Abstract:
A calibration mechanism is positioned in a scanning device. The scanning device includes a scanning module having a transparent plate for being passed through a scanned light beam and creating a scanned color. The calibration mechanism includes a processor means and a display means. The display means is positioned to face the transparent plate of the scanning module and controlled by the processor means to alter the scanned color to a display color. Since, the calibration mechanism is capable altering the background color. Furthermore, the calibration mechanism has a simple structure and a compact size for conveniently positioned in a compact scanning device.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a calibration mechanism, more specifically, to a calibration mechanism capable of alternating the background color and a scanner having the calibration mechanism. 
         [0003]    2. The Related Art 
         [0004]    Generally, a scanning module is fixed in a scanning device with an auto document feeder. A document is conveyed by rollers positioned in the auto document feeder to pass the scanning module for being scanned. Conventionally, the color of a calibration sheet positioned in the scanning device is constant. 
         [0005]    If the scanned document is a light color paper such as a white paper, then the calibration sheet must be manually replaced as a dark color sheet such as a black color sheet. If the scanned document is a dark color paper such as a black color paper, then the calibration sheet must be manually replaced as a light color sheet such as a white color sheet. Since, the contrast is strong enough between the color of the scanned document and the color of the calibration sheet for improving de-skew function and edge detection function of the scanning device. 
         [0006]    If the scanned document is thin and the calibration sheet is white, then the dark images printed on opposite sides of the document will be influenced each other to reduce quality of the scanned image. Therefore, the calibration sheet must be replaced as a dark sheet to prevent the influence in this case. The calibration sheet must be altered to be white or black to adjust the shade of the scanning module of the scanning device for improving the quality of the scanned image. 
         [0007]    However, it is inconvenient to manually replace the white calibration sheet and the black calibration sheet, and store the calibration sheets. Since, the calibration mechanism capable of alternating the background color is popular nowadays. 
         [0008]    U.S. Pat. No. 7,518,766 discloses a calibration mechanism of a scanner. The calibration mechanism of the scanner includes a second light source, a calibration element having an opening, a first light source and a scanning module. The second light source is assembled with the calibration element, and the first light source is disposed at a position opposite to the calibration element. During the shading correction, the calibration element is rotated by an angle so that the first light source illuminates on a surface of the calibration element, and the reflected light enters the scanning module. When a transmissive original is being scanned, the light of the second light source passes through the opening of the calibration element and the transmissive original, and then enters the scanning module. 
         [0009]    U.S. Pat. No. 7,411,704 discloses a multiple-background device for a scanner and a calibration device utilizing the same principle. The multiple-background device includes a shaft, a low-reflectance portion and a high-reflectance portion are formed along the length of the shaft. Thereby the shaft can provide various background colors, and the optical module can acquire a plurality of scan lines by means of rotating the shaft for image calibration. 
         [0010]    U.S. Pat. No. 7,391,540 discloses a sheet-fed scanner capable of switching backgrounds. In the sheet-fed scanner, a scanning module scans a document, which is transported by a sheet-feeding mechanism across a scan region, and a stationary background component, which has a plurality of sections having different reflectivities and is disposed in the scan region. The scanning module includes an image sensor, a lens and at least one reflecting mirror. An actuator actuates the at least one reflecting mirror to enable the image sensor to selectively sense one of the sections of the background component as a scan background for the document through the lens and the at least one reflecting mirror. 
         [0011]    However, the above calibration mechanism has a complex structure and a large volume. Since, a space in the scanner must be reserved for the above calibration mechanism to increase the volume of the scanner. It is difficult to achieve a compact size of the scanner. 
       SUMMARY OF THE INVENTION 
       [0012]    An object of the present invention is to provide a calibration mechanism capable of alternating the background color. 
         [0013]    According to the invention, the calibration mechanism is positioned in a scanning device. The scanning device includes a scanning module having a transparent plate for being passed through a scanned light beam and creating a scanned color. The calibration mechanism includes a processor means and a display means. The display means is positioned to face the transparent plate of the scanning module and controlled by the processor means to alter the scanned color to a display color. 
         [0014]    An object of the present invention is to provide a scanning device capable of alternating the background color. 
         [0015]    According to the invention, the scanning mechanism includes an auto document feeder, the scanning module, the processor means and the display means. The auto document feeder conveys a document along a document conveying path. The scanning module senses a scanning light beam passing through a transparent plate positioned beside the document conveying path and creating a scanned color. The display means is positioned to face the transparent plate of the scanning module and beside the document conveying path. The display means is controlled by the processor means to alter the scanned color to a display color. 
