Patent Publication Number: US-2005128537-A1

Title: Carrying apparatus for holding optical scanning module

Description:
This application claims the benefit of Taiwan application Serial No. 92135089, filed Dec. 11, 2003, the subject matter of which is incorporated herein by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The invention relates in general to a carrying apparatus for holding optical scanning module, and more particularly to the carrying apparatus having an adjusting means for adjusting the position of the optical scanning module, so as to lift the optical scanning module up and against the platen during the scanning operation.  
      2. Description of the Related Art  
      In the age of high technology, scanner has been required in the modern life due to its great functions of scanning the original drafts, such as the pictures, the photos and the documents, and then transforming and saving the image as the digital files. It provides a very convenient way for the users to keep or find the original drafts. The mechanical devices contained in the scanner are briefly described below.  
      A conventional optical scanner has a transparent platen for placing an original to be scanned document. A moving carriage assembly and the drive mechanisms are positioned underneath the transparent platen. The moving carriage assembly, including an optical scanning module supported by a carrying apparatus (also called “carriage” hereinafter), contains the optical and electronic or reflective components, and moves across the complete length of the document during scanning. The components commonly used for the carriage assembly are the light source, the reflector, the lens and the photo-electronic sensing device. Drive mechanisms for moving the carriage assembly are varied. During scanning, the light emitted from the light source is reflected by the original to be scanned document, and then further reflected by the lens and focused on the photo-electronic sensing device by the lens. Afterward, the light signal received by the photo-electronic sensing device is converted into electronic signals, and then produce machine-readable data, which is representative of the image of the original document. The photo-electronic sensing device can be any device capable of converting the light signal into the electric signal, such as charged coupled device (CCD) or contact image device (CIS).  
      During scanning, the carriage assembly is required to move against the transparent platen, particularly the carriage assembly using contact image device (CIS) (which has a short scene depth of about 0.3 mm) as the photo-electronic sensing device.  FIG. 1  is an explosive view schematically showing a conventional structure of the contact image device (CIS) module and the carrying apparatus. The transparent platen  1  is used for placing an original to be scanned document. Under the transparent platen  1 , the optical scanning module  2  is loaded in the carriage  4  which is positioned on a shaft (not shown) by a connecting means  6 , and the drive mechanism (not shown) drives the carriage  4  to move along the scanning direction on the shaft. Also, a spring  8  is interposed between the optical scanning module  2  and the carriage  14 . The spring  8  provides an upward elastic force to lift the optical scanning module  2  up until contacting the bottom surface of the transparent platen  1 , thereby making the optical scanning module  2  moving against the transparent platen  1  during scanning operation.  
      As be known, the degree of fidelity with which the information presented by the to be scanned document is recorded depends on the accuracy with which the moving carriage assembly is guided during the scanning operation. The reproduction is liable to be impaired even by small changes in either the direction of relative scanning movement or the spacing between the document and the optical scanning module  2  from one moment to another in the scanning operation. The conventional design with a spring  18  between the scanning apparatus and the carriage, however, is difficult to keep the optical scanning module  2  in balance, particularly in a scanning movement. It is also difficult to precisely and firmly locate the spring  18  at the center of the carriage  4 . In practice it would be desirable to design not only an easy to be assembled but also a more reliable and stable structure to lift the scanning module up for contacting with the platen, thereby obtaining an optimal scanning image result with a high standard of accuracy.  
     SUMMARY OF THE INVENTION  
      It is therefore an object of the invention to provide a carrying apparatus for holding the optical scanning module. The carrying apparatus having an adjusting means generates an upward force to rotate the carriages, thereby lifting the optical scanning module up and against the platen during the scanning operation.  
