Patent Publication Number: US-2011050646-A1

Title: Optical touch apparatus and optical touch display apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the priority benefit of Taiwan application serial no. 98129124, filed on Aug. 28, 2009. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a touch apparatus and a touch display apparatus, and particularly to an optical touch apparatus and an optical touch display apparatus. 
     2. Description of Related Art 
     As information technique, wireless mobile communication, and information appliances have been rapidly developed, to achieve more convenience, more compact and light volume and more user-friendly designs, various information products have changed from conventional input devices such as key boards or mice to touch panels. A touch panel may be attached to a display device to form a touch panel display device. Touch panels may be categorized into resistance touch panels, capacitance touch panels, optical touch panels, sound wave touch panels, and electromagnetic touch panels, etc, based on differences in the sensing principles. 
     In a resistance touch panel, a voltage drop is generated at a conductive place when two conductive layers originally separated from each other are connected together due to a single-point press. Then, a coordinate where the user presses is determined according to the position of the voltage drop. On the other hand, in a capacitance touch panel, a uniform electric field is formed between an inner conductive layer and an outer conductive layer. When a conductor (e.g. a finger of human) touches the panel, a slight variation of capacitance occurs. Hence, the coordinate of the touch position on the panel is determined according to the position of the variation of capacitance. 
     Furthermore, a manufacturing method relative to an optical component and several optical touch apparatuses are also provided. Taking Taiwan Patent Publication No. 200841057 as an example, it discloses a manufacturing method of a stamper. The method mainly includes following steps. First, ultra-violet (UV) light cured glue is sprayed on a substrate and cured to form a three-dimensional pattern. Thereafter, a stamper is formed on the substrate with a pattern opposite to the three-dimensional pattern. Finally, a light guide plate having a pattern the same as the three-dimensional pattern is produced by using the stamper. 
     Besides, Taiwan Patent Publication No. 200841227 discloses an optical touch apparatus. The optical touch apparatus mainly includes a light source, a light guide module, and an image sensing module. The light source emits light into the light guide module, and the light guide module transmits a moving state of an input device to the image sensing module. After sensing optical information generated by the light guide module, the image sensing module generates an electronic signal according to the optical information and then transmits the electronic signal to a processing circuit. 
     In addition, Taiwan Patent No. M359718 discloses a side type backlight module which includes a plurality of light emitting diodes (LEDs), a light guide plate, a brightness enhancement film, and a diffusion film. Each of the LEDs has a light emitting surface which faces the same direction. The light guide plate is disposed at one side of the LEDs and has a light incident surface, a light exit surface, and a bottom surface. The light incident surface faces the light emitting surfaces of the LEDs. The light exit surface is connected to one side of the light incident surface. The bottom surface of the LED is opposite to the light exit surface and connected to the other side of the light incident surface. Besides, the bottom surface has a plurality of optical microstructures and a plurality of flat areas. The flat areas have a common boundary with the light incident surface. Each of the flat areas is corresponding to the light emitting surfaces of the LEDs. 
     Furthermore, Taiwan Patent Publication No. 200846996 discloses a touch panel with an infrared ray source and an array of infrared ray sensors to detect objects in contact with, or close to, the touchable surface of the panel. The touch panel may be operated in both reflective and shadow modes. 
     U.S. Pat. No. 4,868,912 also discloses a touch panel system. The touch panel system has a plurality of light emitting elements and a plurality of light receiving elements surrounding a display area, such that a touch position corresponding to an object is determined. 
     Similarly, U.S. Pat. No. 6,690,363 discloses a touch screen which has a plurality of emitters and a plurality of detectors surrounding a display screen, so that a touch position corresponding to an object is determined. 
     However, since each of the frameworks mentioned above requires lots of light emitting devices and many sensors, the fabricating cost is unlikely to be lowered. Moreover, the numbers of light emitting devices and sensors depends on a size of a panel. Thus, the larger the display panel is, the greater the number of the light emitting devices and the sensors are required. 
