Abstract:
A scanner optical module has a single transmission axle used to support a scanning module (containing a traditional optical device or CIS). The scanning module has a plurality of protrusions (or rollers) slidably (or rotatably) contacting the transparent document platform (view). The scanner optical module has fewer assembled components, a simpler structure, a decreased material cost and production cost, and is modular.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a scanner optical module, and particularly relates to an improved scanner optical module for simplifying the structure, decreasing the material cost and production cost, and reducing assembled components and increasing assembly efficiency. 
     2. Description of the Related 
     Scanner has gradually become standard equipment for computer users. A computer can read image data from any material scanned by a scanner. The principle of the scanner is very simple; namely a light source shines on a part of a document, and then reflected light is read to get image data of that part of the document. Moreover, the image data can be read into image processing software for retouching. If the document comprises text, the text can be stored as a text file in the computer by character recognition software. 
     The conventional platform scanner uses a conventional optical device, such as a CCD (Charge-Coupled Device), to read the document image. The assembly of the CCD and the lens needs a long optical path, so the volume of the scanner cannot be reduced. Even if using the refraction method to reduce the volume of the scanner by a lens, the reduction level is very limited. In order to reduce the volume of the scanner, a CIS (Contact Image Sensor) is used instead of the CCD. The CIS has already become a CIS module according to the prior art, so all components of the CIS can be installed on the same CIS module. Hence, the CIS module is used with the platform scanner, not only reducing the volume and the weight of the scanner, but also simplifying the inner structure of the scanner and reducing the cost of the assembly and the maintenance. Referring to TW 348875 and TW 350557, the prior art provides a CIS used with the scanner. 
     Furthermore, the transmission axle of the prior art is a dual transmission axle. Hence the structure of the dual transmission axle is very complex, and the material cost of the transmission axle is very expensive. 
     Referring to  FIG. 1 , the CIS scanner  5  of the prior art includes a transparent document platform (windows)  52 , a scanner module  53 , a transmission axle  54 , a plurality of sliding devices  55  and a drive device  56 . The transparent document platform  52  is installed under a machine platform  51  for receiving documents. The scanner module  53  with a CIS  531  is installed under the transparent document platform  52  for reading image data of the documents. The transmission axle  54  is installed under the scanner module  53 , and has two supports  541  installed at two sides thereof and fixed in the machine platform  51  for supporting upwardly the scanner module  53  and attaching tightly the transparent document platform  52  for movement. The sliding devices  55  are installed at two sides of the scanner module  53  and attach tightly to the transparent document platform  52  for reducing friction between the scanner module  53  and the transparent document platform  52 . The drive device  56  connects to the scanner module  53  for driving the scanner module  53  to move from one side to another side of the document. 
     However, the scanner module  53  of the prior art is too complex, so that the scanner module  53  cannot achieve a module function. Furthermore, surface contact occurs between the transmission axle  54  and the scanner module  53  to result in a large friction force, so that the scanner module  53  cannot move smoothly. If abrasion pads installed on the scanner module  53 , the cost thereof will increase. 
     With the employment of unique considerations and application of theories, and based on several years experience in specialized production of all flexible assembly systems and mechanisms, the inventor has come up with an innovative scanner optical module. 
     SUMMARY OF THE INVENTION 
     The main object of the present invention is to provide a scanner optical module. The scanner optical module has some advantages, including fewer assembled components, a simpler structure, decreased material cost and production cost, and module function. 
     Another object of the present invention is to provide a scanner optical module with point contact occurring between the transmission axle and the scanner module for reducing friction between the transmission axle and the sliding groove. 
     In order to achieve the above objects, the present invention provides a scanner optical module, comprising a top cover, a transparent document platform, a scanning module, a transmission axle, a plurality of protrusions and a drive device. 
     The transparent document platform is installed under the top cover for receiving documents. The scanning module is installed under the transparent document platform for reading document image data. The transmission axle is installed under the scanning module, and has two sides fixed into an inner side of the top cover. The protrusions are installed flexibly on the scanning module, and slidably contact the transparent document platform. The drive device is connected to the scanning module for driving the scanning module to move in a scanning direction. 
     In order to achieve the above objects, the present invention provides a scanner optical module, comprising a top cover, a transparent document platform, a scanning module, a transmission axle, a plurality of rollers and a drive device. 
