Abstract:
There is provided an antenna device having a learning function and capable of searching and memorizing wireless frequency bands. A control circuit is used to automatically control the receiving angle and direction of an antenna set. When the strongest frequency band is found by the antenna set, a remote control is used to control the circuit for recording the current angle and direction into a memory unit. Afterwards, a user can directly select a pre-stored band identification number to conveniently adjust the antenna device to have the best receiving angle and direction the corresponding capable of receiving the band, thereby decreasing the time to adjust the antenna.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an antenna device having a learning function and capable of searching and memorizing wireless frequency bands, and more particularly, to an antenna device capable of automatically searching and adjusting the wireless TV band. 
     2. Description of Related Art 
     The television has become an almost indispensable device for information and entertainment throughout the world. Cable TV, that is, direct feed of stations to our homes instead of using an antenna system has become increasingly popular because of the many stations available via the former. However, in some remote districts, cable TV may not be available because of the high cost involved for the small quantity of homes, and thus the wireless TV is still important. 
     As known, the wireless TV has to be installed with an antenna for receiving the wireless video signal. Conventionally, an outdoor antenna has to be established at a position without being obscured, so as to enable the TV set to receive and display clear images. However, the establishment and adjustment of such an outdoor antenna are difficult. Therefore, a compact antenna, such as a ring-shape or telescopic antenna, has been developed for indoor use. Although this ring-shape or telescopic antenna is easy to use, the user may need to manually adjust the receiving angle and direction of the antenna. If a TV program of a different frequency band is desired, the adjustment of antenna must be repeated. Therefore, the use of ring-shape or telescopic antenna is still not satisfactory. Accordingly, there is a desire to have an improved antenna device to mitigate and/or obviate the aforementioned problems. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide an antenna device having a learning function and capable of searching and memorizing wireless frequency bands for automatically searching and adjusting the wireless TV band. 
     To achieve the object, the antenna device of the present invention comprises: a shell; a rotation set arranged in the shell; an antenna set formed on top of the shell and pivotally connected to the rotation set for adjusting its receiving angle by rotating the rotation set; a master controller; a motor connected to the rotation set and connected to an output terminal of the master controller via a driving circuit for being controlled by the master controller to drive the rotation set to rotate; a positioning detector connected between the rotation set and the master controller for detecting a current position of the antenna set, and inputting the detected signal to the master controller; a wireless receiving device connected to an input terminal of the master controller for receiving corresponding signals from a remote control and inputting the received signal to the master controller; a memory connected to the master controller for recording data related to a plurality of bands, wherein the master controller controls the rotation set to adjust the receiving angle of the antenna set by controlling the motor to rotate, and detects the position of the antenna set by the positioning detector for being inputted to the master controller, thereby searching and recording wireless bands. 
     Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the antenna device in accordance with the present invention; 
     FIG. 2 is a partially exploded view of the antenna device in accordance with the present invention; 
     FIG. 3 is a block diagram of the antenna device in accordance with the present invention; 
     FIGS. 4A and 4B show the circuit diagram of the antenna device in accordance with the present invention; and 
     FIG. 5 schematically illustrates the operation of the antenna device in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG.  1  and FIG. 2 illustrate the perspective view and the partially exploded view of the antenna device having a learning function and capable of searching and memorizing wireless frequency bands in accordance with a preferred embodiment of the present invention. As shown, the antenna device includes a shell  1 , a rotation set  25  having a pivot  252  and a gear set  251 , and an antenna set  11  formed on the top of the shell  1  and connected to the pivot  252  of the rotation set  25  for adjusting its receiving angle and direction by rotating the rotation set  25 . 
     Also with reference to FIG. 3, there is shown a block diagram of the control circuit for adjusting the rotation of the rotation set  25 , which includes a master controller  10 , a motor  17 , a positioning detector  13 , a memory  15 , a signal amplifying circuit  19 , a switching circuit  20 , a display device  23 , a key pad  14 , and a wireless receiving device  21 . 
     The motor  17  is connected to the rotation set  25 , and is connected to the output terminal of the master controller  10  via a driving circuit, so as to drive the rotation set  25  to rotate under the control of the master controller  10 . The positioning detector  13  is connected to the rotation set  25 , and is connected to the master controller  10  for detecting the angle and position of the antenna set  11 . The detected signal is sent to master controller  10 . In this embodiment, the positioning detector  13  is a potentiometer. 
     The memory  15  is connected to the master controller  10  for recording the data inputted from the positioning detector  13 . The signal amplifying circuit  19  is connected to the output terminal of the antenna set  11  for  20  amplifying the output signal from the antenna set  11 . 
     The switching circuit  20  is connected to the output terminal of the master controller  10 , and is connected between the signal amplifying circuit  19  and the cable TV signal terminal for switching either the wireless TV signal or the cable TV signal to a TV  24 . 