     SUMMARY OF THE INVENTION 
     The invention provides an optical touch apparatus for determining a position of a touch object in an optical manner. 
     The invention provides an optical touch display apparatus which determines a position of a touch object in an optical manner. 
     Other objects and advantages of the invention can be further illustrated by the technical features broadly embodied and described as follows. 
     In order to achieve one or a portion of or all of the objects or other objects, one embodiment of the invention provides an optical touch apparatus adapted to a display apparatus. The display apparatus has a display area. The optical touch apparatus includes at least one light source, at least one light guide unit, and at least one optical detector. The light source is disposed beside the display area and capable of providing a light beam. The light guide unit is disposed beside the display area in a transmission path of the light beam. The light guide unit has a first surface, a second surface, and a light incident surface. The second surface is opposite to the first surface. The light incident surface is connected with the first surface and the second surface. The light beam is capable of entering the light guide unit through the light incident surface and being transmitted to a sensing space in front of the display area through the first surface. The optical detector is disposed beside the display area to sense an intensity variation of the light beam in the sensing space. 
     Another embodiment of the invention further provides an optical touch display apparatus which includes the above-mentioned display apparatus and optical touch apparatus. 
     Based on the above, since each of the light guide units according to the embodiments of the invention provides a uniform light source, the numbers of the light sources and optical detectors disposed beside the display area are able to be reduced. Besides, the touch position of the touch object relative to the display area is able to be determined according to the intensity variation of the light beam sensed by the optical detector. 
     Other objectives, features and advantages of the present invention will be further understood from the further technological features disclosed by the embodiments of the present invention wherein there are shown and described preferred embodiments of this invention, simply by way of illustration of modes best suited to carry out the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
         FIG. 1  is a top view of an optical touch display apparatus in an embodiment of the invention. 
         FIG. 2  is a schematic cross-sectional view of the optical touch display apparatus along line I-I of  FIG. 1 . 
         FIG. 3  is a perspective schematic view of the light guide unit of  FIG. 1 . 
         FIG. 4A  is a top view of the light guide unit and the light source along x-direction of  FIG. 3 . 
         FIG. 4B  illustrates an irradiance distribution of a light beam in a sensing space along y-direction after being emitted from the light guide unit. 
         FIG. 5A  is a top view of a surface S 6  of the light guide unit of  FIG. 3 . 
         FIG. 5B  illustrates a distribution of radiant intensity versus light emitting angle when a light beam is emitted from the surface. 
         FIG. 6A  is a top view of a surface S 6  of a light guide unit in another embodiment of the invention. 
         FIG. 6B  illustrates another distribution of radiant intensity versus light emitting angle when a light beam is emitted from the surface. 
         FIG. 6C  is a top view of a surface S 6  of a light guide unit in another embodiment of the invention. 
         FIG. 7A  is a top view of a light guide unit and a lens along y-direction in another embodiment of the invention. 
         FIG. 7B  illustrates a distribution of radiant intensity versus light emitting angle when a light beam passes through a light guide unit, an air gap, and a lens. 
         FIG. 8A  is a top view of a light guide unit, a lens, and a reflective unit along y-direction in another embodiment of the invention. 
         FIG. 8B  illustrates another distribution of radiant intensity versus light emitting angle when a light beam passes through a light guide unit, an air gap, and a lens. 
         FIG. 9A  is a top view of a light guide unit, a reflective unit, and a front frame along y-direction in another embodiment of the invention. 
