Abstract:
A projection device of the invention includes a housing, a light engine disposed in the housing, a lens disposed on a lateral side of the housing, and a light direction regulating mechanism disposed on the lateral side and in front of the lens. The light direction regulating mechanism is able to determine propagation of the light in a selected direction after the light passes through the lens.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to a projection device, and more particularly to a projection device capable of changing the direction of light projection. 
         [0003]    2. Description of the Related Art 
         [0004]    Referring to  FIGS. 1 and 2 , a conventional projection device  10  includes a first housing  12  and a second housing  14 . The first housing  12  is pivoted to the second housing  14  by a hinge  13 . A light engine (not shown) and a lens  15  are disposed in the first housing  12 . A circuit board and a power supply (not shown) are disposed in the second housing  14 . In operation, the direction of light projection can be changed only by rotating the first housing  12 . In the described structure, however, the light engine is disposed in the first housing  12  and the power supply and the circuit board are disposed in the second housing  14 . Therefore, a flexible printed circuit board extending between the first housing  12  and the second housing  14  is necessary. Such structure is complicated. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    To address the shortcomings discussed, the invention provides a projection device with simple structure and high reliability, in which a mirror is used for changing the direction of light projection. The projection device in accordance with an exemplary embodiment of the invention includes a housing, a light engine disposed in the housing to emit light, a lens disposed on a lateral side of the housing, for the light to pass therethrough, and a light direction regulating mechanism disposed on the lateral side and in front of the lens, to determine propagation of the light in a selected direction after the light passes through the lens. 
         [0006]    In another exemplary embodiment, the light direction regulating mechanism includes a movable mirror, and the light passing through the lens is reflected by the mirror when the mirror is moved to be in front of the lens. 
         [0007]    In yet another exemplary embodiment, an angle is formed between a normal line of the mirror and the selected direction. 
         [0008]    In another exemplary embodiment, the angle is substantially 45°. 
         [0009]    In yet another exemplary embodiment, the light direction regulating mechanism further comprises a cover body comprising a first opening, and the mirror is disposed in the cover body. 
         [0010]    In another exemplary embodiment, the cover body comprises a partition wall dividing the interior space of the cover body into a first space and a second space. 
         [0011]    In yet another exemplary embodiment, the first opening corresponds to the first space, and the mirror is disposed in the second space. 
         [0012]    In another exemplary embodiment, the cover body further comprises a front wall on which the first opening is formed. 
         [0013]    In yet another exemplary embodiment, the cover body is disposed on the lateral side and slidable between a first position and a second position, the light passing through the lens exits from the first opening when the cover body is in the first position, and the mirror is disposed in front of the lens to reflect the light passing through the lens when the cover body is in the second position. 
         [0014]    In another exemplary embodiment, the light direction regulating mechanism further comprises a front cover disposed on the cover body to selectively cover or expose the first opening, and the light passing through the lens exits from the first opening when the first opening is exposed. 
         [0015]    In yet another exemplary embodiment, the cover body is disposed on the lateral side of the housing and rotatable between a third position and a fourth position, the light passing through the lens exits from the first opening when the cover body is rotated to the third position, and the mirror is disposed in front of the lens to reflect the light passing through the lens when the cover body is rotated to the fourth position. 
         [0016]    In another exemplary embodiment, the cover body is rotatably disposed on the housing through a shaft. 
         [0017]    In yet another exemplary embodiment, the light direction regulating mechanism further comprises a front cover disposed on the cover body to selectively cover or expose the first opening, and the light passing through the lens exits from the first opening when the first opening is exposed. 
         [0018]    In another exemplary embodiment, the light direction regulating mechanism further comprises a front cover disposed on the cover body to selectively cover or expose the first opening, and the light passing through the lens exits from the first opening when the first opening is exposed. 
         [0019]    In yet another exemplary embodiment, the mirror is slidably disposed in the cover body, and the light passing through the lens is reflected by the mirror when the mirror slides to be in front of the lens. 
         [0020]    In another exemplary embodiment, the cover body further comprises a front wall on which the first opening is formed, a lateral wall and a second opening formed on the lateral wall, when the mirror slides to be in front of the lens, the light reflected by the mirror passes through the second opening. 
         [0021]    In yet another exemplary embodiment, the lateral wall is adjacent to the front wall. 
         [0022]    In another exemplary embodiment, the cover body further comprises a first front cover configured to cover the first opening and a second front cover configured to cover the second opening. 
         [0023]    In yet another exemplary embodiment, the light direction regulating mechanism further comprises a cover body detachably mounted on the lateral side of the housing and in front of the lens, the mirror is disposed in the cover body, and the mirror is disposed in front of the lens to reflect the light passing through the lens when the cover body is mounted on the lateral side of the housing. 
         [0024]    In another exemplary embodiment, the cover body is a hollow cuboid. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]    The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
           [0026]      FIGS. 1 and 2  depict a conventional projection device; 
           [0027]      FIG. 3  is a perspective view of an embodiment of a projection device of the invention; 
           [0028]      FIGS. 4 and 5  depict the projection device of  FIG. 3  in use; 
           [0029]      FIGS. 6A and 6B  are perspective views of another embodiment of a projection device of the invention; 
           [0030]      FIGS. 7A and 7B  are perspective views of another embodiment of a projection device of the invention; and 
           [0031]      FIG. 8  is a perspective view of another embodiment of a projection device of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0032]    The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims. 
