Abstract:
A scanner includes a housing, a transparent platform, a scanning module, a motor, a front compensation element and a rear compensation element. The housing includes a front section, a rear section, and a scanning section. The transparent platform is installed on the housing for a document to be placed on. The scanning module is installed inside the housing for scanning the document. The motor is used to drive the scanning module. The front and rear compensation elements are installed inside the housing to assist the motor with starting and stopping the scanning module.

Description:
BACKGROUND OF INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a scanner. More specifically, the present invention discloses a scanner having compensation elements for increasing operation speed of a scanning module of the scanner.  
           [0003]    2. Description of the Prior Art  
           [0004]    A scanner is a widespread peripheral device for scanning documents and producing corresponding image data. The scanner may have some additional functions, such as faxing image data to a fax machine over telephone lines, transmitting the image data in an e-mail format over a network, or connecting to a printer to print the image data.  
           [0005]    Please refer to FIG. 1. FIG. 1 is a diagram of a scanner  10  according to the prior art. The scanner  10  comprises a housing  12 , a transparent platform  18  installed on the housing  12  for a document  20  to be placed on, a sliding rod  22  installed inside the housing  12 , a scanning module  14  slidably installed inside the housing  12  for scanning the document  20  along the sliding rod  22  so as to generate corresponding image signals of the document  20 , and a step motor  16  installed inside the housing  12  and electrically connected to the scanning module  14  for driving the scanning module  14  to move back and forth in a stepping manner so as to perform a scanning process.  
           [0006]    Please refer to FIG. 2. FIG. 2 is a top view of the scanner  10  according to the prior art. As shown in FIG. 2, the housing  12  of the scanner  10  comprises a front section  24 , a rear section  26 , and a document scanning section  28  between the front section  24  and the rear section  26 . The front section  24  is a region where the scanning module  14  is accelerated from a motionless state to a constant scanning speed, the rear section  26  is a region where the scanning module  14  is decelerated from the constant scanning speed to the motionless state, and the document scanning section  28  is a region where the scanning module  14  scans the document  20 .  
           [0007]    When the step motor  16  initiates to drive the scanning module  14  in the front section  24  to move backwards from a front end  30  of the housing  12 , the step motor  16  provides a torsional force to accelerate the scanning module  14  from the motionless state to the constant scanning speed, and then utilizes the constant scanning speed to perform the scanning process in the document scanning section  28 . Nevertheless, the scanning module  14  has a large weight so that the step motor  16  usually needs a long period of time and a long distance in the front section  24  to accelerate the scanning module  14  to the constant scanning speed. When the scanning module  14  completes the scanning process and moves to the rear section  26 , the step motor  16  reduces the torsional force to decelerate the scanning module  14  from the constant scanning speed to stop. The step motor  16  also needs a long period of time and a long distance in the rear section  26  to decelerate the scanning module  14  to stop, due to the large weight of the scanning module  14 . Likewise, the aforementioned process will occur when the step motor  16  drives the scanning module  14  to move forwards from a rear end  32  of the housing  12  to the front end  30  of the housing  12 . As mentioned above, the step motor  16  needs a long period of acceleration time and deceleration time to respectively initiate and stop the scanning module  14 , meaning that the front section  24  and the rear section  26  will occupy a large space in the housing  12 .  
         SUMMARY OF INVENTION  
         [0008]    It is therefore a primary objective of the claimed invention to provide a scanner having a front compensation element and a rear compensation element for increasing operation speed of a scanning module of the scanner.  
           [0009]    The claimed invention, briefly summarized, discloses a scanner. The scanner comprises a housing, a transparent platform, a scanning module, a motor, a front compensation element, and a rear compensation element. The housing comprises a front section, a rear section, and a scanning section. The transparent platform is installed on the housing for a document to be placed on. The scanning module is installed inside the housing for scanning the document. The motor is used to drive the scanning module. The front and rear compensation elements are installed inside the housing to assist the motor with starting and stopping the scanning module.  
           [0010]    It is an advantage of the claimed invention that the scanner can scan quickly by reducing the acceleration time and the deceleration time of the scanning module when the step motor initiates or stops the scanning module, and can further reduce space of the front section and the rear section so as to increase a scanning range of the document scanning section.  
           [0011]    These and other objectives and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0012]    [0012]FIG. 1 is a diagram of a scanner according to the prior art.  
         [0013]    [0013]FIG. 2 is a top view of the scanner depicted in FIG. 1.  
         [0014]    [0014]FIG. 3 is a diagram of a scanner according to the first preferred embodiment of the present invention.  
         [0015]    [0015]FIG. 4 is a top view of the scanner depicted in FIG. 3.  
         [0016]    [0016]FIG. 5 is a top view a scanner according to the second preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0017]    Please refer to FIG. 3. FIG. 3 is a diagram of a scanner  50  according to the first preferred embodiment of the present invention. As shown in FIG. 3, the scanner  50  comprises a housing  52 , a transparent platform  58  installed on the housing  52  for a document  60  to be placed on, a sliding rod  62  installed inside the housing  52 , a scanning module  54  slidably installed inside the housing  52  for scanning the document  60  along the sliding rod  62  so as to generate corresponding image signals of the document  60 , a step motor  56  installed inside the housing  52  and electrically connected to the scanning module  54  for driving the scanning module  54  to move back and forth in a stepping manner so as to perform a scanning process, a front compensation element  74  installed at a front end of the sliding rod  62  of the housing  52 , and a rear compensation element  76  installed at a rear end of the sliding rod  62  of the housing  52 .  