         FIG. 9B  is a top view of a light guide unit, a reflective unit, and a front frame along y-direction in another embodiment of the invention. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” etc., is used with reference to the orientation of the Figure(s) being described. The components of the present invention can be positioned in a number of different orientations. As such, the directional terminology is used for purposes of illustration and is in no way limiting. On the other hand, the drawings are only schematic and the sizes of components may be exaggerated for clarity. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention. Also, it is to be understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. Similarly, the terms “facing,” “faces” and variations thereof herein are used broadly and encompass direct and indirect facing, and “adjacent to” and variations thereof herein are used broadly and encompass directly and indirectly “adjacent to”. Therefore, the description of “A” component facing “B” component herein may contain the situations that “A” component directly faces “B” component or one or more additional components are between “A” component and “B” component. Also, the description of “A” component “adjacent to” “B” component herein may contain the situations that “A” component is directly “adjacent to” “B” component or one or more additional components are between “A” component and “B” component. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive. 
       FIG. 1  is a top view of an optical touch display apparatus  100  in an embodiment of the invention.  FIG. 2  is a schematic cross-sectional view of the optical touch display apparatus  100  along line I-I of  FIG. 1 . Referring to both  FIG. 1  and  FIG. 2 , the optical touch display apparatus  100  includes a display apparatus  110  and an optical touch apparatus  120 . The display apparatus  110  has a display area  112  and a sensing space P is in front of the display area  112 . Besides, the display apparatus  110  of this embodiment further includes a front frame  114 . In the embodiment, the display area  112  is disposed in the front frame  114  and the optical touch apparatus  120  is disposed on the front frame  114 . 
     As shown in  FIG. 1 , the optical touch apparatus  120  includes at least one light source  122   b , at least one light guide unit  124   b , and at least one optical detector  126   a . The light source  122   b  is disposed beside the display area  112  and capable of providing a light beam L 1 . In the embodiment, the light beam L 1  is, for example, invisible light and the light source  122   b  is an infrared light emitting diode (IR-LED), for example. 
     Referring to  FIG. 1 , the light guide unit  124   b  is disposed in a transmission path of the light beam L 1 . On the other hand, the optical touch apparatus  120  of the embodiment includes a plurality of light sources, e.g. light sources  122   a ˜ 122   c  (three light sources are schematically shown in  FIG. 1 ). The optical detector  126   a  is disposed beside the display area  112  to sense an intensity variation of a light beam (e.g. a light beam L 2 ) in the sensing space P. Otherwise, the optical touch apparatus  120  further includes a plurality of light guide units and a plurality of optical detectors. For example, light guide units  124   a ˜ 124   c  (three light guide units are schematically shown in  FIG. 1 ) and optical detectors  126   a  and  126   b  (two optical detectors are schematically shown in  FIG. 1 ). The light guide units  124   a ˜ 124   c  and the corresponding light sources  122   a ˜ 122   c  are disposed at different sides of the display area  112 , respectively. Each of the optical detectors  126   a ˜ 126   b  is disposed beside the display area  112  and faces one of the light guide units  124   a ˜ 124   c . Specifically, the optical detector  126   a  is disposed beside the display area  112  and faces the light guide unit  124   a , and the optical detector  126   b  is disposed beside the display area  112  and faces the light guide unit  124   b . The optical detector  126   a  senses, for example, an intensity variation of the light beam L 2  emitted from the light guide unit  124   a  along y-direction. The optical detector  126   b  senses, for example, an intensity variation of the light beam L 1  emitted from the light guide unit  124   b  along x-direction. 
     Furthermore, the optical touch apparatus  120  of the embodiment further includes a processing unit  130  electronically connected with the optical detector  126   a  or the optical detector  126   b . Referring to  FIG. 1  and  FIG. 2 , when a touch object  140  (e.g. a finger) enters the sensing space P, the processing unit  130  determines a position (x, y) of the touch object  140  relative to the display area  112  according to the intensity variations of the light beam emitted from the light guide unit corresponding to different directions. 
