Abstract:
A projector includes a projector body, a lens module with a lens, and a gear module. The lens module and the gear module are arranged in the projector body. The gear module is operable to adjust a height of the lens and keep an angle of the lens, in response to the gear module being rotated.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present invention relates to projectors, and particularly, to a projector which can adjust the height of a lens of the projector conveniently. 
         [0003]    2. Description of Related Art 
         [0004]    Projectors are used very widely in a lot of places, such as offices, homes, etc. Some times, users need to heighten up a height of a lens of a projector to make a height of the projecting image from the lens match a projected screen. However, when the height of the lens is heightened up to a certain angle, the image on the projected screen may be distorted because the angle of the lens is changed correspondingly, which may influence projected images. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is an exploded, isometric view of an exemplary embodiment of a projector including a lens module and a gear module. 
           [0006]      FIG. 2  is an assembled, isometric view of the lens module and the gear module of  FIG. 1 . 
           [0007]      FIG. 3  is an assembled view of the projector of  FIG. 1 . 
           [0008]      FIG. 4  is a cutaway, isometric view of the projector of  FIG. 3 , in a first situation. 
           [0009]      FIG. 5  is a side elevational view of the projector of  FIG. 4 . 
           [0010]      FIG. 6  is similar to  FIG. 4 , but in a second situation. 
           [0011]      FIG. 7  is a side elevational view of the projector of  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    Referring to  FIGS. 1 and 2 , an embodiment of a projector  100  includes a projector body  10 , a lens module  20  including a lens  22  and a gear module  30 . 
         [0013]    The projector body  10  is approximately rectangular-shaped. A front panel  11  of the projector body  10  defines a through hole  12  for receiving the lens  22 . A diameter of the through hole  12  is little greater than a diameter of the lens  22 . Two opposite sidewalls  13  of the projector body  10  each define a pivot hole  14 . A bottom  15  of the projector body  10  defines two through holes  16  and  18  (see  FIG. 5 ), and two screw holes (not shown) at opposite sides of each of the two through holes  16  and  18 . It may be understood that the projector body  10  also includes other function elements, such as a power module, and a control module for example. These other function elements fall within well-known technologies, and are therefore not described here. 
         [0014]    The lens  22  extends from a front wall  21  of the lens module  20 . Two opposite sidewalls  23  of the lens module  20  each include a post  24  corresponding to the pivot holes  14  of the projector body  10 . A rectangular connecting portion  26  vertically extending from a back wall  25  of the lens module  20  forms a supporting construction for the lens module  20 . A bottom of the connecting portion  26  defines a rectangular groove  266  therein. Two pivot holes  264  are defined in two opposite end surfaces of the connecting portion  26 , communicating with the groove  266 . A U-shaped slot  262  is defined in a distal side of the connecting portion  26 , opposite to the back wall  25  and communicating with the groove  266 . 
         [0015]    The gear module  30  includes a blocking element  31 , a rotatable element  32 , a first gear element  34 , and a second gear element  36 . 
         [0016]    The blocking element  31  includes a rectangle board  314  and a post  312  vertically extending from a center of the board  314 . The blocking element  31  defines a screw hole (not labeled), through the post  312  and the board  314 . 
         [0017]    The rotatable element  32  is approximately U-shaped, and includes two parallel arms  321  and a connection portion  322  perpendicularly connected between corresponding ends of the arms  321 . Inner walls of the arms  321  define two slide slots  324 , respectively. A connecting pole  326  is mounted to the connection portion  322 , opposite to the arms  321 . Opposite ends of the board  314  of the blocking element  31  are capable to be slidably engaged in the slide slots  324 , respectively. Two opposite ends of the connecting pole  326  extended out of the connection portion  322 , are capable to be engaged in the pivot holes  264  of the connecting portion  26  of the lens module  20 , respectively. 
         [0018]    The first gear element  34  includes a screw pole  342  having a round cross-section, a gear  344  defining a round mounting hole  3442  in a center, and a mounting rack  346 . The second gear element  36  includes a screw pole  362  having a double-D shaped cross-section, a gear  364  defining a double-D shaped mounting hole  3642 , and a mounting rack  366 . The screw pole  362  further includes a round rotating portion  3624  extending from a first end of the screw pole  362  to be operated to rotate the screw pole  362 , and a nut  3626  to be engaged with a second end of the screw pole  362  opposite to the first end. The mounting rack  346  is similar to the mounting rack  366 , therefore, the follow description only describes the construction of the mounting rack  366 . 