         [0016]    Since, the calibration mechanism positioned in the scanning device is capable altering the background color. Furthermore, the calibration mechanism has a simple structure and a compact size for conveniently positioned in a compact scanning device. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The present invention will be apparent to those skilled in the art by reading the following description of preferred embodiments thereof, with reference to the attached drawings, in which: 
           [0018]      FIG. 1  shows a calibration mechanism positioned in a scanning device with an auto document feeder according to the present invention; 
           [0019]      FIG. 2  is a block diagram showing a first preferred embodiment of the calibration mechanism according to the present invention; 
           [0020]      FIG. 3  shows a first preferred embodiment of a display means of the calibration mechanism according to the present invention; 
           [0021]      FIG. 4  shows the display means of the calibration mechanism positioned to face a scanning module of the scanning device according to the present invention; 
           [0022]      FIG. 5  shows a second preferred embodiment of the display means of the calibration mechanism according to the present invention; and 
           [0023]      FIG. 6  is a block diagram showing a second preferred embodiment of the calibration mechanism according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0024]    Please refer to  FIG. 1  and  FIG. 2 . A calibration mechanism  1  is positioned in a scanning device  200  and includes a detection means  10 , a processor means  12  and a display means  14 . The scanning device  200  includes a base  202  and an auto document feeder  204  positioned on the base  202 . 
         [0025]    The auto document feeder  204  includes a document conveying path  206 , an input tray  208 , a picking up module  210 , a separating module  212 , a plurality of conveying rollers  214 , a scanning module  216 , a discharging module  218  and an output tray  220 . The document conveying path  206  defines an upstream section  222  and a downstream section  224  respectively connected to the outside of the auto document feeder  204 . 
         [0026]    The input tray  208  is connected to the auto document feeder  203  and positioned to adjacent to the upstream section  222  for being put a bundle of documents. The picking up module  210  is positioned at the upstream section  222  for picking up a document from the input tray  208  and conveying the document into the document conveying path  206 . 
         [0027]    The separating means  212  includes a driving roller  226  and a driven roller  228 , which is positioned at the upstream section  222  and at a downstream position relative to the picking up means  210 . The separating means  212  separates overlapping documents into a single document P and conveying the single document P to the downstream section  224 . Especially, the driven roller can be replaced by a separating pad. 
         [0028]    The conveying rollers  214  are dispersed along the document conveying path  206  for conveying the document P from the upstream section  222  to the downstream section  224 . The discharging means  218  is positioned at the downstream section  224  for discharging the document P from the document conveying path  206 . Since, the document P is put on the output tray  220 . 
         [0029]    The scanning module  216  includes an optical sensor  230 , a light source  232 , a transparent plate  234  and a reflective plate  236 , which is positioned beside the document path  2206  and in the base  204 . The light source  232  radiates a light beam to the document conveyed by the conveying rollers  214 . The light beam is reflected by the document, and then passing the transparent plate  234 , and then reflected by the reflective plate  236 , and then received by the optical sensor  230 . The optical sensor  230  transforms the light beam into an image. The transparent plate  234  is positioned beside the document conveying path  206  for protecting the scanning module  216  and preventing the scanning module  216  from dust. 
         [0030]    The detection means  10  of the calibration mechanism  1  is positioned beside the document conveying path  206  and at a downstream position relative to the separating means  212  and at an upstream position relative to the scanning module  216 . The display means  14  of the mechanism  1  is positioned beside the conveying path  206  and to face the transparent plate  234  of the scanning module  216 . Especially, the detection means  10  is positioned to close to the separating means  212 . The processor means  12  interconnects the detection means  10  and the display means  14 . 
         [0031]    Please refer to  FIG. 3  and  FIG. 4 . A first preferred embodiment of the display means  14  includes a driver means  140  and a display module  142 . The driver means  140  interconnects the processor means  12  and the display module  142 . Especially, the driver means  140  connects to the display module  142  through a signal bus  144 . Especially, the signal bus can be replaced by a plurality of signal wire. 
         [0032]    The display module  142  includes an electrode plate  146 , a transparent electrode plate  148  and a plurality of microcapsules  150  positioned between the electrode plate  146  and the transparent electrode panel  148 . The driver means  142  connects to the electrode plate  146  and the transparent electrode panel  148  through the signal bus  144 . 
         [0033]    Each microcapsules includes a transparent fluid  152 , a plurality of positively charged white particle  154  and a plurality of negatively charged black particle  156  respectively positioned inside thereof. The transparent electrode panel  148  of the display module  142  is positioned to face to the transparent plate  234  of the scanning module  214 . 
