Abstract:
A finely adjustable optical mechanism includes a base, a lens seat mounted on the base, a mirror set mounted on the base. A lens and an image sensor are mounted on the lens seat. A link is provided between the lens seat and the base. It is possible to move the lens seat relative to the base by rotating the link to move the lens seat or the base. Accordingly, the relatively positional relationship between the lens seat and the base can be finely adjusted.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to an adjustable optical mechanism of a scanner, and more particularly, to an optical mechanism wherein the relative position between the lens and the reflection mirror set can be finely adjusted.  
         BACKGROUND OF THE INVENTION  
         [0002]    A conventional optical mechanism generally includes a lens, an image sensor such as CCD and a reflection mirror set composed of several reflection mirrors. The lens and the image sensor are mounted to a lens seat which is connected to a base together with a reflection mirror set.  
           [0003]    It is to be noted that the lens is fixed to the base and the lens seat is fixed to the base by at least two pins or screws fixed on the base. Therefore, no relative movement is happened between the combination of the lens and the image sensor, and the reflection mirror set.  
           [0004]    Because the lens seat and the reflection mirror set are fixed to the base, the focus and the depth of the scanned image may involve errors if the installation is not correct and precise. Although an adjusting method can be done to adjust the position of the lens seat and the reflection mirror set, it is difficult because both of which are fixed and the result is not satisfied and a worse scanning result will be obtained.  
           [0005]    Besides, there is only one allocation for the reflection mirror set and the lens seat on the base, it is impossible to change the position of the lens seat and the focus of the lens to achieve the purpose of changing the focus. Therefore, the molds cannot be used in common and this increases the manufacturing cost.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention provides a finely adjustable optical mechanism which can be adjusted along multiple axes (directions) so as to be assembled precisely and obtain high quality of scanning.  
           [0007]    Another object of the present invention is to provide a finely adjustable optical mechanism wherein the relative position between the lens seat and base can be adjusted so that the focus of the lens can be changed to change the magnifying rate and resolution without changing the base and the optical mechanism. Therefore, the molds can be used in common.  
           [0008]    The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is an exploded view of the present invention.  
         [0010]    [0010]FIG. 2 is a top view of the assembly of the present invention.  
         [0011]    [0011]FIG. 3 shows the assembly of the present invention.  
         [0012]    [0012]FIG. 4 shows one of the movements of the adjustment.  
         [0013]    [0013]FIG. 5 shows another movement of the adjustment.  
         [0014]    [0014]FIG. 6 illustrates the movement of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0015]    [0015]FIG. 1 is an exploded view of the present invention and discloses an optical mechanism which comprises a base  11 , a lens seat  21 , an image sensor  31  and a link  14 .  
         [0016]    The base  11  has a protrusion  12  on a surface thereof and two protruding locking posts  13 . A chamber  14  is defined in an end of the base  11  and a reflection mirror set (not shown) composed of several reflection mirrors is received in the chamber  14 .  
         [0017]    A lens  22  is mounted on an end of the lens seat  21  which includes two lugs  23  on two sides. Each lug  23  has an elongate hole  24  and the lens seat  21  has a recess  25  in an underside of the lens seat  21 .  
         [0018]    The image sensor  31  in this embodiment is a CCD and fixed to a board  32 . The link  41  is formed with a hole  42  at one end and a convex  43  at the other end.  
         [0019]    [0019]FIG. 2 is a top view of the assembly of the present invention and FIG. 3 shows the assembly of the present invention. The board  32  of the image sensor  31  is fixed to the end of the lens seat  21  and located away from and facing the lens  22 . It is to be noted that the board  32  is movable and swingable relative to the lens seat  21 , so that the relative position between the image sensor  31  and the lens  22  can be finely adjusted.  
         [0020]    The lens seat  21  is connected to the base  11  and the two locking posts  13  of the base  21  are located in correspondence to the elongate holes  24  of the lens seat  21 . A proper locking member (not shown) locks the locking posts  13  in the elongate holes  24 .  
         [0021]    The link  41  has the hole  42  at one end thereof to be mounted to the protrusion  12  and the link  41  is rotatable relative to the protrusion  12 . The convex  43  of the link  41  is received in the recess  25  at the underside of the lens seat  21 . The lens seat  21  can be swung by the engagement of the recess  25  and the convex  43 .  
         [0022]    In the practical manufacturing process, the lens seat  21  can be made of solid material so as to ensure that the image sensor  31  on the board  32  is perpendicular to the axis passing through the lens  22 .  
         [0023]    [0023]FIG. 4 shows one of the movements of the adjustment. The base  11  is fixed and the link  41  swings an angle from the horizontal position. By this way, the lens seat  21  moves downward and swings an angle. When the lens seat  21  swings, the elongate hole  24  is still maintained at the corresponding position.  
         [0024]    [0024]FIG. 5 shows another movement of the adjustment. After the lens seat  21  is swung, the lens seat  21  may rotate an angle due to the engagement of the convex  43  and the recess  25  so that the optical data of the image obtained from scanning may pass through the lens  22  and is received by the image sensor  31 .  
         [0025]    After the lens seat  21  is adjusted, the locking members are used to lock the locking posts  13  in the elongate holes  24  so that the lens seat  21  is fixed and not able to move and swing.  
         [0026]    [0026]FIG. 6 illustrates the movement of the present invention. The blocks in the diagram represent the lens seats  21  and after the lens seat  21  and the link  41  swing and rotate, the positions in the X axis and the Y axis are both moved.  
         [0027]    In other words, by the movements in the X axis and the Y axis, the lens seat  21  and the base  11  have relative movements in two directions. When further considering the self-rotation of the lens seat  21 , the movement of the lens seat  21  can be adjusted in three directions. Correspondingly, the relative position between the lens  22  and the reflection mirror set (not shown) may be finely adjusted.  
         [0028]    Thanks to the cooperation of the lens seat  21  and the link  41 , the lens seat  21  on the base  11  can be adjusted in multiple directions. If the installation has any error, the relative position of the lens seat  21  and the base  11  may be finely adjusted. Accordingly, the scanned image information can pass through the reflection mirror set (not shown) on the base  11 , the lens  22  on the lens seat  21 , and can be received by the image sensor  31  to generate the best quality of the image.  
         [0029]    The relative position of the lens seat  21  and the base  11  may be adjusted, the distance between the reflection mirror set (not shown) on the base  11  and the lens  22  on the lens seat  21  may be also adjusted. In the theory of forming of image, the distance between the reflection mirror set and the lens  22  means the change of the object distance. The unchanged distance between the lens  22  and the image sensor  31  represents the image distance is not changed. Accordingly, the manufacturers may only change the lens  22  of the optical mechanism to obtain the magnifying rate of the image and the resolution by the change of the relative positions of the lens  21  and the base  11 . Therefore, the users may have different magnifying rates and resolutions without changing the size of the base  11  and the lens seat  21 .  
         [0030]    While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.