Abstract:
A display device includes a display panel and a directional antenna. The directional antenna is disposed behind or under the display panel for radiating or receiving wireless signals. The radiating path of the directional antenna is at a specific angle with respect to a horizontal plane for receiving surrounding wireless signals. Or, the signals radiated from the directional antenna may be reflected or refracted to regions above or in front of the display device by a back-side barrier or penetrate a back-side barrier which does not cause large electromagnetic degradation, thereby receiving wireless signals originated from the front-side or back-side of the display device.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is related to a wireless display device, and more particularly, to a flat panel wireless display device having directional antenna. 
         [0003]    2. Description of the Prior Art 
         [0004]    As telecommunication medium for entertainment, information, transmitting and receiving news in modern society, televisions (TVs) have become commonplace in homes, businesses and institutions. The installation of traditional cable TVs may be complicated due to the arrangement of coaxial cables or optical fibers. In contrast, wireless TVs capable of receiving multi-media data via built-in antenna have become more and more popular. 
         [0005]    In a wireless system, antennas occupy more space than other components. In a traditional display device with wireless antennas (such as TV or notebook computer), metallic omnidirectional embedded antennas are normally disposed inside the side frame of the display device in order to communicate with a nearby access point (AP). However, with rapid shrinkage in device size, there is less room available for traditional embedded antennas since more and more flat panel display devices adopt narrow side frames or no side frame at all. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention provides a display device including a housing; a display panel in the housing; and a first directional antenna disposed in the housing behind or under the display panel for radiating a wireless signal, wherein a first radiating path of the first directional antenna is at a specific angle with respect to a horizontal plane. 
         [0007]    The present invention also provides an electronic device having a directional antenna. The directional antenna includes a substrate; a transmitting element disposed on the substrate along a first direction for transmitting signals; a first radiating element disposed on the substrate along a second direction perpendicular to the first direction for providing a first radiation pattern of a first band and including a first terminal structure on a far side away from the transmitting element and at a first predetermined angle with respect to the second direction; a second radiating element disposed on the substrate along the second direction for providing a second radiation pattern of a second band and for directing the radiation pattern of the first band along the first direction; and a first reflecting element disposed on the substrate along the second direction for reflecting the first radiation pattern of the first band towards the first direction. 
         [0008]    The present invention also provides an electronic device including a housing and a first directional antenna. The first directional antenna is disposed in the housing for radiating a wireless signal, wherein a first radiating path of the first directional antenna is at a first specific angle with respect to a horizontal plane, the first directional antenna including a first radiating element and a second radiating element, the first radiating element providing a first radiation pattern of a first band, and the second radiating element providing a second radiation pattern of a second band and reflecting the first radiation pattern of the first band. 
         [0009]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1A  is a side-view diagram of a wireless display device according to a first embodiment of the present invention. 
           [0011]      FIG. 1B  is a rear-view diagram of the wireless display device according to the first embodiment of the present invention. 
           [0012]      FIG. 2A  is a side-view diagram of a wireless display device according to a second embodiment of the present invention. 
           [0013]      FIG. 2B  is a rear-view diagram of the wireless display device according to the second embodiment of the present invention. 
           [0014]      FIG. 3A  is a side-view diagram of a wireless display device according to a third embodiment of the present invention. 
           [0015]      FIG. 3B  is a rear-view diagram of the wireless display device according to the third embodiment of the present invention. 
           [0016]      FIGS. 4A and 4B  are diagrams illustrating the operation of the wireless display device with various dispositions. 
           [0017]      FIG. 5A  is a side-view diagram of a wireless display device according to a fourth embodiment of the present invention. 
           [0018]      FIG. 5B  is a side-view diagram of a wireless display device according to the fifth embodiment of the present invention. 
           [0019]      FIG. 6A  is a side-view diagram of a wireless display device according to a sixth embodiment of the present invention. 
           [0020]      FIG. 6B  is a side-view diagram of a wireless display device according to the sixth embodiment of the present invention. 