         [0034]    If the scanning device  200  is operating, the document P is conveyed to pass to the detection means,  10  and then the detection means  10  will detect the color of the document P to send a detection signal to the processor means  12 . The processor means  12  receives and judges the detection signal and then send an indication signal related to the detection signal to the driver means  140 . The driver means is controlled to drive the electrode plate  146  and the transparent electrode plate  148  by the indication signal from the processor. Especially, the driver means  140  sends a driver signal to the electrode plate  146  and the transparent electrode plate  148  through the signal bus  144  for driving the electrode plate  146  and the transparent electrode plate  148 . 
         [0035]    If the color of the document P detected by the detection means  10  is black, the processor means  12  will control the driver means  140  to drive the electrode plate  146  and the transparent electrode plate  148 . Then, the electrode plate  146  will be driven to become positive potential and the transparent electrode plate  148  will be driven to become negative potential. Since, the negatively charged black particles  156  are moved to close to the electrode plate  146  with positive potential, and the positively charged white particle  154  are moved to close to the transparent electrode panel  148  with negative potential. Therefore, the display module  142  of the calibration mechanism  1  will show the document as white color. 
         [0036]    If the color of the document P detected by the detection means  10  is white, the processor means  12  will control the driver means  140  to drive the electrode plate  146  and the transparent electrode plate  148 . Then, the electrode plate  146  is driven to become negative potential and the transparent electrode plate  148  is driven to become positive potential. Since, the positively charged white particles  154  are moved to close to the electrode plate  146  with negative potential, and the negatively charged black particle  156  are moved to close to the transparent electrode panel  148  with positive potential. Therefore, the display module  142  of the calibration mechanism  1  will show the document as the black color. 
         [0037]    Since, the contrast is great enough between the color of the document and the color of the display module  142  of the calibration mechanism  1  for improving de-skew function and edge detection function of the scanning device  200 , and for adjusting shade of the scanning module  214  of the scanning device  200 . Especially, the transparent electrode plate  148  can be replaced by a transparent panel. 
         [0038]    Please refer to  FIG. 5 . A second preferred embodiment of the display means  14  is that the positively charged white particle  154  and the negatively charged black particle  156  are replaced by a Gyricon bead  158 . The Gyricon bead  158  includes a positively charged white hemisphere  160  and a negatively charged black hemisphere  162 . 
         [0039]    If the color of the document P detected by the detection means  10  is black, the processor means  12  will control the driver means  140  to drive the electrode plate  146  and the transparent electrode plate  148 . Then, the electrode plate  146  is driven to become positive potential and the transparent electrode plate  148  is driven to become negative potential. Since, the Gyricon bead  158  is driven to rotate, and then the positively charged white hemisphere  160  is rotated to face the transparent electrode plate  148  with negative potential and the negatively charged black hemisphere  162  is rotated to face the electrode plate  146  with positive potential. 
         [0040]    If the color of the document P detected by the detection means  10  is white, the processor means  12  will control the driver means  140  to drive the electrode plate  146  and the transparent electrode plate  148 . Then, the electrode plate  146  is driven to become negative potential and the transparent electrode plate  148  is driven to become positive potential. 
         [0041]    Since, the Gyricon bead  158  is driven to rotate, and then the positively charged white hemisphere  160  is rotated to face the electrode plate  146  with negative potential and the negatively charged black hemisphere  162  is rotated to face the transparent electrode plate  148  with positive potential. Especially, the microcapsule  150  can be replaced by a accommodating means, the positively charged white particle  154  can be replaced by a positively charged light particle, and the negatively charged black particle  156  can be replaced by a negatively charged dark particle. 
         [0042]    Since, if the document is white, the display module  142  will show it as black. If the document is black, the display module  142  will show it as white. The contrast is great enough between the color of the document and the color of the display module  142  of the calibration mechanism  1  for improving de-skew function and edge detection function of the scanning device  200 , and for adjusting shade of the scanning module  214  of the scanning device  200 . 
         [0043]    Please refer to  FIG. 6 . A second preferred embodiment of the calibration mechanism  1  is that the detection means  10  is replaced by a selection means  16 . The color sensed by the display module  142  of the calibration mechanism  1  will be altered by manually controlling the selection means  16 . Since, the selection means  16  provides a selection to the processor means  14 . The processor means  16  judges the selection signal to control the driver means  142 . Especially, the selection means  16  includes a button, a joystick, a switch, etc, which is positioned on the base  202  or the auto document feeder  204  of the scanning device  200 . 
         [0044]    As described above, the calibration mechanism  1  has simple structure and compact size for conveniently positioned in the scanning device  200 . Furthermore, the calibration mechanism  1  is adapted to a compact scanning device. 
         [0045]    Furthermore, the present invention is not limited to the embodiments described above; diverse additions, alterations and the like may be made within the scope of the present invention by a person skilled in the art. For example, respective embodiments may be appropriately combined.