      The invention achieves the objects by providing an adjusting means disposed on a carrying apparatus for holding an optical scanning module. The adjusting means comprises a first coupling portion, formed on a first carriage of the carrying apparatus; a second coupling portion, formed on a second carriage of the carrying apparatus, and the first coupling portion and the second coupling portion are pivotably connected; and an elastic device, connected to at least one of the first carriage and the second carriage, for providing an elastic force to make the first carriage and the second carriage rotate relatively. The elastic device could be the plate spring, torsion spring, or the idle pulley apparatus having an elastic force.  
      According to the object of the invention, a carrying apparatus disposed in a scanner for holding an optical scanning module is provided. The carrying apparatus at least comprises a first carriage; a second carriage pivotably connected to the first carriage; and a carriage control means, providing an upward supporting force to the fist carriage, thereby lifting the optical scanning module upward and against the platen during a scanning operation. The carriage control means could be the plate spring, torsion spring, or the idle pulley apparatus having an elastic force.  
      According to the object of the invention, a scanner capable of adjusting the position of the optical scanning module is further provided. The scanner comprises a platen for placing a to-be-scanned document; an optical scanning module, disposed under the platen for scanning and acquiring an scanned image of the to-be-scanned document; and a carrying apparatus for holding the optical scanning module and moving backward and forward in the scanner. The carrying apparatus at least comprises a first carriage; a second carriage, pivotably connected to the first carriage; and a carriage control means, providing an upward supporting force to the fist carriage, thereby lifting the optical scanning module upward and against the platen during a scanning operation.  
      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  
       FIG. 1  (prior art) is an explosive view schematically showing a conventional structure of the contact image device (CIS) module and the carrying apparatus;  
       FIG. 2A  schematically illustrates a disassembled view of the carrying apparatus and the optical scanning module according to the first embodiment of the invention;  
       FIG. 2B  schematically illustrates a bottom view of the assembled carrying apparatus of  FIG. 2A ;  
       FIG. 2C  is an enlarged view of an adjusting means shown in  FIG. 2B ;  
       FIG. 2D  is a cross-sectional diagrammatic side view of the optical scanning module loaded into the carrying apparatus of  FIG. 2A ;  
       FIG. 3A  schematically illustrates a disassembled view of the carrying apparatus and the optical scanning module according to the second embodiment of the invention;  
       FIG. 3B  is an enlarged bottom view of an adjusting means of the assembled carrying apparatus of  FIG. 3A ;  
       FIG. 4  schematically illustrates a disassembled view of the carrying apparatus and the optical scanning module according to the third embodiment of the invention; and  
       FIG. 5  schematically illustrates a disassembled view of the carrying apparatus and the optical scanning module according to the fourth embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      In the present invention, a carrying apparatus for holding the optical scanning module is mechanically constructed by using an adjusting means having the carriage control means. Two carriages pivotably connected are rotated upward by the carriage control means, thereby lifting the optical scanning module up and against the transparent platen. The carriage control means disclosed in the embodiments includes a plate spring, a torsion spring and an idle pulley apparatus having idle pulley spring. The detail structures of the adjusting means in the embodiments are slightly different and constructed according to the carriage control means in use.  
      There are four embodiments disclosed herein for illustrating the invention, but not for limiting the scope of the invention. Additionally, the drawings used for illustrating the embodiments of the invention only show the major characteristic parts in order to avoid obscuring the invention. Accordingly, the specification and the drawing are to be regard as an illustrative sense rather than a restrictive sense.  
      First Embodiment  
       FIG. 2A  schematically illustrates a disassembled view of the carrying apparatus and the optical scanning module according to the first embodiment of the invention. In a scanner, the carriage (carrying apparatus)  10  is provided for carrying the optical scanning module  20 . The carrying apparatus  10  includes the first carriage such as a carriage-left (carriage-L)  11 , the second carriage such as a carriage base  12 , and the third carriage such as a carriage-right (carriage-R)  13 . The carriage-L  11  and the carriage-R  13  are rotatably connected to the ends of the carriage base  12  by the adjusting means  14   b  and  14   a , respectively. Also, by mounting the groove  122  (formed on the bottom surface of the carriage base  12  and having a half-circular cross section) on the guiding shaft (not shown in  FIG. 2A ), the carrying apparatus  10  is capable of being moved backward and forward along the scanning direction.  