           [0021]      FIGS. 7 ,  8 A,  8 B and  9  are diagrams of the directional antenna according to embodiments of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]      FIG. 1A  is a side-view diagram of a wireless display device  100  according to an embodiment of the present invention.  FIG. 1B  is a rear-view diagram of the wireless display device  100 . The wireless display device  100  includes a display panel  10 , a directional multi-frequency antenna  20 , a fixture  30 , a back housing  40 , and a base  80 . The fixture  30 , to which the directional multi-frequency antenna  20  maybe attached, is disposed on the backside of the display panel  10 , so the path of the wireless signals radiated by the directional antenna  20  is at a specific angle θ with respect to the viewing angle (or horizontal plane) of the display panel  10 . The back housing  40  may include plastic material for containing and protecting the display panel  10 , the directional multi-frequency antenna  20 , the fixture  30 , or other internal components (not shown) of the wireless display device  100 . 
         [0023]      FIG. 2A  is a side-view diagram of a wireless display device  200  according to an embodiment of the present invention.  FIG. 2B  is a rear-view diagram of the wireless display device  200 . Having similar structures, the wireless display device  200  differs from the wireless display device  100  in that the back housing  40  is made of metallic material and includes an opening  50  to allow wireless signals to pass. Therefore, the metallic back housing  40  may protect the display panel  10 , the directional multi-frequency antenna  20 , the fixture  30 , or other internal components (not shown) of the wireless display device  200  without blocking the radiating path of the directional multi-frequency antenna  20 . 
         [0024]      FIG. 3A  is a side-view diagram of a wireless display device  300  according to an embodiment of the present invention.  FIG. 3B  is a rear-view diagram of the wireless display device  300 . Having similar structures, the wireless display device  300  differs from the wireless display device  100  in that the back housing  40  is made of metallic material and includes a plastic cover  60  to allow wireless signals to pass. Therefore, the metallic back housing  40  may protect the display panel  10 , the directional multi-frequency antenna  20 , the fixture  30 , or other internal components (not shown) of the wireless display device  300  without blocking the radiating path of the directional multi-frequency antenna  20 . 
         [0025]      FIGS. 4A and 4B  are diagrams illustrating the operation of the wireless display device  100 / 200 / 300  with various dispositions according to the present invention. In  FIG. 4A , the wireless display device  100 / 200 / 300  is disposed in open space, or surrounded by objects which are penetrable by radio signals. An access point AP 1  is arranged in front of the wireless display device, while an access point AP 2  is arranged behind the wireless display device. The radiation patterns of the wireless display device  100 / 200 / 300 , the access point AP 1  and the access point AP 2  are represented by RP 0 ˜RP 2 , respectively. Since the radiating path of the access point AP 1  is blocked by the wireless display device  100 / 200 / 300 , only partial radiation pattern RP 1  may arrive to regions above or behind the display device  100 / 200 / 300 . In one of the embodiments according to the present invention, the radiating path of the directional antenna  20  is at the specific angle θ with respect to the horizontal plane. Therefore, the radiation patterns RP 0  and RP 1  may intersect each other in regions behind the display device  100 / 200 / 300 , thereby allowing the display device  100 / 200 / 300  to communicate with the access point AP 1 . Meanwhile, the radiation patterns RP 0  and RP 2  may also intersect each other in regions behind the display device  100 / 200 / 300 , thereby allowing the display device  100 / 200 / 300  to communicate with the access point AP 2 . 