     The transparent document platform is installed under the top cover for receiving documents. The scanning module is installed under the transparent document platform for reading document image data. The transmission axle is installed under the scanning module, and has two sides fixed into an inner side of the top cover. The rollers are installed flexibly on the scanning module, and rotatably contact the transparent document platform. The drive device is connected to the scanning module for driving the scanning module to move along a scanning direction. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. Other advantages and features of the invention will be apparent from the following description, drawings and claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         FIG. 1  is a top view of the scanner of the prior art; 
         FIG. 2  is a front view of the scanner of the prior art; 
         FIG. 3  is a side view of the scanner of the prior art; 
         FIG. 4  is a perspective, exploded view of the scanner optical module of the present invention; 
         FIG. 4A  is a partial perspective view of the scanner CIS module of the present invention; 
         FIG. 5  is another perspective, exploded view of the scanner CIS module of the present invention; 
         FIG. 6  is a perspective, assembled view of the scanner optical module of the present invention; 
         FIG. 7  is a partial schematic view of the scanner optical module according to the first embodiment of the present invention; 
         FIG. 8  is a partial schematic view of the scanner optical module according to the second embodiment of the present invention; 
         FIG. 9  is a partial schematic view of the scanner optical module according to the third embodiment of the present invention; 
         FIG. 10  is a partial schematic view of the scanner optical module according to the fourth embodiment of the present invention; 
         FIG. 11  is a perspective, exploded view of the elastic element and the scanner module of the present invention; 
         FIG. 12  is another perspective, exploded view of the elastic element and the scanner module of the present invention; 
         FIG. 13  is a perspective, exploded view according to another embodiment (Scanner Optical module) of the present invention; 
         FIG. 14  is a perspective, assembled view according to another embodiment (Scanner Optical module) of the present invention; 
         FIG. 15  is a perspective, assembled view according to another embodiment of the scanner module and the drive device of the present invention; 
         FIG. 16  is a perspective, assembled view according to another embodiment of the scanner optical module of the present invention; 
         FIG. 17  is a perspective, exploded view according to another embodiment of the roller of the present invention; and 
         FIG. 18  is a perspective, assembled view according to another embodiment of the roller of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to  FIGS. 2 and 6 , the present invention provides a scanner optical module, including a top cover  11 , a transparent document platform (windows)  12 , a scanning module  13 , a transmission axle  14 , two elastic elements  16  and a drive device  17 . The transparent document platform  12  is made of transparent material like glass, and is installed under the top cover  11  for receiving documents. 
     The scanning module  13  is installed movably in the top cover  11  and under the transparent document platform  12  for reading image data. The scanning module  13  has a support  131 , and a CIS  132  installed on the support  131 . The CIS  132  has includes a light source, lens and a photoelectric transforming device (not shown), thus forming a module design. The scanning module  13  has a sliding groove  133  arranged on a bottom side and middle portion of the support  131 . The sliding groove  133  is an almost completely covered hollow groove with multiple contact points (as shown in  FIG. 4A ), or a half-covered hollow groove with a U-shape (as shown in  FIGS. 7-10 ). 
     The transmission axle  14  is installed under a center of the scanning module  13 , and has an idle wheel support  141  arranged at one side thereof and a transmission support  142  arranged at the other side thereof and fixed in the top cover  11 . The scanning module  13  slides on the transmission axle  14  by the sliding groove  13 . The transmission axle  14  supports upwardly the scanning module  13 , and the scanning module  13  attaches tightly the transparent document platform  12  for movement. The sliding groove  133  has an inner wall that can be changed into many different shapes to form multiple contact points  1331  (as shown in FIGS.  4 A and  7 - 9 ) for resulting point contact between the sliding groove  133  and the transmission axle  14 . In another embodiment, the sliding groove with an oval shape contacts the transmission axle  14  to form two points of tangency (as in  FIG. 10 ). The sliding groove  133  has two concave oil storage tanks  1332  formed near the two points of tangency, respectively. In other words, the sliding groove  133  has two concave oil storage tanks  1332  formed between the sliding groove  133  and the transmission axle  14  to store the lubricant for self-lubrication of the scanner optical module. 