      For example, the adjusting means  14   a  includes a torsion spring  142   a , and a rotation part comprising a first coupling portion  144   a , a second coupling portion  146   a  and an axial rod  148   a . Noted that the torsion spring  142   a  is used as a carriage control means in the first embodiment. During assembling, the axial rod  148   a  inserts through the holes of the first coupling portion  144   a , the second coupling portion  146   a  and the curly part of the torsion spring  142   a . The adjusting means  14   b  and  14   a  are symmetrically arranged on the carrying apparatus  10 ; also, both of them have the same mechanical components.  
       FIG. 2B  schematically illustrates a bottom view of the assembled carrying apparatus of  FIG. 2A .  FIG. 2C  is an enlarged view of an adjusting means shown in  FIG. 2B . After assembling, the torsion spring  142   a  mounting on the axial rod  148   a  touches the carriage base  12  and carriage-R  13  by two ends (i.e. the carriage base  12  and carriage-R  13  are subjected to the elastic force of the torsion spring  142   a ), so that a relative rotation between the carriage-R  13  and the carriage base  12  is generated. The function of the torsion spring  142   b  is similar to that of the spring  142   a . The torsion spring  142   b  mounting on the axial rod  148   b  touches the carriage base  12  and carriage-L  11  by two ends (i.e. the carriage base  12  and carriage-L  11  are subjected to the elastic force of the torsion spring  142   b ), so as to make a relative rotation between the carriage-L  11  and the carriage base  12 .  
       FIG. 2D  is a cross-sectional diagrammatic side view of the optical scanning module loaded into the carrying apparatus of  FIG. 2A . When the optical scanning module  20  is loaded into the carrying apparatus, the carriage-L  11  and the carriage-R  13  assembled on the both sides of the carriage base  12  will be forced to moved upward due to the torsions of the torsion springs  14   b  and  14   a , thereby lifting the optical scanning module  20  up and against the transparent platen  30 .  
      A fixing means could be further used for maintaining the position of the optical scanning module  20  on the carrying apparatus  10 . As shown in  FIG. 2A , the optical scanning module  20  has a housing  22  for protecting the image-capture components  24  (such as the light source and the photo-electronic sensing device). The ribs  220   a  and  220   b  are formed on the housing  22  of the optical scanning module  20 , and the notches  120   a  and  120   b  are relatively configured on the sidewall of the carriage base  12 . When the optical scanning module  20  is loaded into the carrying apparatus  10 , the ribs  220   a  and  220   b  insert into the notches  120   a  and  120   b , respectively, for preventing the slide of the optical scanning module  20 .  
      It is, of course, understood that a number of the ribs and the notches (or only one set of the rib and the notch) could be configured without interfering the movement of the carrying apparatus  10 , and the locations of the ribs and the notches could be exchanged (i.e. the ribs and the notches respectively formed on the carriage base  12  and the housing  22 ) for maintaining the position of the optical scanning module  20 . Other types of fixing means could be used to maintaining the position of the optical scanning module  20 , too.  
      Moreover, only one adjusting means in this embodiment could be constructed to achieve the object of the invention. For, example, the carriage-L  11  and the carriage-R  13  could be pivotably connected by the adjusting means  14   a  (or  14   b ), and the torsion of the torsion spring  142   a  (or  142   b ) provides a supporting force upwardly to the carriage-L  11  and the carriage-R  13 .  
      Second Embodiment  
       FIG. 3A  schematically illustrates a disassembled view of the carrying apparatus and the optical scanning module according to the second embodiment of the invention. Components common to both  FIG. 2A  and  FIG. 3A  retain the same numeric designation. The carrying apparatus  10  of the second embodiment is substantially identical to that of the first embodiment, except the pivoting way between the carriage pieces.  