         [0026]    In  FIG. 4B , the wireless display device  100 / 200 / 300  is hanged or disposed in front of other structures. In other words, the back of the wireless display device  100 / 200 / 300  is adjacent to an object  70  non-penetrable to radio signals. An access point AP 1  is arranged in front of the wireless display device. The radiation patterns of the wireless display device  100 / 200 / 300  and the access point AP 1  are represented by RP 0  and RP 1 , respectively. Since the radiating path of the access point AP 1  is blocked by the wireless display device  100 / 200 / 300  and the object  70 , only partial radiation pattern RP 1  may arrive to regions above the display device  100 / 200 / 300 . In one of the embodiments according to the present invention, the radiating path of the directional antenna  20  is at the specific angle θ with respect to the viewing angle (or horizontal plane) of the display panel  10 . Therefore, the radiation pattern RP 0  may be reflected or refracted to regions above the display device  100 / 200 / 300  and intersect with the radiation pattern RP 1 , thereby allowing the display device  100 / 200 / 300  to communicate with the access point AP 1 . 
         [0027]      FIG. 5A  is a side-view diagram of a wireless display device  400  according to an embodiment of the present invention.  FIG. 5B  is a side-view diagram of a wireless display device  500  according to an embodiment of the present invention. Having similar structures as the wireless display device  100 / 200 / 300 , a directional antenna  20  is disposed on the back of the display panel  10  of the wireless display device  400 / 500 , so that the radiating path of the directional antenna  20  is at a specific angle θ with respect to the horizontal plane, as depicted in  FIGS. 1A-1B . However, the embodiments of  FIGS. 5A and 5B  include multiple directional antennas, wherein the wireless display device  400  further includes a directional antenna  21  and the wireless display device  500  further includes two directional antennas  21  and  22 . In the wireless display device  400 , the directional antenna  21  is disposed on a specific side of the display panel  10  or behind the display panel  10  on a specific side at a specific angle θ′ with respect to the horizontal plane, so as to provide a radiation pattern in regions beside the display device  400 . The directional antennas  21  and  22  may improve the quality of signal communication. In the wireless display device  500 , the directional antennas  21  and  22  are disposed on both sides of the display panel  10  or behind the display panel  10  on both sides at a specific angle θ′ with respect to the horizontal plane, so as to provide radiation patterns in regions beside the display device  400 . The directional antennas  2123  may improve the quality of signal communication. 
         [0028]      FIG. 6A  is a side-view diagram of a wireless display device  600  according to an embodiment of the present invention.  FIG. 6B  is a side-view diagram of a wireless display device  700  according to an embodiment of the present invention. Similar to the embodiments depicted in  FIGS. 1A-3A , the wireless display device  600 / 700  also includes a display panel (not shown), a fixture (not shown), a back housing  40 , and a base  80 . However, the wireless display device  600  includes a directional antenna  21 , and the wireless display device  700  includes two directional antennas  21  and  22 . In the wireless display device  600 , the directional antenna  21  is disposed beside the base  80  or behind the base  80  on a specific side at a specific angle θ′ with respect to the horizontal plane, so as to provide a radiation pattern in regions beside the wireless display device  600 . In the wireless display device  700 , the directional antennas  21  and  22  are disposed on both sides of the base  80  or behind the base  80  on both sides at a specific angle θ′ with respect to the horizontal plane, so as to provide radiation patterns in regions beside the wireless display device  700 . Meanwhile, in an embodiment of the present invention, the directional antenna  21  may also be disposed inside the hanger of the wireless display device, or the base  80  in which the directional antenna  21  is disposed may be stretchable and folded towards the back-side of the wireless display device for serving as the hanger. The directional antenna  21  may still provide a radiation pattern in regions beside the wireless display device. 
         [0029]      FIGS. 7 ,  8 A and  8 B are diagrams of the directional antenna  20  according to an embodiment of the present invention.  FIG. 7  is a diagram illustrating the overall structure of the directional antenna  20 .  FIG. 8A  is a diagram illustrating the circuit layout on the top-side of the directional antenna  20 .  FIG. 8B  is a diagram illustrating the circuit layout on the bottom-side of the directional antenna  20 . In this embodiment, the directional antenna  20  is a dual-frequency antenna which includes radiating elements  21 A,  21 B,  22 A and  22 B, reflecting elements  23 A and  23 B, transmitting elements  24 A and  24 B, and a substrate  25 . The substrate  25  may be an FR 4  double-sided fiberglass having a top circuit layer and a bottom circuit layer. The radiating element  21 A, the radiating element  22 A, the reflecting element  23 A, and the transmitting element  24 A are fabricated on the top circuit layer, as depicted in  FIG. 8A . The radiating element  21 B, the radiating element  22 B, the reflecting element  23 B, and the transmitting element  24 B are fabricated on the bottom circuit layer, as depicted in  FIG. 8B . The transmitting elements  24 A and  24 B are coupled to a signal feed point FEED for transmitting signals to the radiating elements  21 A,  21 B,  22 A and  22 B. 