     The two elastic elements  16  are made of elastic material, and each have a fixed portion  161  and an elastic arm  162  (as shown in  FIGS. 11 and 12 ). The fixed portion  161  with an L-shape has two protrusions  164  extending from a top side thereof, and attaches tightly to the transparent document platform  12  to allow the two protrusions  164  to contact slidably the transparent document platform  12  with multiple contact points. The elastic arm  162  is integrally connected to the fixed portion  161 , and extends downwardly along an inclined direction. Screws fasten the two fixed portions  161  of the two elastic elements  16  on two sides of the CIS  132  of the scanning module  13 , respectively. The two elastic arms  162  of the two elastic elements  16  are extended slantwise under a bottom side of the CIS  132 , so the two elastic arms  162  contact a bottom side of the support  131  for pushing the CIS  132  to move vertically. The protrusions  164  are arranged on the scanning module  13  to attach the CIS  132  tightly to the transparent document platform  12  for movement to absorb the tolerance. Each of the fixed portions  161  has an elastic hook  163  hooked on one side of the support  131  of the scanning module  13  for positioning. 
     The drive device  17  has a driver stepping motor  171 , a speed reducing gear set  172  and a transmission element  173 . The driver stepping motor  171  and the speed reducing gear set  172  are used to drive the transmission support  142  to fix into an inner side of the top cover  11 . The transmission element  173  is a flexible transmission element, such as a timing belt. The driver stepping motor  171  connects to the transmission element  173  through the speed reducing gear set  172 . The transmission element  173  is fixed on a connected portion  137  of the scanning module  13  to allow the drive device  17  to connect to the scanning module  13 . Power from the driver stepping motor  171  is transmitted to the transmission element  173  through the speed reducing gear set  172  and drives the scanning module  13  to move from one side of the document to the other side of the document to scan the document. 
       FIGS. 13 to 18  illustrate another embodiment of the present invention. The scanning module (will be a traditional optical scanner system to replace CIS module)  13  has three receiving grooves  134  formed at two sides and a middle side thereof, respectively. The scanning module  13  has three rollers  15  installed in the three receiving grooves  134 , respectively. Each of the receiving grooves  134  has a closed first pivot hole  135  formed at in one side thereof, and an open second pivot hole  136  formed in the other side thereof for assembly. The scanning module  13  further has three elastic pivots  151 , each installed through an axle center of the roller  15 . Each of the elastic pivots  151  has two sides; one side of the elastic pivot  151  is installed in the first pivot hole  135 , and the other side is installed in the second pivot hole  136 . Each of the rollers  15  rotatably contact the transparent document platform  12  by three contact points for reducing the friction coefficient between the scanning module  13  and the transparent document platform  12 . The rollers  15  are installed flexibly at the two sides and the middle side of the scanning module  13 , so the scanning module  13  can attach tightly to the transparent document platform  12  to move for absorbing the tolerance and balancing the movement of the scanning module  13 . 
     To sum up, the scanner optical module of the present invention includes some advantages, including: 
     1. The transmission axle  14  is a single transmission axle for ensuring that the movement of the scanning module  13  is balanced. 
     2. The scanning module  13  has protrusions  164  and rollers  15  used to balance the scanning module  13  for increasing the scanning quality and holding the scanning module  13  to allow smooth movement. 
     3. The point contact occurs between the transmission axle  14  and the scanning module  13  for reducing the friction force between the transmission axle  14  and the sliding groove  133 . The sliding groove  133  has two concave oil storage tanks  1332  formed between the sliding groove  133  and the transmission axle  14  to store lubricant for self-lubrication of the scanner optical module. 
     4. The scanning module  13  has elastic elements  16  (or elastic pivots  151 ) for attaching the protrusions  164  (or rollers  15 ) of the scanning module  13  flexibly and tightly to the transparent document platform  12 , thus allow movement for absorbing the tolerance. Even if the present invention has some error in assembly or the top cover  11  is somewhat changed in shape, the scanning module  13  attaches tightly to transparent document platform  12 . When scanning module  13  moves on the transmission axle  14 , the distance between the scanning module  13  and transmission axle  14  is predetermined for holding the document within a predetermined depth of field, thus ensuring the quality of the image. 
     5. All of the components can be assembled on the top cover  11 . Hence, if the present invention is turned over for anything, the components do not separate from the top cover  11  for achieving the module function, and may be conveniently assembled on any other device. 
     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 modification 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.