         [0018]    Please refer to FIG. 4. FIG. 4 is a top view of the scanner  50  depicted in FIG. 3. As shown in FIG. 4, the housing  52  of the scanner  50  comprises a front section  64 , a rear section  66 , and a document scanning section  68  between the front section  64  and the rear section  66 . The front section  64  is a region where the scanning module  54  is accelerated from a motionless state to a constant scanning speed, the rear section  66  is a region where the scanning module  54  is decelerated from the constant scanning speed to the motionless state, and the document scanning section  68  is a region where the scanning module  54  scans the document  60 .  
         [0019]    The front compensation element  74  and the rear compensation element  76  are both springs for storing and releasing elasticity. When the scanning module  54  of the scanner  50  is motionless, the scanning module  54  is locked at a front end  70  of the housing  52  by the step motor  56  so as to depress the front compensation element  74  to store elasticity. When the step motor  56  initiates to drive the scanning module  54  to move backwards from the front end  70  of the housing  52 , elasticity stored in the front compensation element  74  will be released to push the scanning module  54  positioned at the front section  64  backwards so as to quickly help the step motor  56  accelerate the scanning module  54  to a scanning speed. Shortening the acceleration time of the scanning module  54  initiated by the step motor  56  will allow the scanning module  54  to perform the scanning process swiftly, and to shorten a distance of the front section  64  while the scanning module  54  accelerates. When the scanning module  54  completes the scanning process and moves to the rear section  66 , the rear compensation element  76  positioning at a rear end of the rear section  66  will provide a force to push the scanning module  54  so as to reduce the deceleration time of the scanning module  54  that is stopped by the step motor  56 , and to shorten a distance of the rear section  66 . While the step motor  56  drives the scanning module  54  to move toward a rear end  72  of the housing  52 , the scanning module  54  depresses the rear compensation element  76  to store elasticity. This elasticity will be used to help the step motor  56  to initiate the scanning module quickly in the following scanning pass.  
         [0020]    Likewise, when the step motor  56  initiates to drive the scanning module  54  to move forwards from the rear end  72  of the housing  52 , the rear compensation element  76  will push the scanning module  54  in the rear section  66  so as to rapidly accelerate the scanning module  54  to the scanning speed. Furthermore, when the scanning module  54  completes the scanning process and moves to the front section  64 , the front compensation element  74  will provide a force to push the scanning module  54  in the front section  64  so as to quickly decelerate the scanning module  54  to stop. The front compensation element  74  will be depressed to store elasticity again. Therefore, the present invention scanner  50  reduces the acceleration and deceleration time of the scanning module  54 , and uses shorter distances in the front section  64  and the rear section  66 .  
         [0021]    Please refer to FIG. 5. FIG. 5 is a top view a scanner  90  according to the second preferred embodiment of the present invention. The difference between the scanner  50  and the scanner  90  is that the front compensation element of the scanner  90  is a first magnetic element  78 , and the scanner  90  further comprises a second magnetic element  80  installed on the scanning module  54 . Polarity of the first magnetic element  78  faces the same polarity of the second magnetic element  80 . Therefore, when the step motor  56  drives the scanning module  54  positioned at the front section  64  to move backwards away from the front end  70  of the housing  52 , the first magnetic element  78  and the second magnetic element  80  repel each other so as to push the scanning module  54  to quickly accelerate to the scanning speed. Likewise, the rear compensation element of the scanner  90  is a third magnetic element  82 , and the scanner  90  further comprises a fourth magnetic element  84  installed on the scanning module  54 . Polarity of the third magnetic element  82  also faces the same polarity of the fourth magnetic element  84 . As shown in FIG. 5, while the scanning module  54  completes the scanning process and moves backwards into the rear section  66 , the third magnetic element  82  and the fourth magnetic element  84  also repel each other to prevent the scanning module  54  from moving backwards, and to quickly stop the scanning module  54 .  
         [0022]    Of course, the front compensation element (the first magnetic element  78  or the second magnetic element  80 ) and the rear compensation element (the third magnetic element  82  or the fourth magnetic element  84 ) of the present invention scanner  90  also can be used alone to urge the step motor  56  to initiate and stop the scanning module  54  in the front section  64  and the rear section  66  of the scanner  90 , respectively. In addition, the step motor  56  of the scanners  50  and  90  can be installed at the front end or the rear end of the housing  52 , on the scanning module  54 , or inside the housing  52 .  
         [0023]    Nevertheless, the aforementioned descriptions utilize the step motor functioning as a driving device to drive the scanning module. The step motor has the same effect as the use of a DC motor or a servomotor.  
         [0024]    In contrast to the prior art, the present invention scanners  50  and  90  have the front compensation element  74  (the first magnetic element  78  or the second magnetic element  80 ) for providing a force to push the scanning module  54  to quickly accelerate to the scanning speed while the step motor  56  initiates the scanning module  54 , and the rear compensation element  76  (the third magnetic element  82  or the fourth magnetic element  84 ) for providing a force to push the scanning module  54  to rapidly decelerate while the step motor  56  stops the scanning module  54 . The present invention allows fast scanning by reducing the acceleration time and the deceleration time of the scanning module  54  while the step motor  56  initiates or stops the scanning module  54 . Furthermore, the present invention reduces space of the front section  64  and the rear section  66  so as to increase a scanning range of the document scanning section  68 .  
         [0025]    Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.