       FIG. 3  is a schematic view of the light guide unit  124   a  of  FIG. 1 . As shown in  FIG. 3 , the light guide unit  124   a  has a surface S 1 , a surface S 2 , and a light incident surface S 3 . The surface S 2  is opposite to the surface S 1 . The light incident surface S 3  is connected with the surface S 1  and the surface S 2 . Referring to both  FIG. 1  and  FIG. 3 , the light beam L 2  from the light source  122   a  enters the light guide unit  124   a  through the light incident surface S 3  and is transmitted to the sensing space P in front of the display area  112  through the surface S 1 . In other words, in the embodiment, the surface S 1  of the light guide unit  124   a  is a light emitting surface. 
     Moreover, the light guide unit  124   a  further has a surface S 4 , a surface S 5 , and a surface S 6 . As shown in  FIG. 3 , the surface S 4  of the light guide unit  124   a  is connected with the light incident surface S 3 , the surface S 1 , and the surface S 2 . The surface S 5  is opposite to the surface S 4  and connected with the light incident surface S 3 , the surface S 1 , and the surface S 2 . On the other side, the surface S 6  is opposite to the light incident surface S 3 . 
       FIG. 4A  is a top view of the light guide unit  124   a  and the light source  122   a  along x-direction of  FIG. 3 . As shown in  FIG. 4A , the surface S 2  has a plurality of microstructures  128 . A number density of the microstructures  128  close to the light source  122   a  is less than a number density of the microstructures  128  away from the light source  122   a . Besides, the microstructures  128  are, for example, printing dots or etching dots. The printing dots are, for example, protrusions or protruding patterns. The etching dots are, for example, recessions or grooves. The light beam L 2  at the light emitting surface (i.e. surface S 1 ) of the light guide unit  124   a  is able to emit uniformly by adjusting the number density of the microstructures  128  on the surface S 2 , such that the light guide unit  124   a  is capable of providing a uniform light source along y-direction. It should be noted that, the width a of the light guide unit  124   a  along z-direction may be reduced so as to enhance the thinness of the optical touch apparatus  120 . 
       FIG. 4B  illustrates an irradiance distribution of the light beam L 2  emitted from the light guide unit  124   a  in the sensing space P along y-direction. The irradiance (W/m 2 ) is power of light irradiating on a unit area within a unit time. From  FIG. 4B , the microstructures  128  of the light guide unit  124   a  enhance the uniformity of the irradiance of the light beam L 2  along y-direction. It should be noted that, the surface S 1 , the surface S 4 , the surface S 5 , and the surface S 6  (shown in  FIG. 3 ) may have the above-mentioned microstructures  128  in another embodiment. In other words, in another embodiment, at least one of the surface S 1 , the surface S 2 , the surface S 4 , the surface S 5 , and the surface S 6  has a plurality of microstructures  128  so as to enhance the uniformity of the irradiance of the light beam L 2  at the light emitting surface (i.e. surface S 1 ) of the light guide unit  124   a  along y-direction. On the other hand, the light guide units  124   b  and  124   c  of  FIG. 1  may have structures the same as the structure of the light guide unit  124   a . Thus, the light guide units  124   b  and  124   c  may respectively provide uniform light sources at other two sides of the display area  112 , such that the uniformity of the irradiance in the sensing space P is able to be enhanced as well. The structures of the light guide units  124   b  and  124   c  of the embodiment may be referred to the structure of the light guide unit  124   a . Therefore, no further description is provided hereinafter. 
     Referring to both  FIG. 1  and  FIG. 3 , in the embodiment, the light source  122   a  is disposed at a corner A of the display area  112  and the light guide unit  124   a  is disposed at a side  112   a  of the display area  112 . In addition, the surface S 1  faces the sensing space P. When the touch object  140  enters the sensing space P, the touch object  140  shields off a part of the light beam L 2  emitted from the light guide unit  124   a , such that the optical detector  126   a  senses an intensity variation of the light beam L 2  along y-direction. In other words, the optical detector  126   a  senses a dark point along y-direction, such that coordinate y of a touch position is determined according to the dark point. Similarly, the touch object  140  also shields off a part of the light beam L 1  emitted from the light guide unit  124   b , such that the optical detector  126   b  senses another intensity variation of the light beam L 1  along x-direction. In other words, the optical detector  126   b  senses a dark point along x-direction, such that coordinate x of the touch position is determined according to the dark point. Then, the processing unit  130  determines the position (x, y) of the touch object  140  relative to the display area  112  according to the intensity variations along the two directions. 
