Abstract:
A structure of a scanner includes a housing having a top provided with a glass window, a carriage mounted inside housing, the carriage including a a casing having a plurality of openings, a light source arranged within the casing for illuminating an object placed face down against the glass window above the carriage, and a plurality of mirrors fitted in the openings, whereby the scanner is compact in size and easy to assemble.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention is related to an improved structure of a scanner and in particular one which is compact in size and easy to assemble. 
     2. Description of the Prior Art 
     It has been long desired to have a scanner which is compact in size and easy to assemble, but none of the scanners on the market are satisfactory in these areas. Referring to FIG. 1, the conventional scanner  1  generally includes a glass window  11  and a carriage  12 . The carriage  12  includes a casing  121 , a light source  122 , a first mirror  123 , a second mirror  124 , a first mirror  123 , a second mirror  124 , a third mirror  125 , a fourth mirror  126 , a lens assembly  127 , and a charge coupled device (CCD)  128 . The casing  121  is formed with an opening  1211  and a piece of paper  13  is placed face down against the glass window  11  above the carriage  12 . 
     As shown, the casing  121  is generally rectangular in shape, in which are arranged the light source  122 , the mirrors  123 - 126 , the lens assembly  127  and the charge coupled device  128 . As the carriage  12  is moved beneath the page  13 , the light source  122  illuminates the paper  13  and the carriage  12  captures light bounced off individual areas of the paper  13 . Thereafter, the light from the paper  13  is reflected through the mirrors  123 - 126  to the lens assembly  127  which focuses the light onto the charge coupled device (CCD)  128  that translate the amount of light into an electrical current. 
     However, as shown in FIG. 1, the casing  121  is a closed rectangular member with only one opening  1211  at the top and so all component parts must be correctly arranged inside the casing  121  before it is closed. As a consequence, when required to adjust the component parts, it is necessary to open the casing  121  thereby causing much inconvenience in maintainence. In addition, since the mirrors  123 - 126  are mounted inside the casing  121 , there must be fastening means for fixing the mirrors in place thus increasing the manufacturing cost. 
     Therefore, it is an object of the present invention to provide an improved structure of a scanner which can obviate and mitigate the above-mentioned drawbacks. 
     SUMMARY OF THE INVENTION 
     This invention is related to an improvement in the structure of a scanner. 
     It is the primary object of the present invention to provide an improved structure of a scanner which is compact in size and easy to assemble. 
     According to the present invention, a structure of a scanner includes a housing having a top provided with a glass window, a carriage mounted inside housing, the carriage including a casing having a plurality of openings, a light source arranged within the casing for illuminating an object placed face down against the glass window above the carriage, and a plurality of mirrors fitted in the openings. 
     The foregoing objects and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. 
     Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view of a prior art scanner; 
     FIG. 2 is a sectional view of the carriage according to the present invention; 
     FIG. 3 is a top perspective view of the carriage according to the present invention; 
     FIG. 4 is a left side perspective view of the carriage according to the present invention; and 
     FIG. 5 is a perspective view illustrating how to mount the first mirror in the casing. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings. Specific language will be used to describe same. It will, nevertheless, be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated herein being contemplated as would normally occur to one skilled in the art to which the invention relates. 
     With reference to the drawings and in particular to FIG. 2 thereof, the scanner  2  according to the present invention comprises a housing having a glass window  21  at the top and a carriage  22  inside the housing. The carriage  22  generally includes a casing  221  having an opening  2210 , a first hole  2211 , a second hole  2212 , a third hole  2213 , a fourth hole  2214 , a light source  222 , a first mirror  223 , a second mirror  224  having a first position A and a second position B, a third mirror  225 , a fourth mirror  226 , a lens  227 , and a charge coupled device (CCD)  228 . The light source  222  is provided with a convergent means such as a lampshade (shown but not numbered). A piece of paper  23  is placed face down against the glass window  21  above the carriage  22 . 
     As shown in FIG. 2, the carriage  22  is driven by a motor (not shown). As the carriage  22  is moved beneath the page  23 , the light source  222  illuminates the paper  23  and the carriage  22  captures light bounced off individual areas of the paper  23 . 
     Then, the light from the paper  23  is reflected through the first mirror  223  to the first position A of the second mirror  224 . 
     Thereafter, the light from the second mirror  224  is reflected to the third mirror  225 . 
     The light from the third mirror  225  is reflected to the second position B of the second mirror  224 . 
     Then, the light from the second mirror  224  is reflected to the fourth mirror  226 . 
     Finally, the light from the fourth mirror  226  is reflected to the lens  227  which focuses the light onto the charge coupled device (CCD)  228  that translate the amount of light into an electrical current. The more light that is reflected, the higher the voltage of the current will be. 
     FIGS. 3,  4  and  5  illustrate different perspective views of the present invention. FIG. 3 is a perspective view of the present invention, looking from the top of FIG.  2 . FIG. 4 is a top perspective view of the present invention, looking from the left side of FIG.  2 . FIG. 5 is a perspective view of the present invention, illustrating how to mount the first mirror  223  in the casing  221 . 
     Another feature of the present invention resides in that the mirrors  223 - 226  are respectively mounted on the openings  2211 - 2214  of the casing  221 . In order to make clear the arrangement of the mirrors  223 - 226 , the engaging structure  229  will now be described hereinafter with FIG.  5 . FIG. 5 illustrates the carriage  22 , the casing  221 , the first hole  2211 , the fourth hole  2214 , and the engaging structure  229  with two recesses  2291  and two hooks  2292 . 
     The first hole  2211  and the fourth hole  2214  are used for mounting the first mirror  223  and the fourth mirror  226 . The casing  221  is formed with a second opening  2212  (see FIG. 4) for mounting the second mirror  224  and a third opening  2213  for mounting the third mirror  225 . The opening  2211 - 2214  are each provided with an engaging structure  229  so that the mirrors  223 - 226  are movably mounted in the openings  2211 - 2214  thereby enabling the mirrors  223 - 226  to be fixed in place in one hand and facilitating the disassembly of the mirrors  223 - 226  in the other hand. 
     Referring to FIG. 5, each engaging structure  229  is provided with a recess  2291  and a hook  2292 . When the mirror  223  can be inserted between the hooks  2291  and the casing  221  into the two recesses  2291 , the hooks  2291  will bear against the mirror  223  thereby keeping the mirror  223  in the opening  221 . 
     It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. 
     While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. 
     Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.