         [0030]    X A  represents the length of the radiating element  21 A. X B  represents the length of the radiating element  21 B.  21 A′ represents a terminal structure of the radiating element  21 A on the far side away from the transmitting element  24 A.  21 B′ represents a terminal structure of the radiating element  21 B on the far side away from the transmitting element  24 B. The terminal structure  21 A′ is disposed at a predetermined angle θ A  with respect to the X-axis, while the terminal structure  21 B′ is disposed at a predetermined angle θ B  with respect to the X-axis. The radiating elements  21 A and  21 B form a double-sided printed dipole antenna which provides a first radiation pattern of a first band (such as 2.4 GHz˜2.5 GHZ) having a wavelength λ 1 , wherein (X A +X B )≈λ 1 /2. The reflecting element  23 A/ 23 B is configured to reflect the first radiation pattern of the first band along the Y-axis. The distance D 1  between the reflecting element  23 A/ 23 B and the radiating element  21 A/ 21 B is in the range of 0.15λ 1  to 0.25λ 1 . The radiating elements  22 A and  22 B are directors of the radiating elements  21 A and  21 B and configured to direct the first radiation pattern of the first band along the Y-axis. The distance D 2  between the radiating element  21 A/ 21 B and the radiating element  22 A/ 22 B is in the range of 0.15λ 1  to 0.25λ 1 . The radiation patterns of the radiating elements  21 A and  21 B may have higher directivity by adjusting the predetermined angles θ A  and θ B , at which the terminal structures  21 A′ and  21 B′ are disposed with respect to the X-axis, respectively. The predetermined angles θ A  and θ B  may be between 0˜90 degrees. 
         [0031]    Y A  represents the length of the radiating element  22 A. Y B  represents the length of the radiating element  22 B. In addition to functioning as the directors of the radiating elements  21 A and  21 B, the radiating elements  22 A and  22 B also form a double-sided printed dipole antenna which provides a second radiation pattern of a second band (such as 5 GHz˜6 GHZ) having a wavelength λ 2 , wherein (Y A +Y B )≈λ 2 /2. At this time, the radiating elements  21 A and  21 B are reflectors of the radiating elements  22 A and  22 B and configured to reflect the second radiation pattern of the second band along the Y-axis. The distance D 1  between the reflecting element  23 A/ 23 B and the radiating element  21 A/ 21 B is in the range of 0.15λ 1  to 0.25λ 1 . The radiating elements  22 A and  22 B are directors of the radiating elements  21 A and  21 B and configured to direct the first radiation pattern of the first band along the Y-axis. The distance D 2  between the radiating element  21 A/ 21 B and the radiating element  22 A/ 22 B is in the range of 0.15λ 2  to 0.25λ 2 . The radiation patterns of the radiating elements  21 A and  21 B may have higher directivity by adjusting the predetermined angles θ A  and θ B , at which the terminal structures  21 A′ and  21 B′ are disposed with respect to the X-axis, respectively. The predetermined angles θ A  and θ B  may be between 0˜90 degrees. 