     It should be noted that, by properly rotating the optical detector  126   b , the optical detector  126   b  is able to sense the intensity variation of light beam L 2  emitted from the light guide unit  124   a  along y-direction in the sensing space P. In other words, in another embodiment, the optical detector  126   a  and the optical detector  126   b  may be able to respectively sense the intensity variations along x-direction and y-direction in the sensing space P according to their location and the direction they face. Thus, the position (x, y) of the touch object  140  is determined according to the intensity variations along different directions respectively sensed by the optical detector  126   a  and the optical detector  126   b . In other words, the locations of the optical detector  126   a  and the optical detector  126   b  are not limited to the locations as shown in  FIG. 1 , and may be varied by request. 
       FIG. 5A  is a top view of the surface S 6  of the light guide unit  124   a  in  FIG. 3 .  FIG. 5B  illustrates a distribution of radiant intensity versus light emitting angle when the light beam L 2  is emitted from the surface S 1  of the light guide unit  124   a  of  FIG. 3 . Referring to both  FIG. 1  and  FIG. 5B , as shown in  FIG. 5B , in an embodiment, when a light emitting angle of the light beam L 2  is 90° (i.e. the light beam L 2  is emitted along positive x-direction), the radiant intensity (W/sr) is 130 W/sr approximately. Specifically, light emitting angles 80° and 100° of  FIG. 5B  represent that the light beam L 2  is emitted from the surface S 1  at an angle of 10° relative to positive x-direction. On the other hand, light emitting angles 60° and 120° of  FIG. 5B  represent that the light beam L 2  is emitted from the surface S 1  at an angle of 30° relative to positive x-direction. As shown in  FIG. 5B , the radiant intensity of the light beam L 2  in the sensing space P decreases as the angle between a light transmission path and positive x-direction increases. 
       FIG. 6A  is a top view of a surface S 6  of a light guide unit  224   a  in another embodiment of the invention. The light guide unit  224   a  is similar to the light guide unit  124   a  of  FIG. 5A , while the major difference lies in that the surface S 1  is a convex surface. The function of the convex surface is similar to the function of a lens. That is, the convex surface is able to concentrate a light emitting angle of a light beam, e.g. the light beam L 2  of  FIG. 1 .  FIG. 6B  illustrates another distribution of radiant intensity versus light emitting angle when the light beam L 2  is emitted from the surface S 1  of the light guide unit  224   a  of  FIG. 6A . As shown in  FIG. 6B , in an embodiment, when a light emitting angle of the light beam L 2  is 90°, the radiant intensity (W/sr) is 280 W/sr approximately, which is higher than (approximately 2 times of) the radiant intensity corresponding to the light beam L 2  emitted from the surface S 1  of the light guide unit  124   a  in  FIG. 5A . In other words, compared with the light guide unit  124   a  of  FIG. 5A , the light guide unit  224   a  is able to concentrate light emitting angles of the light beam L 2  towards positive x-direction, such that the radiant intensity of the light beam L 2  along the positive x-direction is enhanced. Besides, in another embodiment, as shown in  FIG. 6C , the surface S 1  of the light guide unit  324   a  may be a plurality of prism structures  226 , the prism structures  226  are able to concentrate the light emitting angle of the light beam L 2  towards positive x-direction as well. 
