Abstract:
An optical image and transmission composite assembly comprises an optical module, a transmission unit and a guiding unit. The transmission unit and the guiding unit are arranged on the optical module, wherein the optical module is guided and moved by the engagement of a plurality of wheels and tooth bars, or by a female guiding stage and a male guiding stage fit with the female guiding stage. The assembling effort and cost of the scanner using the optical image and transmission composite assembly can be reduced.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to an optical image and transmission composite assembly, especially to an image-input optical module provided with transmission unit for transmitting and guiding functions, thus modularizing the optical module and the transmission unit, and reducing cost.  
         BACKGROUND OF THE INVENTION  
         [0002]    The flat bed image scanners are popular computer peripheral for scanning the text, chart or graphic from book or magazine into computer accessible data. The prior art flat bed image scanners generally comprise an image input means, a transmission unit, an image processing circuit, a transparent scanning window and a shell. The transmission unit occupies considerable space in the flat bed image scanner. Therefore, the improvement of transmission unit is important design issues for the flat bed image scanners.  
           [0003]    As shown in FIG. 1, a prior art image input means  1   a  generally comprises a light source, a reflection mirror set, a lens, and an image sensor (not shown). The transmission unit  2   a  generally comprises a stepper motor  20   a,  a wheel set  21   a,  a idler wheel  22   a,  a timing belt  23   a  and a sliding shaft  24   a.    
           [0004]    The operation principle of the flat bed image scanner is described as follows. The document to be scanned is placed atop the transparent scanning window and then illuminated by the light source of the image input means  1   a . The reflected light from the document is then guided to the image sensor (not shown) by the reflection mirror set and the lens (both not shown). The image sensor generates electrical signal corresponding to the received light and then sends the signal to the image processing circuit to digitize. After the image sensor (not shown) finishes scanning one row of image, the transmission unit  2   a  moves the image input means  1   a  next region to be scanned. Repeat said processes until all area of document has been scanned.  
           [0005]    Moreover, as shown in FIG. 1, the stepper motor  20   a  and the wheel set  21   a  of the transmission unit  2   a  are retained on the shell of the flat bed image scanner. The wheel set  21   a  is located at one end of the timing belt  23   a  and driven by the timing belt  23   a  such that the image input means  1   a  is sliding along the sliding shaft  24   a  to complete the image scanning.  
           [0006]    However, in above-mentioned flat bed image scanner, the image input means  1   a  and the transmission unit  2   a  are separately arranged and the transmission unit  2   a  are retained on the shell of the flat bed image scanner. Therefore, considerable space is wasted. Moreover, the flat bed image scanner is hard to disassemble and assemble.  
         SUMMARY OF THE INVENTION  
         [0007]    It is the object of the present invention to provide an optical image and transmission composite assembly wherein the optical module is provided with transmission unit for transmitting and guiding functions, thus modularizing the optical module and the transmission unit, and reducing cost.  
           [0008]    To achieve above object, the present invention provides an optical image and transmission composite assembly for a scanner. The optical image and transmission composite assembly comprises an optical module, a transmission unit and a guiding unit. The optical module has a light source, a reflection mirror set, a lens and an image sensor. The transmission unit has a stepper motor and is arranged on the optical module. The stepper motor has a driving wheel engaged to a first driven wheel and the first driven wheel is engaged to a tooth bar. The guiding unit has a second driven wheel engaged to the first driven wheel and also engaged to another tooth bar.  
           [0009]    In another aspect of the invention, the guiding unit has a female guiding stage and a male guiding stage fit with the female guiding stage, and is functioned to guide the optical module.  
           [0010]    The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: 
       
    
    
     BRIEF DESCRIPTION OF DRAWING  
       [0011]    [0011]FIG. 1 shows the perspective view of a prior art image input means and a prior art transmission unit;  
         [0012]    [0012]FIG. 2 shows the explosive view of the scanner of present invention;  
         [0013]    [0013]FIG. 3 shows the explosive view of the first preferred embodiment of the present invention;  
         [0014]    [0014]FIG. 4 shows the perspective view of the first preferred embodiment of the present invention;  
         [0015]    [0015]FIG. 5 shows the transmission unit and the guiding unit of the first preferred embodiment of the present invention;  
         [0016]    [0016]FIG. 6 shows the transmission operation of the first preferred embodiment of the present invention;  
         [0017]    [0017]FIG. 7 shows the explosive view of the second preferred embodiment of the present invention;  
         [0018]    [0018]FIG. 8 shows the perspective view of the second preferred embodiment of the present invention;  
         [0019]    [0019]FIG. 9 shows the transmission unit and the guiding unit of the second preferred embodiment of the present invention;  
         [0020]    [0020]FIG. 10 shows the transmission operation of the second preferred embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]    [0021]FIG. 2 shows the explosive view of the present invention; the scanner according to the present invention comprises a base  1 , an optical image and transmission composite assembly  2 , an image processing circuit (not shown), a transparent scanning window  3 , a shell  4  and a top cover  5 . In the present invention, the image input optical module and the transmission unit are integrated to form an image input optical and transmission composite module  2 .  
