Abstract:
A coating device includes a chamber, an evaporative source, a coating holder, and a supporting structure. The evaporative source is positioned at the bottom of the chamber. The coating holder is positioned at the top of the chamber and includes concentric annular parts with different diameters, and drive devices connected to the annular parts correspondingly. The drive devices are configured to move the annular parts along axial directions of the annular parts. Each annular part includes a bottom board defining receiving holes for receiving lenses. The supporting structure is positioned at the top of the chamber and supports the drive devices.

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to coating technologies and, particularly, to a coating holder and a coating device using the coating holder. 
     2. Description of Related Art 
     Generally, in a coating process for workpieces (e.g., lenses), a spherical coating holder is used to hold several workpieces. However, although the workpieces are positioned on a spherical surface of the coating holder it is difficult and complicated to ensure that all surfaces to be coated are equidistant from an evaporative source. Often, correction plates must be utilized in an attempt to achieve uniform coating on all surfaces, which requires a lot of time and is not highly accurate since the process is manually executed. 
     What is needed, therefore, is a coating holder and a coating device having the same to overcome the above-described problem. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Many aspects of the embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the embodiments. 
         FIG. 1  is a schematic view of a coating device according to an exemplary embodiment. 
         FIG. 2  is a cut-away, isometric view of the coating device of  FIG. 1 . 
         FIG. 3  is a sectional view of the coating device of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure will now be described in detail below, with reference to the accompanying drawings. 
     Referring to  FIGS. 1-2 , a coating device  100 , according to an exemplary embodiment is shown. The coating device  100  includes a chamber  10 , a holder  20 , an evaporative source  30 , and a supporting structure  40 . 
     In the present embodiment, the coating device  100  is a vacuum coating device. The chamber  10  includes a top portion  11 , a sidewall  12 , and a base portion  13  opposite to the top portion  11 . The sidewall  12  is connected between the top portion  11  and the base portion  13 . The holder  20  is positioned at the top portion  11 . The evaporative source  30  is received in the chamber  10 , and fixed at the base portion  13 . The sidewall  12  defines six pairs of through holes  121 ,  122 ,  123  on a same plane and aligned such that lines connecting the holes in each pair of holes  121 ,  122 ,  123  are parallel. 
     The holder  20  is used for holding lenses. In the present embodiment, the holder  20  includes a first annular part  21 , a second annular part  22 , a third annular part  23 , a first drive device  24 , a second drive device  25 , and a third drive device  26 . The number of the annular parts and the drive devices can be varied according to actual needs. 
     In the present embodiment, the first annular part  21 , the second annular part  22 , and the third annular part  23  are all barrel-shaped and coaxial with each other. In other embodiments, the shape of the first annular part  21 , the second annular part  22 , and the third annular part  23  can be polyhedron. 
     The first annular part  21  includes a first bottom board  210 , a first annular wall  211 , and two first lugs  212 . The first bottom board  210  is disk-shaped. The first annular part  21  defines a number of receiving holes  20   a  for receiving lenses to be coated (not shown). The first annular wall  211  surrounds the first bottom board  210 . The two first lugs  212  are fixed on the first annular wall  211  at opposite sides thereof. 
     The configuration of the second annular part  22  is similar to the first annular part  21  and includes a second bottom board  220 , a second annular wall  221 , and two second lugs  222 . In the present embodiment, the inside diameter of the second annular part  22  is equal to or greater than the outside diameter of the first annular part  21 . The second annular part  22  is sleeved over the first annular wall  211  of the first annular part  21 . 
     The configuration of the third annular part  23  is similar to the second annular part  22  and includes a third bottom board  230 , a third annular wall  231 , and two third lugs  232 . In the present embodiment, the inside diameter of the third annular part  23  is equal to or greater than the outside diameter of the second annular part  22 . The third annular part  23  is sleeved over the second annular wall  221  of the second annular part  22 . In the present embodiment, the first lugs  212 , the second lugs  222 , and the third lugs  232  are collinear, when the first annular part  21 , the second annular part  22 , and the third annular part  23  are at the same height. 
     In the present embodiment, the first drive device  24  includes two first motors  240 , two first shafts  241 , and two first strips  242 . Each first shaft  241  is rotatably connected to the corresponding first motor  240 . The first motors  240  are fixed on the supporting structure  40 . The supporting structure  40  includes a beam  41  and two arms  42  connected to two opposite ends of the beam  41 . The two arms  42  are joined to the outside surface of the sidewall  12 . The connection point between the arms  42  and the chamber  20  is lower than the through hole  120 . The two first motors  240  are fixed on the beam  41 , and face the pair of through holes  121  respectively. The two first motors  240  can operate in synchronous rotation. In other embodiments, the first motors  240  can be received in the chamber  10 . The first drive device  24  may, in other embodiments, include only one first motor  240  connected to both of the two first shafts  241 , and the two first shafts  241  are configured to be able to rotate synchronously under control of a gear system or a chain system. 
     The first shafts  241  respectively extend through the two pairs of through holes  121 . One end of each first strip  242  is fixed on the corresponding first lug  212 , the other end of each first strip  242  is wound on the corresponding first shaft  241 . The first strips  242  can be made of high temperature resistant material with belt, chain, or flexible tape like structures. In the present embodiment, the first strips  242  have belt-like structures. In other embodiments, each first shaft  241  may be sleeved by a barrel to increase its diameter within the chamber  10  so that fewer turns are required to wind the first strip  242 . The first drive device  24  can be a hydraulic device or a pressure device and the first annular part  21  can be driven to move by the first drive device  24  through a piston rod. 
     The second drive device  25  includes two second motors  250 , two second shafts  251 , and two second strips  252 . The configuration of the second drive device  25  is the same as the first drive device  24 , except the two second motors  250  face the pair of through holes  122  respectively, and one end of the second strip  252  is fixed on the corresponding second lug  222 . 
     The configuration of the third drive device  26  is the same as the first and the second drive devices  24 , 25  and includes two third motors  260 , two third shafts  261 , and two third strips  262 . The two third motor  260  face the pair of through holes  123  respectively, and one end of the third strip  262  is fixed on the corresponding third lug  232 . In the present embodiment, the first lugs  212 , the second lugs  222 , and the third lugs  232  are arranged at a same diameter, when the unwinding length of the first strip  242 , the second strip  252 , and the third strip  262  are the same. 
     Referring to  FIG. 3 , in the pre-coating process, the height of the first annular part  21 , the second annular part  22 , and the third annular part  23  can be adjusted to ensure the thickness of the film on the lenses positioned in different annular parts are uniform. It is assumed that the thickness of the film on the lenses received in the second annular part  22  will equal an acceptable level without need for adjustment, and the thickness of the film on the lenses received in the first annular part  21  and the third annular part  23  would not meet the acceptable level without adjustment. In this case to make all the lenses having the same thickness film, the first annular part  21  is raised to be a little farther from the source  30  than the second annular part  22 . The third annular part  23  is lowered relative to the second annular part. In the present embodiment, the two first motors  240  synchronously rotate the two first shafts  241  to wind the two first strips  242 . The first annular holder  21  is lifted to increase the distance between the evaporative source  30  and the first annular part  21 . The two third motors  260  synchronously rotate the two third shafts  261  to wind the two third strips  262 . The third annular holder  23  falls to decrease the distance between the evaporative source  30  and the third annular part  23 . 
     While certain embodiments have been described and exemplified above, various other embodiments will be apparent to those skilled in the art from the foregoing disclosure. The present disclosure is not limited to the particular embodiments described and exemplified, and the embodiments are capable of considerable variation and modification without departure from the scope of the appended claims.