         [0019]    The mounting rack  366  includes a rectangular base  3662 , a connecting piece  3664  with a U-shaped cross-section, and two screws  3667 . Two through holes  3661  are defined in two ends of the base  3662 . A screw hole  3663  is defined in a center of the base  3662 , between the two through holes  3661 . The connecting piece  3664  includes a rectangular portion  3669  defining a U-shaped opening  3666 . Two hems  3668  extend vertically downwardly from two opposite sides of the portion  3669  and then extend out vertically. Two through holes  3665  are defined in the two hems  3668  respectively, corresponding to the two through holes  3661  of the base  3662 . 
         [0020]    Referring to  FIGS. 2 to 5 , in assembly, opposite ends of the board  314  of the blocking element  31  are slidably engaged in the slide slots  324  of the rotatable element  32 , respectively. Opposite ends of the connecting pole  326  of the rotatable element  32  are engaged in the two pivot holes  264  of the connecting portion  26  of the lens module  20 , with the post  312  of the blocking element  31  engaged in the slot  262  of the connecting portion  26  of the lens module  20 . The combined assembly of the lens module  20  and the blocking element  31  are accommodated in the projector body  10 , with the posts  24  of the lens module  20  rotatably engaged in the pivot holes  14  of the projector body  10 , respectively. The lens  22  is inserted into the through hole  12  and exposed outside the projector body  10 . The screw pole  362  of the second gear element  36  is inserted into the through hole  16  of the projector body  10 , screwed into the screw hole  3663  of the base  3662  of the mounting rack  366 , through the opening  3666  of the connecting piece  3664 , inserted into the mounting hole  3642  of the gear  364 , and then screwed into the nut  3626 . The two screws  3667  are extended through the two through holes  3665  of the connecting piece  3664 , the two though holes  3661  of the base  3662 , and then screwed in the two screw holes at opposite sides of the through hole  16  of the projector body  10 . The assembly process of the first gear element  34  is similar to the assembly process of the second gear element  36  mentioned above, so the description of the assembly process of the first gear element  34  will be omitted. A distal end of the screw pole  342  is engaged in the screw hole of the post  312  of the blocking element  31 . The gear  344  and the gear  346  mesh with each other. 
         [0021]    Referring to  FIGS. 4 to 7 , in use, the projector  100  is placed on a table (not shown). When the rotating portion  3624  of the screw pole  362  is rotated, the screw pole  362  will move up and down relative to the projector body  10 , according to the rotating direction of the rotating portion  3624 . Therefore, an angle between the bottom of the projector body  10  and the table can be adjusted by rotating the rotating portion  3624 .  FIG. 5  shows a status in which the angle between the bottom of the projector body  10  and the table is least, almost zero degrees, and  FIG. 7  shows a status in which the angle between the bottom of the projector body  10  and the table is greatest. When the angle between the bottom of the projector body  10  and the table is adjusted, the height of the lens  22  is adjusted indirectly, and the height of the lens  22  is lowest shown in  FIG. 5  while highest shown in  FIG. 7 . 
         [0022]    The gear  364  is also rotated with the rotation of the screw pole  362 , to rotate the gear  344 . The moving directions of the screw pole  342  and the screw pole  362  are reverse. When the screw pole  342  moves up, the connecting portion  26  of the lens module  20  is pushed up by the screw pole  342  to rotate the lens module  20  about the posts  24 , therefore, the lens  22  moves down. Therefore, when the angle between the bottom of the projector body  10  and the table is changed by rotating the rotating portion  3624 , the lens  22  is rotated reversely. If a gear ratio between the gears  344  and  364  is selected suitably, an angle between the lens  22  and the table will not be kept constant or substantially so, which cannot influence projected images. 
         [0023]    It is to be understood, however, that even though numerous characteristics and advantages of the embodiments have been set forth in the foregoing description, together with details of the structure and function of the embodiments, the disclosure is illustrative only, and changes may be made in details, especially in matters of shape, size, and arrangement of parts within the principles of the embodiments to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.