     The display device  23  is connected to the master controller  10  via the driving circuit  22  for being driven by the master controller  10  to display. The control key pad  14  is connected to the input terminal of the master controller  10 . 
     The wireless receiving device  21  is connected to the input terminal of the master controller  10  for receiving a signal from a remote control  3  as shown in FIG. 5, and the received signal is inputted to the master controller  10 . In this embodiment, the wireless receiving device  21  is an infrared receiving module (such a wireless remote control which is not restricted to a specific brand). 
     The aforementioned antenna device utilizes the master controller  10  to control the motor  17  in the rotation set  25  to rotate, and drive the gear set  251  to rotate. Furthermore, the pivot  252  is engaged with the gear set  251 , and thus the gear set  251  can activate the antenna set  11  to rotate, thereby adjusting the angle of the antenna set  11  and the adjustment value of the positioning detector  13 . 
     In use of the antenna device in accordance with the present invention, the antenna set  11  is fixed in a specific angle to receive clear video signals. Because the positioning detector  13  and the antenna set  11  are simultaneously activated by the rotation of the rotation set  25 , when the antenna set  11  is adjusted to have a specific angle, the resistance of the positioning detector  13  is changed to obtain a corresponding voltage signal for being inputted to the master controller  10 . The master controller  10  thus stores the voltage signal as a switched band number into the memory  15  for being associated with the current channel identification number. Afterwards, when a corresponding channel number is entered by the key pad  14  or the remote control, the master controller  10  directly controls the rotation set  25  to rotate, so as to move the antenna set  11  to have an angle capable of receiving signals represented by the band number. 
     With reference to FIGS. 4A and 4B, there is shown the detailed circuit diagram of the control circuit. As shown, the master controller  10  is a microprocessor (U 3 ), whose input terminals are connected to the positioning detector  13  (VR 2 ), the key pad  14  (N 1 ˜N 5 ), and infrared receiving module (U 5 ) for receiving the control signal inputted from the remote control (not shown). The microprocessor (U 3 ) has two output terminals (RA 2 , RC 0 ) connected to a motor driving circuit  16  formed by two sets of complementary transistors (Q 1 /Q 5 , Q 2 /Q 4 ), wherein the motor  17  is connected to the output terminal of the motor driving circuit  16 . If the two output terminals (RA 2 , RC 0 ) of the microprocessor (U 3 ) output high voltage levels at the same time, both of the two sets of complementary transistors (Q 1 /Q 5 , Q 2 /Q 4 ) are not conducted. If the output terminal (RA 2 ) outputs a high voltage level and the output terminal (RC 0 ) outputs a low voltage level, the transistor set (Q 2 /Q 4 ) is conducted and the motor  17  is rotated in a positive direction. On the contrary, if the output terminal (RA 2 ) outputs a low voltage level and the output terminal (RC 0 ) outputs a high voltage level, the transistor set (Q 1 /Q 5 ) is conducted and the motor  17  is rotated in a reverse direction. 
     In addition, the memory  15  is preferred to be an EEPROM, and the signal amplifying circuit  19  has three stages of amplifiers, each being composed of NPN transistors (Q 8 , Q 9 , Q 10 ) and resistors, so as to increase the overall amplifying gain of the signal amplifying circuit  19 . The output terminal of the previous stage and its working power are both connected to the switching circuit  20 . The switching circuit  20  is connected to the output terminal (RC 7 ) of the microprocessor (U 3 ), and is composed of transistors (Q 11 , Q 12 , Q 3 ). When the output terminal RC 7  outputs a high voltage level, the PNP transistor (Q 3 ) is not conducted and thus disconnects the working power supplied to the signal amplifying circuit  19 . At this moment, the two diodes (D 2 , D 3 ) connected to the signal terminal of cable TV are still conducted. Therefore, the cable TV signal (CATV IN) is directed to the output terminal (OUTPUT), so as to transmit the cable TV signal to the TV set. On the contrary, when the output terminal RC 7  outputs a low voltage level, the PNP transistor (Q 3 ) is conducted and thus the working power can be supplied to the signal amplifying circuit  19  so that the signals received by the antenna set  11  can be transmitted to the output terminal (OUTPUT) via the diode (D 1 ) for being sent to the TV set (not shown). 
     FIG. 5 is a schematic diagram illustrating the operation of the antenna device in accordance with the present invention. As shown, the antenna set  11  is moved in response to the rotation of the rotation set  25 . Therefore, when the master controller  10  controls the motor  17 , the receiving angle of the antenna set  11  can be adjusted, thereby achieving the purpose of searching and recording signals from various directions. 
     In view of the foregoing, as no default band is set in the master controller, the present invention is able to automatically set the optimal receiving band in the first-time use, and program a channel identification number. In addition, with the designs of various remote controls, it is easy for the user to operate the antenna device in accordance with the present invention. Therefore, the present antenna device not only can search and learn, but also can memorize the searched bands. 
     Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.