Abstract:
A scan method includes providing a scanner, including an image sensor, a reference pattern and a transmission mechanism. The image sensor scans the reference pattern to generate reference data. The transmission mechanism transmits at least one recording media between the reference pattern and the image sensor. Finally, the image sensor generates scan data, and the scanner compares the scan data with the reference data to obtain a transmission condition thereof.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to a scan method, and in particular to a scan method reducing the number of required detectors. 
         [0003]    2. Description of the Related Art 
         [0004]      FIG. 1   a  shows a conventional scanner  1 , comprising a media detector A, a scan-in detector B, an image sensor  10 , a weight  20  and a transmission mechanism  30 . Transmission mechanism  30  comprises a pick arm  31 , a roller  32 , a roller  33  and a roller  34 . 
         [0005]    When scanner  1  scans, recording media passes between weight  20  and image sensor  10 , and image sensor  10  captures image data therefrom. 
         [0006]    With reference to  FIG. 1   b , media detector A detects whether recording media P is in a transmission position A 1 , and scanner  1  performs scan process by auto document feeder or flatbed according to the detection result. When recording media P actuates the media detector A, the pick arm  31  raises, allowing placement of recording media P into the scanner  1 . During scanning, if the media detector A confirms the presence of recording media P in the transmission position A 1 , the scanner  1  continues the scan process. 
         [0007]    With reference to  FIG. 1   c , scan-in detector B confirms a distance between recording media P and a scan position, the position of the recording media P (in or out of the scanner  1 ), and detects paper jam. 
         [0008]    In conventional scanning, first, media detector A detects the presence of recording media P in transmission position A 1 . If present, transmission mechanism  30  transmits recording media P toward the image sensor  10 . When recording media P actuates scan-in detector B, image sensor  10  scans the recording media P. Finally, when media detector A and the scan-in detector B detect no recording media P, the scanner  1  stops. 
         [0009]    In conventional scanning, more then two detectors are required, increasing costs. 
         [0010]    U.S. Pat. No. 5,844,698 discloses a scan method, however, only one sheet of recording media can be scanned in a single scan process rather then continuous scanning of a plurality of recording media, since paper jam is indistinguishable from lack of media altogether. 
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    A detailed description is given in the following embodiments with reference to the accompanying drawings. 
         [0012]    The invention provides a scan method in which a scanner is provided, comprising an image sensor, a reference pattern and a transmission mechanism. The image sensor scans the reference pattern to generate reference data. Next, the transmission mechanism transmits at least one recording media between the reference pattern and the image sensor. Finally, the image sensor generates scan data, and the scanner compares the scan data with the reference data to obtain a transmission condition thereof. 
         [0013]    The embodiment reduces the required number of detectors and, thus, cost. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
           [0015]      FIG. 1   a  shows a conventional scanner; 
           [0016]      FIG. 1   b  shows function of media detector; 
           [0017]      FIG. 1   c  shows function of scan-in detector; 
           [0018]      FIG. 2   a  shows a scanner of a first embodiment of the invention; 
           [0019]      FIG. 2   b  shows a modified embodiment; 
           [0020]      FIG. 3  shows a reference pattern; 
           [0021]      FIG. 4   a  is a flowchart of the first embodiment; 
           [0022]      FIG. 4   b  shows recording media in a transmission position; 
           [0023]      FIG. 4   c  shows recording media passing between an image sensor and a weight; 
           [0024]      FIG. 4   d  shows recording media leaving the image sensor; 
           [0025]      FIG. 5  shows a scanner of a second embodiment of the invention; and 
           [0026]      FIG. 6  is a flowchart of the second embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims. 
         [0028]      FIG. 2   a  shows a scanner  100  of a first embodiment, comprising a media detector A, an image sensor  10 , a memory (not shown), a weight  20  and a transmission mechanism  30 . The transmission mechanism  30  comprises a pick arm  31 , a roller  32 , a roller  33  and a roller  34 . The weight  20  comprises a reference pattern  21  corresponding to the image sensor  10 . 
         [0029]    With reference to  FIG. 2   b , in an embodiment, the reference pattern  21  is not disposed on the weight  20 . In  FIG. 2   b , the reference pattern  21  is disposed on the surface of the scanner  100  corresponding to the image sensor  10 . The reference pattern  21  is disposed in an area M above the image sensor  10 . 
         [0030]    With reference to  FIG. 3 , the reference pattern  21  comprises alternate black and white or other pattern. The image sensor  10  scans the reference pattern  21  to generate reference data. The scanner  100  stores the reference data into the memory. The reference data can be stored when the scanner  100  is manufactured or started. 
         [0031]    When the scanner  100  scans, recording media passes between the weight  20  and the image sensor  10 , and the image sensor  10  captures image data therefrom. 
         [0032]    In the embodiment, control the number of detectors required is reduced, and thus cost. In the first embodiment, scan-in detector is omitted. 