       FIG. 7A  is a top view of a light guide unit  124   a  and a lens  426  along y-direction in another embodiment of the invention. As shown in  FIG. 7A , the lens  426  is further disposed on the surface S 1  of the light guide unit  124   a . Furthermore, an air gap G is between the lens  426  and the surface S 1 . Thus, the light beam L 2  of FIG.  1  passes through the air gap G and is then transmitted to the lens  426  after emitted from the light emitting surface (i.e. surface S 1 ).  FIG. 7B  illustrates a distribution of radiant intensity versus light emitting angle when the light beam L 2  passes through the light guide unit  124   a , the air gap G, and the lens  426 . As shown in  FIG. 7B , in an embodiment, when a light emitting angle of the light beam L 2  is 90°, the radiant intensity is about 320 W/sr, which is higher than the radiant intensity (280 W/sr) corresponding to the light beam L 2  emitted from the surface S 1  of the light guide unit  224   a  in  FIG. 6A . 
       FIG. 8A  is a top view of the light guide unit  124   a , the lens  426 , and a reflective unit  526  along y-direction in another embodiment of the invention. As shown in  FIG. 8A , the reflective unit  526  is further disposed on the light guide unit  124   a . The reflective unit  526  is disposed on at least one of the surfaces S 4  and S 5 , such that leakages of the light beam L 2  (shown in  FIG. 1 ) from the surface S 4  and the surface S 5  are reduced. 
     In the embodiment, the reflective unit  526  includes, for example, two reflective sheets  526   a  and  526   b , and the reflective sheets  526   a  and  526   b  are respectively disposed on the surface S 4  and the surface S 5 . It should be noted that, the reflective unit  526  may be disposed on the surface S 2  and the surface S 6  (shown in  FIG. 3 ) of the light guide unit  124   a  in another embodiment. In other words, the reflective unit  526  is disposed on at least one of the surface S 2 , the surface S 4 , the surface S 5 , and the surface  6 . That is to say, all surfaces of the light guide unit  124   a  may be covered with the reflective unit  526  except the light incident surface S 3  and the light emitting surface (i.e. surface S 1 ). The reflective unit  526  is, for example, a white reflective sheet, an aluminum reflective sheet, an aluminum film, or a sliver film. 
     Besides, the lens  426  of  FIG. 8A  is not only disposed on the surface S 1  but also disposed beside the reflective sheets  526   a  and  526   b . Moreover, the air gap G is between the lens  426  and the surface S 1 . Referring to both  FIG. 1  and  FIG. 8A , the light beam L 2  from the light source  122   a  is reflected several times between the two reflective sheets  526   a  and  526   b  and then emitted from the light emitting surface (i.e. surface S 1 ) in a proper light emitting angle. Then, the light beam L 2  passes through the air gap G first and then is transmitted to the lens  426 . Since the reflective sheets  526   a  and  526   b  are respectively disposed on the upper surface S 4  and the bottom surface S 5 , the power of the light beam L 2  emitted from the light emitting surface (i.e. surface S 1 ) is enhanced. 
       FIG. 8B  illustrates another distribution of radiant intensity versus light emitting angle when the light beam L 2  passes through the light guide unit  124   a , the air gap G, and the lens  426 . As shown in  FIG. 8B , in an embodiment, when a light emitting angle of the light beam L 2  is 90°, the radiant intensity is 360 W/sr approximately, which is higher than the radiant intensity (320 W/sr) corresponding to the light beam L 2  emitted from the surface S 1  of the light guide unit  124   a  in  FIG. 7B . In other words, by using the light guide unit  124   a  together with the reflective unit  526 , the radiant intensity of light beam L 2  along positive x-direction is enhanced. 
     It should be noted that, the figures from optical experiments shown in  FIG. 4B ,  FIG. 5B ,  FIG. 6B ,  FIG. 7B , and  FIG. 8B  are not used to limited the invention. One of ordinary skill in the art may modify data to obtain different figures from optical experiments after referring to the invention without departing from the scope of the invention. Those modifications still fall within the scope of the invention. 