      In the second embodiment, the carrying apparatus  10  includes the first carriage such as a carriage-left (carriage-L)  11 , the second carriage such as a carriage base  12 , and the third carriage such as a carriage-right (carriage-R)  13 . By mounting the groove  122  (formed on the bottom surface of the carriage base  12  and having a half-circular cross section) on the guiding shaft (not shown in  FIG. 3A ), the carrying apparatus  10  is capable of being moved backward and forward along the scanning direction. The torsion spring is also used as the carriage control means. The carriage-L  11  and the carriage-R  13  are rotatably connected to the ends of the carriage base  12  by the adjusting means  16   b  and  16   a.    
      The adjusting means  16   a  includes a torsion spring  162   a , a pivoting shaft  164   a , a coupling portion  166   a  and a fixing pin  168   a . The adjusting means  16   b  includes a torsion spring  162   b , a pivoting shaft  164   b , a coupling portion  166   b  and a fixing pin  168   b  alike. The fixing pins  168   a  and  168   b  are disposed on the bottom surface of the carriage base  12 .  FIG. 3B  is an enlarged bottom view of an adjusting means of the assembled carrying apparatus of  FIG. 3A . Take the adjusting means  16   a  for illustration, the pivoting shaft  164   a  is rotatably engaged with the coupling portion  166   a , and the torsion spring  162   a  is mounted on the fixing pin  168   a . After assembling, two ends of the torsion spring  162   a  touch the carriage base  12  and carriage-R  13  (i.e. the carriage base  12  and carriage-R  13  are subjected to the torsional force of the torsion spring  162   a ), so that a relative rotation between the carriage-R  13  and the carriage base  12  can be generated. The torsion spring  162   b  functions in the same manner as the torsion spring  162   a , so as to make a relative rotation between the carriage-L  11  and the carriage base  12 .  
      Referring again to  FIG. 3A , the ribs  220   a  and  220   b  formed on the housing  22  of the optical scanning module  20  can be relatively inserted into the notches  120   a  and  120   b  configured on the carriage base  12 , for preventing the optical scanning module  20  from sliding. It is, of course, understood that the position and number of the rib-notch sets could be varied without interfering the movement of the carrying apparatus  10 . Additionally, only one adjusting means could be constructed in this embodiment (for example, an adjusting means pivotably connects the carriage-L  11  and the carriage-R  13 ) to achieve the object of the invention.  
      According to the descriptions above, the torsion springs  142   a ,  142   b ,  162   a  and  162   b  are used as the carriage control means; the torsion thereof provides the upward supporting force to the carriage-L  11  and the carriage-R  13 .  
      Third Embodiment  
       FIG. 4  schematically illustrates a disassembled view of the carrying apparatus and the optical scanning module according to the third embodiment of the invention. In the third embodiment, the carrying apparatus  10  includes the first carriage such as a carriage-left (carriage-L)  41 , and the second carriage such as a carriage-right (carriage-R)  43 . The plate spring is used as the carriage control means. After assembling, the carriage-L  41  and the carriage-R  43  are rotatably mounted on the guiding shaft  45 , and the plate spring  46  is disposed beneath the carriage-L  41 , the guiding shaft  45  and the carriage-R  43 . Also, there are two securing components  47   b  and  47   a  respectively disposed on the bottom surface of the carriage-L  41  and the carriage-R  43  for holding two ends of the spring plate  46 . Therefore, the carriage-L  41  and carriage-R  43  are subjected to the elastic force of the plate spring  46 , so as to allow the pivoting of the carriage-L  41  and carriage-R  43  on the guiding shaft  45 . When the optical scanning module  20  is loaded onto the carrying apparatus, the carriage-L  41  and the carriage-R  43  rotatably assembled on the guiding shaft  45  will be forced to moved upward due to the elastic force of the plate spring  46 , thereby lifting the optical scanning module  20  up and against the transparent platen (not shown in  FIG. 4 ).  