         [0033]      FIG. 4   a  is a flowchart of the first embodiment. First, a scan order is input to the scanner  100  in a preparation state accordingly (S 11 ). Then, with reference to  FIG. 4   b , the media detector A detects the presence of recording media P in a transmission position A 1  (S 12 ). When present, the transmission mechanism  30  transmits the recording media P toward the image sensor  10  (S 13 ). If there is no recording media P in the transmission position A 1 , the scanner  100  scans by flatbed (S 121 ). Next, when the scanner  100  is in the preparation state, the image sensor  10  scans according to the time for transmitting the recording media P to the image sensor  10  to generate scan data, and the scanner  100  compares the scan data with the reference data (S 14 ). With reference to  FIG. 4   c , if the scan data differs from the reference data, the recording media P is located between the image sensor  10  and the weight  20 , and the scanner  100  enters a scan state (S 15 ). If the scan data is continuously identical to the reference data, paper jam is indicated, and the scanner  100  outputs a first error signal (S 141 ). 
         [0034]    In a modified embodiment, in step S 14 , the image sensor  10  scans normally according to the steps of the transmission mechanism transmitting the recording media P to the image sensor to generate the scan data. 
         [0035]    In the scan state, the image sensor  10  scans the recording media P (S 15 ). Then, the scanner  100  compares the scan data with the reference data according to a first time period T 1  and a second time period T 2  (S 16 ). The first time period T 1  is the time required to scan one recording media P. The second time period T 2  is shorter than the first time period T 1 . A first comparison result is achieved by comparing the scan data with the reference data according to the first time period T 1 . A second comparison result is achieved by comparing the scan data with the reference data according to the second time period T 2 . If the first comparison result is distinct, paper jam is indicated (for example, the recording media P is stopped as shown in  FIG. 4   c ), and the scanner  100  generates a second error signal (S 161 ). As shown in  FIG. 4   d , if the first comparison result is identical, the recording media P leaves the image sensor  10  and the weight  20 , and the scanner  100  restarts the scan state to scan next recording media P (back to step S 15 ). If the first comparison result is identical and the second comparison result is distinct, the scanner  100  functions normally. 
         [0036]    If the first comparison result is identical and the second comparison result is identical, no recording media P passes between the image sensor  10  and the weight  20 , and the scanner  10  detects the presence of recording media P in the transmission position A 1  (S 17 ). If no recording media P is present in the transmission position A 1 , the transmission mechanism removes residual recording media P from the scanner  100  and stops (S 18 ). If recording media P is present in the transmission position A 1 , the scanner  100  outputs a third error signal (S 171 ). 
         [0037]    The embodiment reduces the number of detectors required and cost of the scanner  100 . 
         [0038]      FIG. 5  shows a scanner  200  of a second embodiment, wherein the media detector A is omitted. 
         [0039]      FIG. 6  is a flowchart of the second embodiment. First, a scan order is input to the scanner  200  (S 21 ). If the flatbed is selected, the scanner  200  scans the recording media P by flatbed (S 211 ). If the auto document feeder is utilized, the scanner  200  enters a transmission state moving the recording media P toward the image sensor  10  (S 22 ). 
         [0040]    After the transmission mechanism runs predetermined steps in the transmission state, the scanner compares the scan data with the reference data (S 23 ). If the scan data is identical to the reference data, paper jam is indicated, and the scanner  200  generates a first error signal (S 231 ). If the scan data is distinct from the reference data, the recording media P reaches the image sensor  10 , and the scanner  200  enters a scan state (S 24 ). 
         [0041]    In the scan state, the image sensor  10  scans the recording media (S 24 ). Then, the scanner  200  compares the scan data with the reference data according to a first time period T 1  and a second time period T 2  (S 25 ). The first time period T 1  is the time required to scan one recording media P. The second time period T 2  is shorter than the first time period T 1 . A first comparison result is achieved by comparing the scan data with the reference data according to the first time period T 1 . A second comparison result is achieved by comparing the scan data with the reference data according to the second time period T 2 . If the first comparison result is distinct, paper jam is indicated, and the scanner  200  generates a second error signal (S 251 ). If the first comparison result is identical, the recording media P leaves the image sensor  10  and the weight  20 , and the scanner  200  restarts the scan state to scan next recording media P (back to step S 24 ). If the first comparison result is identical and the second comparison result is distinct, the scanner  200  functions normally. 
         [0042]    If the first comparison result is identical and the second comparison result is identical, there is no recording media passing between the image sensor  10  and the weight  20 , and the scanner  200  is operated to confirm the scan condition (S 26 ). If the absence of recording media P is confirmed, paper jam is indicated, and the scanner  200  outputs a third error signal (S 261 ). If scan process completion is accomplished, the transmission mechanism removes residual recording media P from the scanner  200  and stops (S 27 ). 
         [0043]    The second embodiment further reduces the number of detectors required in the scanner, decreasing cost thereof. 
         [0044]    The first time period T 1  and the second time T 2  period are dynamically modified according to real-time capacity of the memory of the scanner. 
         [0045]    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.