       FIG. 9A  is a top view of the light guide unit  124   a , the reflective unit  526 , and a front frame  626  along y-direction in another embodiment of the invention. As shown in  FIG. 9A , the front frame  626  is further disposed on the light guide unit  124   a . The front frame  626  includes a lens portion  626   a  and a cover portion  626   b . The cover portion  626   b  covers the surface S 4 . The lens portion  626   a  is formed with the cover portion  626   b  integrally and disposed on the surface S 1 . 
     The function of the lens portion  626   a  of the front frame  626  is the same as the function of the lens  426 . Namely, the lens portion  626   a  is able to concentrate the light emitting angle of the light beam L 2  from the surface S 1  towards positive x-direction. The cover portion  626   b  has a function for protection. Besides, a color master may be added into the front frame  626 , for example. Thus, the artistry-featuring look of the optical touch display apparatus is enhanced. Furthermore, an infrared ray is able to pass through the color master. That is to say, the light beam L 2  is capable of passing through the lens portion  626   a  to the sensing space P, such that the sensing function of the optical detectors  126   a  and  126   b  are not affected. 
     As shown in  FIG. 9A , the reflective unit  526  of  FIG. 8A  is further disposed on the light guide unit  124   a  of the embodiment, such that the power of the light beam L 2  emitted from the light emitting surface (i.e. surface S 1 ) is enhanced. In other words, the front frame  626  of the embodiment covers the light guide unit  124   a  and the reflective unit  526 . However, in another embodiment, the reflective unit  526  may not be disposed on the light guide unit  124   a . That is, the front frame  626  may be directly disposed on the light guide unit  124   a.    
       FIG. 9B  is a top view of the light guide unit  124   a , the reflective unit  526 , and the front frame  626  along y-direction in another embodiment of the invention.  FIG. 9A  and  FIG. 9B  are similar, but the major difference of them lies in the shape of the lens portion  626   a  of the front frame  626 . It should be noted that the shape of the lens portion  626   a  of the front frame  626  may be designed according to the actual requirements.  FIG. 9A  and  FIG. 9B  are only used for reference, and not intended to limit the invention. 
     In Summary, the embodiment or embodiments of the invention may have at least one of the following advantages: the optical touch apparatus and the optical touch display apparatus determine the positions of the touch objects by using the optical detectors for sensing the intensity variations of the light beams. Since each light guide unit according to the embodiments of the invention provides an uniform light source, the number of the light sources and optical detectors disposed beside the display area are able to be reduced, the light guide unit not only reduces the fabricating cost but also is advantageous to a variation in dimension of the apparatus. Besides, because no complicated components and process are required in the fabrication of the optical touch apparatuses of the embodiments, the fabricating cost thereof is far lower than the fabricating cost of the resistance or capacitance touch apparatus. Furthermore, the ultra-thin light guide unit also enhances the thinness of the optical touch apparatus. 
     The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form or to exemplary embodiments disclosed. Accordingly, the foregoing description should be regarded as illustrative rather than restrictive. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. The embodiments are chosen and described in order to best explain the principles of the invention and its best mode practical application, thereby to enable persons skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use or implementation contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Therefore, the term “the invention”, “the present invention” or the like does not necessarily limit the claim scope to a specific embodiment, and the reference to particularly preferred exemplary embodiments of the invention does not imply a limitation on the invention, and no such limitation is to be inferred. The invention is limited only by the spirit and scope of the appended claims. The abstract of the disclosure is provided to comply with the rules requiring an abstract, which will allow a searcher to quickly ascertain the subject matter of the technical disclosure of any patent issued from this disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Any advantages and benefits described may not apply to all embodiments of the invention. It should be appreciated that variations may be made in the embodiments described by persons skilled in the art without departing from the scope of the present invention as defined by the following claims. Moreover, no element and component in the present disclosure is intended to be dedicated to the public regardless of whether the element or component is explicitly recited in the following claims.