  50  is rotated to stretch, the data reading devices  54  and  64  are positioned on the same side of the scanned document, whereby a large size document can be scanned.  
         [0038]     A signal wire  65  is provided to connect the data reading devices  54  and  64  electrically. When the scan units  50  and  60  overlap, as the data reading devices  54  and  64  are on opposite sides of the scanned document, the signal wire  65  connecting the data reading devices  54  and  64  extends cross the feed slots  56  and  66  as shown in  FIG. 7   b . As the signal wire  65  are disposed near the ends of the scan units  50  and  60 , the scanned document can pass without interference from the signal wire  65 . In  FIG. 7   b , the scan unit  50  is omitted to clearly show the signal wire  65 . When the scan unit  50  is rotated 180° and stretched, the signal wire  65  is also rotated. Thus, when the scan units  50  and  60  are stretched, signal wire  65  is disposed on the same side and does not extend across the feed slots  56  and  66 .  
         [0039]     In this embodiment, another type of the joint mechanism can be employed. As shown in  FIGS. 8   a  and  8   b , the joint mechanism comprises two semi-cylindrical shafts  67  and a depression  57  in which the shafts  67  are rotatably inserted, whereby the scan units  50  and  60  overlap or stretch. Additionally, the scan unit  60  further comprises a plurality of protrusions  63 , and the scan unit  50  further comprises a plurality of holes  53  corresponding to the protrusion  63 . The protrusions  63  engage the holes  53  to position the scan units  50  and  60  when the scan units  50  and  60  overlap or stretch.  
         [0040]     In the described embodiments, the scan units rotate to overlap or stretch. In the following embodiment, however, another type of joint mechanism is described.  
         [0041]      FIG. 9   a  depicts a scan unit with rollers. A scan unit  80  comprises at least one roller  81  on the bottom and a data reading device  83  also on the bottom. When a document is scanned, the scan unit  80  is rolled on the document, and the data reading device  83  reads the data on the document simultaneously as shown in  FIG. 9   b . In such circumstance, the joint mechanism between two scan units  80  comprises a plug (protrusion)  84  on one scan unit  80  and an opening  82  on another scan unit  80  as shown in  FIG. 11 . Two scan units  80  are joined by inserting the plug  84  into the opening  82  as shown in  FIGS. 10 and 12 . In addition to mechanical connection, electrical connection can also be accomplished by this joint mechanism.  
         [0042]     In this embodiment, more than two scan units  80  are applicable. For example, three scan units  80  can also be joined in this way as depicted in  FIGS. 13 and 14 .  
         [0043]      FIGS. 15   a  and  15   b  depict another embodiment of the plug-in type scanner. A scan unit  40  comprises a first pin  42  and a second pin  44 , and a scan unit  90  comprises a first pin hole  92  and a second pin hole  94 . When scan units  40  and  90  overlap, as shown in  FIG. 16   a , the first pin  42  and the second pin  44  are inserted into the first pin hole  92  and the second pin hole  94  respectively as shown in  FIG. 16   b . The scan unit  90  is separated from the scan unit  40  and rotated 180° to enable insertion of the first pin  42  and the second pin  44  into the second pin hole  94  and the first pin hole  92 , thereby the scan units  40  and  90  stretching to enlarge the scan range as depicted in  FIGS. 17   a  and  17   b . In addition to mechanical connection, the scan units  40  can also be electrically connected to the scan unit  90  by protrusion of the first pin  42  and the second pin  44  into the first pin hole  92  and the second pin hole  94 .  
         [0044]     While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.