Abstract:
An optical scanning module disposed in a scanning apparatus for acquiring an image of a document is disclosed. The optical scanning module comprises an light-sensing component, for sensing a light signal of the document and converting the light signal to an analog image signal; a front end processor, coupled to the light-sensing component for receiving and converting the I analog image signal to a digital image signal; and an application specific integrated circuit, for receiving and processing the digital image signal, and outputting an processed digital image signal.

Description:
[0001]     This application claims the benefit of Taiwan application Serial No. 94115685, filed May 13, 2005, the subject matter of which is incorporated herein by reference.  
       BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The invention relates in general to a scanning apparatus, and more particularly to a scanning apparatus that integrates a light-sensing component, an analog front end processor and an application specific integrated circuit (ASIC) into the optical scanning module.  
         [0004]     2. Description of the Related Art  
         [0005]     Referring to  FIG. 1 , a block diagram illustrating a conventional scanner is shown. The conventional scanner includes an optical scanning module  110  and a main board  150  fixed on the body of the scanner. The optical scanning module  110  includes a charge couple device (CCD) module  115  for detecting a light signal. An application specific integrated circuit (ASIC)  151  and an analog front end (AFE) processor  153  are arranged and disposed on the main board  150 , for controlling the charge couple device module  115 , and receiving the light signal and converting the light signal to the digital form, respectively.  
         [0006]     During scanning, the optical scanning module  110  of the scanner moves relatively with the to-be-scanned document, and the charge couple device module  115  simultaneously detects the light signal, which is reflected or transmitted from the to-be-scanned document. The light signal converts to the light analog signal RGB. After the charge couple device module  115  detects the light signal, the application specific integrated circuit  151  obtains the light analog signal RGB in accordance with the control signal (CTRL), and then proceeds the following procedures of image processing. Especially, the light analog signal RGB can not be processed digitally, so that the light analog signal RGB is converted to a digital form by the analog front end processor  153 . Afterward, the light digital signal is transmitted through the BUS to the application specific integrated circuit  151  through the BUS for the following image processing.  
         [0007]     Additionally, when the scanner is a flatbed scanner, the drive motor  155  is disposed on the scanner. The drive motor  155  controls the movement of the optical scanning module  110  according to the command, which is transmitted from the application specific integrated circuit  151 , such as the specific start-stop movement of the scanner.  
         [0008]     Also, a memory  157  is disposed on the main board  150 . The memory  157  is a data buffer for storing scanning data temporarily.  
         [0009]     In the practical operation, since the analog front end processor  153  and application specific integrated circuit  151  are both disposed on the main board  150 , there are numerous connecting lines between the main board  150  and the optical scanning module  110 . In addition to three light signal lines (each of which is for transmitting one of the three primary color (RGB) signals), the various signals, such as the φ1 and φ2 signals, the reset signal, the power signal, and the grounding signal (GND) of the CCD control signal (CTRL) are further included. Please referring to  FIG. 2 , a layout illustrating a charge couple device module (CCD) manufactured by Sony Inc. The CCD product of Sony, commercially named as ILX558K, requires twelve input/output pins and the numerous signal lines in the circuit connection, resulting in the high manufacture cost. Furthermore, the light analog signal RGB transmitted from the charge couple device module  115  to the main board  150  is easily to be suffered from the electromagnetic interference (EMI). The light analog signal RGB maybe produces distortion due to the electromagnetic interference. So, the quality of the scanned image will be reduced.  
       SUMMARY OF THE INVENTION  
       [0010]     It is therefore an object of the invention to provide a scanning apparatus. The scanning apparatus can reduce the number of the signal lines and shorten the length of the signal lines. Besides, the EMI caused by the signal lines are reduced significantly when the data is transmitted.  
         [0011]     The invention achieves the above-identified object by providing an optical scanning module disposed in a scanning apparatus for acquiring an image of a document. The optical scanning module comprises a light-sensing component, a front end processor, and an application specific integrated circuit. The light-sensing component for sensing a light signal of the document and converting the light signal to an analog image signal; the front end processor, coupled to the light-sensing component for receiving the analog image signal and converting the analog image signal to a digital image signal; and an application specific integrated circuit, for receiving and processing the digital image signal, and outputting a processed digital image signal.  
         [0012]     The invention also achieves the above-identified object by providing a scanning apparatus. The scanning apparatus is electrically connected to a controlling device, wherein the controlling device controls the scanning apparatus for proceeding the scanning procedures. The scanning apparatus comprises a main body, and an optical scanning module. The optical scanning module includes a light-sensing component, a front end processor, and an application specific integrated circuit. The optical scanning module is disposed in the main body for acquiring an image of a document. The light-sensing component is used for sensing a light signal of the document and converting the light signal to an analog image signal; the front end processor is coupled to the light-sensing component for receiving the analog image signal and converting the analog image signal to a digital image signal; and the application specific integrated circuit is used for receiving and processing the digital image signal, and transmitting an processed digital image signal to the controlling device.  
         [0013]     Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The following description is made with reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]      FIG. 1  (Prior Art) shows a block diagram illustrating a conventional scanner.  
         [0015]      FIG. 2  (Prior Art) is a layout illustrating a charge couple device module (CCD) manufactured by Sony Inc.  
         [0016]      FIG. 3  schematically shows a scanning apparatus in the first embodiment of the present invention.  
         [0017]      FIG. 4  is a block diagram showing the scanning apparatus of  FIG. 3  disposed on a circuit board.  