         [0022]    [0022]FIGS. 3 and 4 show the explosive and perspective views of the first preferred embodiment of the present invention, respectively. The optical image and transmission composite assembly  2  comprises an optical module  20  and a transmission unit  21  and a guiding unit  22 , which are arranged on one side or both sides of the optical module  20 , as shown in FIG. 5.  
         [0023]    The optical module  20  comprises a light source, a reflection mirror set, a lens and an image sensor (not shown), and a resilient member  200  on both bottom lateral sides of the optical module  20 . The resilient members  200  are rested against the projecting rail (not shown) on the base  1 . The optical module  20  also has resilient member (not shown) on topside thereof. The resilient member  200  moves along the transparent scanning window  3  and the base  1  such that the structure of the optical module is stable. The optical module  20  has similar structure as that of prior art and is not described in detail here.  
         [0024]    The transmission unit  21  comprises a stepper motor  210  arranged on the optical module  20  and the stepper motor  210  is connected to a driving wheel  211 , which is engaged with two first driven wheels  212  aligned in Y-direction. Moreover, the two first driven wheels  212  are engaged to a tooth bar  213  extended in Y-direction as shown in FIG. 5. Moreover, the guiding unit  22  has two second driven wheels  220  aligned in Y-direction and engaged to the two first driven wheels  212  in X-direction. Moreover, the two second driven wheels  220  are engaged to a tooth bar  221  extended in Y-direction as shown in FIG. 5. As shown in FIG. 6, the two first driven wheels  212  are linked to the tooth bar  213  and the two second driven wheels  220  are linked the tooth bar  221 , thus enabling the optical module  20  in shuttle motion and guiding the optical module  20 . Moreover, one of the second driven wheel  220  and the tooth bar  221  has resilient member (not shown) to provide translational tolerance. The overall structure of the optical image and transmission composite assembly  2  has lateral balance.  
         [0025]    [0025]FIGS. 7 and 8 show the explosive and perspective views of the second preferred embodiment of the present invention, respectively. The optical image and transmission composite assembly  2  comprises an optical module  20  and a transmission unit  21 , which are arranged on one side or both sides of the optical module  20 , and a guiding unit  22  arranged on center of the optical module  20 .  
         [0026]    The optical module  20  comprises a light source, a reflection mirror set, a lens and an image sensor (not shown), and a resilient member  200  on bottom side of the optical module  20 . The optical module  20  also has resilient member (not shown) on topside thereof. The resilient member  200  moves along the transparent scanning window  3  and the base  1  such that the optical module has stable structure. The optical module  20  has similar structure as that of prior art and is not described in detail here.  
         [0027]    The transmission unit  21  comprises a stepper motor  210  arranged on the optical module  20  and the stepper motor  210  is connected to a driving wheel  211 , which is engaged with two first driven wheels  212  aligned in Y-direction. Moreover, the two first driven wheels  212  are engaged to a tooth bar  213  extended in Y-direction as shown in FIG. 9. As shown in FIG. 10, the two first driven wheels  212  are linked to the tooth bar  213 , thus enabling the optical module  20  in shuttle motion and guiding the optical module  20 .  
         [0028]    Moreover, the guiding unit  22  has a female guiding stage  222  and a male guiding stage  224  fit with the female guiding stage  222 . The female guiding stage  222  is composed of a U-shaped groove  2220  and two bottom plates  2221  extended inwardly from both sides of the U-shaped groove  2220 . A plurality of retractable wheels  223  is provided between the two bottom plates  2221  and the top plate  2222 . Due to the flexibility of the retractable wheels  223 , the overall structure of the optical image and transmission composite assembly  2  has lateral balance. Moreover, a resilient member  200  is provided through center of the top plate  2222 .The male guiding stage  224  has a top surface  2240  and two lateral walls  2241  extended downward from both sides of the top surface  2240 . The top surface  2240  is functioned as the sliding rail of the resilient member  200  and the two lateral walls  2241  provide clamping force to the retractable wheels  223  such that the optical module  20  has guided movement.  
         [0029]    To sum up, the image-input optical and transmission composite assembly of the present invention has following advantages:  
         [0030]    (1) Modularized design: integrating the image input means and the transmission unit into a single module.  
         [0031]    (2) No transmission belt: directly engaging the transmission unit on the optical module to the tooth bar inject molding on the bottom cover to eliminate the use of transmission belt.  
         [0032]    (3) No sliding shaft: the resilient member arranged on the optical module providing horizontal and vertical balance for the optical module, thus eliminating the use of sliding shaft.  
         [0033]    (4) Easy maintenance: the design and structure of the image-input optical and transmission composite assembly having easy maintenance advantage.  
         [0034]    (5) Optimized volume: the transmission unit directly mounted on the optical module and circuit board can be mounted on lateral space of the optical module to optimized space usage.  
         [0035]    Although the present invention has been described with reference to the preferred embodiment thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have suggested in the foregoing description, and other will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.