         [0032]      FIG. 9  is a diagram of the directional antenna  20  according to another embodiment of the present invention. In this embodiment, the directional antenna  20  is a dual-frequency antenna which includes radiating elements  21 A,  21 B,  22 A and  22 B, a reflecting element  23 , transmitting elements  24 A and  24 B, and a substrate  25 . The substrate  25  may be an FR 4  double-sided fiberglass having a single circuit layer. The radiating elements  21 A,  21 B,  22 A and  22 B, the reflecting element  23 , and the transmitting elements  24 A and  24 B are all fabricated on the same circuit layer. The transmitting elements  24 A and  24 B are coupled to a signal feed point FEED for transmitting signals to the radiating elements  21 A,  21 B,  22 A and  22 B. 
         [0033]    X A  represents the length of the radiating element  21 A. X B  represents the length of the radiating element  21 B.  21 A′ represents a terminal structure of the radiating element  21 A on the far side away from the transmitting element  24 A.  21 B′ represents a terminal structure of the radiating element  21 B on the far side away from the transmitting element  24 B. The terminal structure  21 A′ is disposed at a predetermined angle θ A  with respect to the X-axis, while the terminal structure  21 B′ is disposed at a predetermined angle θ B  with respect to the X-axis. The radiating elements  21 A and  21 B form a single-sided printed dipole antenna which provides a first radiation pattern of a first band (such as 2.4 GHz˜2.5 GHZ) having a wavelength λ 1 , wherein (X A +X B )=λ 1 /2. The reflecting element  23  is configured to reflect the first radiation pattern of the first band along the Y-axis. The distance D 1  between the reflecting element  23  and the radiating element  21 A/ 21 B is in the range of 0.15λ 1  to 0.25λ 1 . The radiating elements  22 A and  22 B are directors of the radiating elements  21 A and  21 B and configured to direct the first radiation pattern of the first band along the Y-axis. The distance D 2  between the radiating element  21 A/ 21 B and the radiating element  22 A/ 22 B is in the range of 0.15λ 1  to 0.25λ 1 . The radiation patterns of the radiating elements  21 A and  21 B may have higher directivity by adjusting the predetermined angles θ A  and θ B , at which the terminal structures  21 A′ and  21 B′ are disposed with respect to the X-axis, respectively. The predetermined angles θ A  and θ B  may be between 0˜90 degrees. 
         [0034]    Y A  represents the length of the radiating element  22 A. Y B  represents the length of the radiating element  22 B. In addition to functioning as the directors of the radiating elements  21 A and  21 B, the radiating elements  22 A and  22 B also form a single-sided printed dipole antenna which provides a second radiation pattern of a second band (such as 5 GHz˜6 GHZ) having a wavelength λ 2 , wherein (Y A +Y B )=λ 2 /2. At this time, the radiating elements  21 A and  21 B are reflectors of the radiating elements  22 A and  22 B and configured to reflect the second radiation pattern of the second band along the Y-axis. The distance D 2  between the radiating element  21 A/ 21 B and the radiating element  22 A/ 22 B is in the range of 0.15λ 2  to 0.25λ 2 . 
         [0035]    According to the dielectric constant of the substrate  25  or the signal transmission path, the directional antenna  20  may adopt asymmetric layout (X A ≠X B  and Y A ≠Y B , as depicted in  FIGS. 7 ,  8 A and  8 B) or symmetric layout (X A =X B  and Y A =Y B , as depicted in  FIG. 9 ).  FIGS. 7 ,  8 A,  8 B and  9  are merely embodiments of the present invention and do not limit the scope of the present invention. Meanwhile, the directional antennas  21  and  22  may also adopt the structures depicted in  FIGS. 7 ,  8 A,  8 B and  9 . 
         [0036]    The wireless display device of the present invention may be flat panel TVs with narrow side frames or without side frame. One or multiple directional antennas may be disposed at the back of the display panel  10  or the base  80  so that the radiating path of each directional antenna is at a specific angle θ for receiving wireless signals. Or, when disposed in front of a backside object, the wireless signal radiated by each directional antenna may be refracted or reflected to regions above or in front of the display device for communicating with front-side APs. Therefore, the present invention may provide high quality and high efficiency wireless communication when the wireless display device is disposed in open space or in front of a barrier. 
         [0037]    Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.