         [0018]      FIG. 5  schematically shows a scanning apparatus in the second embodiment of the present invention.  
         [0019]      FIG. 6  schematically shows a scanning apparatus in the third embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
     First Embodiment  
       [0020]      FIG. 3  schematically shows a scanning apparatus in the first embodiment of the present invention. The scanning apparatus  200  includes a main body  201  and an optical scanning module  204 . The optical scanning module  204  is disposed in the main body  201 . The optical scanning module  204  proceeds the scanning procedures under the control by the controlling device  220 . The controlling device  220  could be a processor built in the scanning apparatus  200 , or an external computer. A circuit board  212  disposed on the optical scanning module  204  is electrically connected to the controlling device  220  via the signal line  210 .  
         [0021]      FIG. 4  is a block diagram showing the scanning apparatus of  FIG. 3  disposed on a circuit board. A light-sensing component  214 , a front end processor  216 , an application specific integrated circuit (ASIC)  218  and a drive motor  222  are disposed on the circuit board  212 . The light-sensing component  214  detects the light signal reflected from the document or transmitted the document, and then converts the light signal into an analog image signal RGB. Examples of the light-sensing component  214  include a charge couple device (CCD) or a complementary metal oxide semiconductor (CMOS). The front end processor  216  has an analog front end device  216   a  and a signal generator  216   b . The analog front end device  216   a  is coupled to a light-sensing component  214  for converting the analog image signal RGB into the digital image signal DOS. The signal generator  216   b  is coupled to the light-sensing component  214  and the analog front end device  216 a, for generating a control signal CTRL and an analog front end control signal CS′. The light-sensing component  214  outputs each pixel corresponding to the analog image signal RGB sequentially under the control of the control signal CTRL. The analog front end device  216   a  uses the analog front end control signal CS′ as the clock signal to convert the analog image signal RGB to the digital image signal DOS′.  
         [0022]     Please refer to both  FIG. 3  and  FIG. 4 . The application specific integrated circuit  218  is used to process the digital image signal DOS′ and to receive the image transmitting control signal (not shown in the figures) from the controlling device  220 . The digital image signal DOS′ is then transmitted to the controlling device  220 . The application specific integrated circuit  218  transmit command to the front end processor  216  via a command interface CMD, allowing the front end processor  216  for image capturing, signal conversion, and data feedback (for example, looking into the table according to the command or making the communication protocol between the front end processor  216  and application specific integrated circuit  218 ).  
         [0023]     The drive motor  222  is also disposed in the scanning apparatus  200 . The gears of the output end of the drive motor  222  (not shown in the figures), engaged with the belt (not shown) which is secured on the main body  201 , are used to drive the optical scanning module  204  to move. The drive motor  222  is controlled by the application specific integrated circuit (ASIC)  218 . The motor synchronous signal MSYNC is generated from the optical scanning module  204  according to the practical scanning situation, and the action of the drive motor  222  and the scanning procedure can be operated in coordination accurately.  
         [0024]     Also, the circuit board  212  receives the power source for scanning via a power line  224 , as shown in  FIG. 3 . The scanning apparatus  200  further includes a first transmission interface  208   a , the circuit board  212  outputs the digital image signal DOS′ to a second transmission interface  208   b  of the controlling device  220  via the first transmission interface  208   a . The first transmission interface  208   a  and the second transmission interface  208   b  are compatible with a serial transmission interface standard, such as RS-232, USB or IEEE 1394 interface.  
       Second Embodiment  
       [0025]      FIG. 5  schematically shows a scanning apparatus in the second embodiment of the present invention. The scanning apparatus  500  includes a main body  201 , an optical scanning module  204 , a power supply  206  and a bridge board  250 . The power supply  206  disposed on the main body  201  is used to provide the power source for driving the optical scanning module  204 . The optical scanning module  204  disposed on the main body  201  is used to implement the scanning procedure under the control of the controlling device  220 . The bridge board is connected to a interface of the scanning apparatus  200 . The optical scanning module  204  is electrically connected to the controlling device  220  via the bridge board  250  and the signal line  210 . The bridge board  250 , electrically connected to the optical scanning module  204  and the controlling device  220 , could be RS-232, USB or IEEE 1394 interface.  
       Third Embodiment  
       [0026]      FIG. 6  schematically shows a scanning apparatus in the third embodiment of the present invention. Similar to the first and second embodiments, the scanning apparatus  200  includes an optical scanning module  204 , a power supply  206  and a main body  201 . However, the difference between the third embodiment and above-mentioned embodiments is the electronic components such as the light-sensing component, the front end processor and the application specific integrated circuit can be disposed in the integrated area  217  and electrically connected to the circuit board  212 . The integrated area  217  may be a circuit board or just a flat board for disposing those electronic components. Besides, the circuit board  212  connected to the controlling device can achieve the same result.  
         [0027]     According to the aforementioned description, by integrating the light-sensing component, the front end processor, the application specific integrated circuit and the drive motor in the same optical scanning module, the conventional bus lines for communicating the main board with the optical scanning module can be omitted. Therefore, the number of the signal lines is reduced. For example, the digital image signal DOS′ is processed by the circuit board  212 , and transmitted to the controlling device  220  directly with less EMI disturbance caused by the bus lines. Hence, the quality of the scanned image can be effectively improved.  
         [0028]     While the invention has been describe includes ad by way of examples and in terms of preferred embodiments, it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.