         [0033]    Referring to  FIGS. 3 and 4 , a projection device  100  includes a housing  20 . A light engine (not shown) is disposed in the housing  20 . A lens  30  disposed on a lateral side  22  of the housing  20  is connected to the light engine. A light direction regulating mechanism  40  is disposed on a lateral side  22  of a housing  20 . The light direction regulating mechanism  40  includes a cover body  42 , a mirror  44  and a front cover  46 . The cover body  42  is a hollow cuboid and slidably disposed on the lateral side  22  of the housing  20  to hide the lens  30 . The cover body  42  has a partition wall  421 (shown in  FIG. 5 ) which divides the interior space of the cover body  42  into a first space  422  and a second space  424 . The cover body  42  further has a front wall  425 . An opening  426  corresponding to the first space  422  is formed on the front wall  425 . The front cover  46  is slidably disposed on the front wall  425  and capable of covering the opening  426 . The mirror  44  is disposed on the second space  424  and has a normal line intersecting an optical axis of the lens  30  to substantially form an angle of 45°. 
         [0034]    Referring to  FIGS. 4 and 5 , the cover body  42  is disposed on the lateral side  22  of the housing  20  slidable between a first position and a second position. When the cover body  42  slides to the first position, as shown in  FIG. 4 , the lens  30  is directed to the first space  422 . Thus, light can pass through the lens  30  and the opening  426  to be projected to an object, such as a screen, if the front cover  46  slides to expose the opening  426 . When the cover body  42  slides to the second position, as shown in  FIG. 5 , the lens  30  is directed to the second space  424 . Light passing through the lens  30  is reflected by the mirror  44  to travel substantially at an angle of 90° with respect to the optical axis of the lens  30 . Thus, light direction of  FIG. 5  is changed at about 90° as compared with the light direction of  FIG. 4 . In practical applications, the originally forward-projected light is projected to a ceiling or a desk. 
         [0035]      FIGS. 6A and 6B  depict another embodiment of a projection device of the invention. In this embodiment, the cover body  42  has the same structure as the embodiment shown in  FIGS. 3-5 . The cover body  42  is disposed on a lateral side  22  of the housing  20  and rotatable between a third position and a fourth position with respect to a hinge  48 . When the cover body  42  is rotated to the third position, as shown in  FIG. 6A , the lens  30  is directed to the first space  422 . Thus, light can pass through the lens  30  and the opening  426  to be projected on an object, such as a screen, if the front cover  46  slides away to expose the opening  426 . When the cover body  42  is rotated to the fourth position, as shown in  FIG. 6B , the lens  30  is directed to the second space  424 . Light passing through the lens  30  is reflected by the mirror  44  to travel substantially at an angle of 90° with respect to the optical axis of the lens  30 . Therefore, light direction of  FIG. 6B  is changed at about 90° as compared with the light direction of  FIG. 6A . 
         [0036]      FIGS. 7A and 7B  depict another embodiment of a projection device of the invention. In this embodiment, the cover body  42  has a structure different from previous embodiments. The cover body  42  is a hollow cuboid and fixed to the lateral side  22  of the housing  20 . A first opening  428  and a second opening  429  corresponding to the lens  30  are respectively formed on the front wall  425  and a lateral wall  427  of the cover body  42 . The mirror  44  is disposed in the cover body  42 , and has a normal line intersecting an optical axis of the lens  30  to form an angle of 45°. The mirror  44  is disposed in the cover body  42  and movable between a fifth position and a sixth position. When the mirror  44  is in the fifth position, as shown in  FIG. 7A , the lens  30  is directed to the first opening  428 , and light passes through the lens  30  and the first opening  428  to be projected on an object, such as a screen. When the mirror  44  moves to the sixth position (in front of the lens  30 ), as shown in  FIG. 7B , light passes through the lens  30  and is reflected by the mirror  44  to travel in an angle of 90° with respect to the optical axis of the lens  30  to passes through the second opening  429 . Therefore, light direction of  FIG. 7B  is changed at 90° as compared with the light direction of  FIG. 7A . To avoid light leakage, a first front cover and a second front cover are disposed in front of the first opening and the second opening. For the sake of clarity, the first front cover and the second front cover are omitted in  FIGS. 7A and 7B . The mechanism for moving the mirror  44  may be a push rod connected to the mirror  44 , which is manually operated. However, the mechanism for moving the mirror  44  is not limited thereto. 
         [0037]      FIG. 8  depicts another embodiment of a projection device of the invention. In this embodiment, the cover body  42  is detachably mounted on the lateral side  22  of the housing  20 . The mirror  44  is mounted on the cover body  42 . When the cover body  42  is not mounted, light passes through the lens  30  to be projected to an object, such as a screen. When the cover body  42  is mounted in front of the lens  30 , light passes through the lens  30  and is reflected by the mirror  44  to travel approximately at an angle of 90° with respect to the optical axis of the lens  30 . 
         [0038]    The projection device of the invention uses mirror  44  to change light direction. The housing bearing the light engine and the lens does not need to be divided into two parts, which causes a simple structure, high reliability and low cost.