Patent Publication Number: US-2013241879-A1

Title: Optical touch module

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a touch module, and in particular to an optical touch module having a simple structure and reduced thickness. 
     2. The Related Arts 
     The technologies of touch panel are various, and their applications range increasingly wider because of improving process and quality. In particular, the development of the optical touch technology brings the touch technology into a new field. Compare to other technologies, types of the optical touch technology are much advantaged of accuracy, high penetration rates, low damage rates, low production cost and being supportive to multiple touch control gestures and so on. 
     The optical touch technology is in use of the principle of light receiving and interrupting. When objects interrupt light, through the coordination of sensors and the reflective elements judging axis, the precise touch positions can be read. However, the traditional optical touch modules are installed on a touch glass, but the touch glass, a liquid crystal display (LCD) and base are spaced form each other. Therefore, a gap between a traditional optical touch screen and a base is huge which increases thickness in assembly, and causes the assembly process to be difficult, and a high manufacturing cost. Besides, a thick configuration does not meet the need of thin and light design in the market. In addition, the touch glass disposed upon LCD result in not only inconvenience with repair but also damage to sensors and reflective elements. 
     SUMMARY OF THE INVENTION 
     An objective of the present invention is to provide an optical touch module having advantages of simple structure, thin and easy to use. 
     To achieve the above objective, an optical touch module of the present invention comprises a frame comprising of a plurality of side walls and an operating space formed by the plurality of side walls. A display module is disposed inside the frame, the display module comprise a base and a touch panel being disposed on the base, a first interval and a second interval being formed opposite to each other and between the base and the side walls of the frame, the touch panel being located adjacent to the operating space. At least one light sensing device comprises a fixed part and a detection part, and the light sensing device is located inside the first interval. At least one reflective element is disposed on the second interval and comprises a reflective surface defined in a same horizontal plane as the detection part and oriented to the detection part. 
     As described above, the optical touch module of the present invention has advantages of significantly reducing whole thickness for structure and saving manufacturing cost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic cross-sectional view of the first embodiment of the present invention; 
         FIG. 2  is a schematic cross-sectional view of the other embodiment of the present invention; and 
         FIG. 3  is a schematic cross-sectional view of the other embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
     With reference to  FIG. 1 , the first embodiment of the present invention is shown in a schematic cross-sectional view. An optical touch module  1  of the present invention is used for image display and is operated or controlled by single-point or multiple-point touch control. The optical touch module  1  comprises a frame  2 , a display module  3 , two light sensing devices  4 , and a plurality of reflective elements  5 . The frame  2  comprises of a plurality of side walls  23 , and a rectangular frame is formed by the plurality of side walls  23  while the shape of the frame is not limited. The space form by the plurality of side walls  23  defines an operating space  20  therein. Frame edges  231  protrude into the operating space  20  from the plurality of side walls  23 . The plurality of side walls  23  comprises an inner wall face  232 . In other word, the plurality of side walls  23  and the corresponding frame edge  231  form a profile of an inverted “L” together in a cross sectional view thereof. 
     The display device  3  is assembled inside the frame  2 , and comprises a base  31 , a touch panel  32  that is located at the base  31 . A first interval  21  and a second interval  22  being formed opposite to each other and between the base  31  and the side walls  23  of the frame  32 . In other words, the frame edges  231  are located above the first intervals  21  and second intervals  22 , and have inner wall faces, respectively, and the inner wall faces are parallel to the touch panel  32 . In particular, the touch panel  32  being located adjacent to the operating space  20 , therefore, there is no other components are located above the touch panel  32 . The underside that is one side of the operating space  20  of the touch panel  32  is connected to the base  31  electrically. In this embodiment, the touch panel  32  is a liquid crystal display (LCD). Besides, wherein a positioning plate  22  are provided on peripheral sides  311  of the base  31  adjacent to the touch panel  32  (Referring to  FIG. 1 ). 
     Further referring to  FIG. 1 , the optical touch module  1  of the present invention comprises two light sensing devices  4  respectively located inside the first interval  21 . The frame edge  24  is located above the light sensing devices  4  to function as a cover and protection of the light sensing devices  4 . Each of the light sensing devices  4  comprises a fixed part  41 , a detection part  42  and it connected to a touch integrated circuit (IC) (No Figure). In this embodiment, the detection part  42  is a camera device that is in the corner of the display device  3 . The fixed part  41  is settled on the positioning plate  33  of the base  31  and spaced apart from frame  2 . The detection part  42  is facing toward the operating space  20 . 
     Each of the plurality of reflective elements  5  comprises a frame edge that is located inner the first interval  21  and the second interval  22  and fixed on the positioning plate  33  of the second interval  22 . The reflective surface  51  is roughly located at the same horizontal plane as the detection part  42 , and oriented to the detection part  42 . 
     In this embodiment, the plurality of reflective elements  6  can be reflective strips distributed over the part of margin of the base  31 , the detection part  42  detects and senses the light reflected by the reflection strips of the plurality of reflective elements  5 . In addition, the generation of light source  43  of the present invention can be a light emitting diode (LED) element (Referring to  FIG. 1 ) or other light emitting element, the light emitted passes through the operating space  20  to the reflective elements  5 . The light emitting element  43  is disposed on or adjacent to the light sensing devices  4 . 
     With reference to  FIG. 2  showing the other embodiment of the present invention, the light sensing devices  4  and the reflective elements  5  is located above the frame  2  of the first interval  21  and the second interval  22  separately and keeps space from the display device  3 . The fixed part  41  of the light sensing devices  4  and the reflective elements  5  adjacent to the inner surface  231  of frame edge  23 , and the frame edge of reflective elements  5  aims at the detection part  42 . 
     With referring to  FIG. 3  showing the other embodiment of the present invention, the configuration of light sensing device  4  and the reflective elements  5  can also be installed the way that the light sensing device  4  is located on the base  31  and spaced apart from frame  2 , the reflective elements  5  is located on frame edge  231  of the frame  2  and spaced apart from the base  31 , and the frame edge of reflective elements  5  oriented to the detection part  42 . 
     In use of the present invention, through the principle of light received and interrupted, when there are objects (such as fingers) interrupting light of the operating space  20  and touching the touch panel  32 , the light sensing device  4  detects shading change and operates calculations by touch integrated circuit (IC) to determines the touched location precisely. 
     Accordingly, the optical touch module  1  of the present invention don&#39;t need install a layer of traditional touch glass, we can touching the LED touch panel directly. It can reduce the overall thickness significantly and reduce manufacturing costs. In addition, the light sensing device and reflective element of the present invention are not located above touch panel, but located above base or frame, therefore, not only panel without damages to the display device  4 , but also convenient to whole maintenance process. 
     The above detailed descriptions are only illustrative for one feasible embodiment of the present invention. However, the illustrative embodiment is not intended to limit the scope of claims of the present invention. It is apparent to those skilled in the art that a variety of modifications and changes may be made without departing from the scope of claims of the present invention which is intended to be defined by the appended claims.