      Moreover, for maintaining the position of the optical scanning module  20  on the carrying apparatus, the holding means  48   a  and  48   b  are further disposed on the carriage-R  43  and the carriage-L  41 , respectively. In the illustrated configuration, the holding means  48   a  and  48   b  have a cross section shaped as “L”, and perpendicularly attach to the sides of the optical scanning module  20 . Noted that the holding means  48   a  and  48   b  are able to slightly wiggle on the carriages. The holding springs  481   a  and  481   b , fixed to the barrier plates  483   a  and  483   b  by each end, are connected to the holding means  48   a  and  48   b , respectively. When the carriage-L  41  and the carriage-R  43  are pivoted on the guiding shaft  45 , the angle between the holding means  48   a / 48   b  and optical scanning module  20  changes; meanwhile, the holding springs  481   a  and  481   b  function as the buffers. The elastic force of the holding springs  481   a  and  481   b  makes the holding means  48   a  and  48   b  clutch the optical scanning module  20  under any condition; for example, an angle occurs between the holding means  48   a / 48   b  and optical scanning module  20 . Also, the elastic recovery force of the holding springs  481   a  and  481   b  provide the tendency of the holding means  48   a  and  48   b  for going back to the original positions (i.e. perpendicularly touching the sides of the optical scanning module  20 ).  
      Accordingly, the plate spring  46  is used as the carriage control means in the third embodiment, and the elastic force of the plate spring  46  provides an upward supporting force for pivoting the carriage-L  41  and the carriage-R  43  on the guiding shaft  45 .  
      Fourth Embodiment  
       FIG. 5  schematically illustrates a disassembled view of the carrying apparatus and the optical scanning module according to the fourth embodiment of the invention. Components common to both  FIG. 4  and  FIG. 5  retain the same numeric designation. The carrying apparatus of the fourth embodiment is substantially identical to that of the third embodiment except the component for providing an upward force to the carriages is replaced. In the fourth embodiment, the idle pulley apparatus  56   a  and  56   b , respectively disposed under the carriage-R  43  and carriage-L  41 , are used as the carriage control means.  
      In the illustrated configuration, the idle pulley apparatus  56   a  comprises an idle pulley  561   a  for being able to rolling in the scanner (ex: rolling on the bottom housing of scanner), an idle pulley housing  563   a  coupled to the idle pulley  561   a , and an idle pulley spring  565   a  connected to carriage-R  43  and the idle pulley housing  563   a . The idle pulley apparatus  56   b , having the components identical to that of the idle pulley apparatus  56   a , comprises an idle pulley  561   b , an idle pulley housing  563   b  and an idle pulley spring  565   b.    
      During a scanning operation, the carrying apparatus with the scanning module  20  is driven to move along the guiding shaft  45 , and the idle pulleys  561   a  and  561   b  are simultaneously rolling in the scanner. Meanwhile, the carriage-R  43  and carriage-L  41  are subjected to the elastic force of the idle pulley springs  565   a  and  565   b , so that the optical scanning module  20  is raised up and against the transparent platen by the carriage-R  43  and carriage-L  41 .  
      Accordingly, the idle pulley apparatus  56   a  and  56   b  are used as the carriage control means in the fourth embodiment, and the elastic force of the idle pulley springs  565   a  and  565   b  provide the upward supporting force for lifting the carriage-L  41  and the carriage-R  43  up.  
      Although the carrying apparatus illustrated in the third and fourth embodiments comprises two carriage pieces (i.e. the carriage-L and the carriage-R), it is, of course, understood that the carriage-L and the carriage-R could be pivotably connected to a carriage base as illustrated in the first and second embodiments.  
      While the invention has been described by way of examples and in terms of the 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.