Abstract:
Methods and apparatuses are provided for remote-controlling a target apparatus using a mobile communication terminal. A communication link is established with the target apparatus having a display screen adapted to visualize an object. An amount of displacement of the mobile communication terminal is detected. Motion information is generated using the amount of displacement of the mobile communication terminal. The motion information is transmitted to the target apparatus. The motion information corresponds to movement data of the object and the amount of displacement is detected based on at least one of current position information, acceleration information and angular velocity information of the mobile communication terminal.

Description:
PRIORITY 
     This application is a Continuation Application of U.S. application Ser. No. 12/246,104, filed in the U.S. Patent and Trademark Office on Oct. 6, 2008, which claims priority under 35 U.S.C. §19(a) to a Korean Patent Application filed in the Korean Intellectual Property Office on Oct. 4, 2007 and assigned Ser. No. 10-2007-0100053, the disclosures of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a remote control method for remote-controlling a target apparatus using a mobile communication terminal, and a remote control system thereof. 
     2. Description of the Related Art 
     Recently, as the Liquid Crystal Display (LCD) equipped with electronics devices becomes bigger, the size of the monitor of a Personal Computer (PC) and the like also increases in size. In addition, it is possible to display hologram or lifelike broadcasting in a three-dimensional (3D) manner using the monitor of the PC. 
     Meanwhile, a technology has been developed that uses a mobile communication terminal as an input device, in place of a mouse which is an input device of the PC. A conventional mobile communication terminal which remote-controls the PC, merely performs an On/Off or Hot-key function of the PC, or moves a pointer displayed on a display screen using a 4-way key. Particularly, since the technology of controlling the PC using the mobile communication terminal has restrictions on the number of functions, it was difficult to fully control the PC without the mouse separately connected thereto. 
     SUMMARY OF THE INVENTION 
     An aspect of the present invention is to address at least the problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a remote control method for remote-controlling a target apparatus that displays a 3D display screen, using a mobile communication terminal, and a remote control system thereof. 
     According to an aspect of the present invention, a mobile communication terminal is provided that includes a motion sensor, and a transceiver configured for communication with a target apparatus including a display screen. The mobile communication terminal also includes a processing unit configured to establish, via the transceiver, a communication link with the target apparatus having the display screen adapted to visualize an object, detect an amount of displacement of the mobile communication terminal, via the motion sensor, generate motion information using the amount of displacement of the mobile communication terminal, and transmit the motion information to the target apparatus. The motion information corresponds to movement data of the object and the amount of displacement is detected based on at least one of current position information, acceleration information and angular velocity information of the mobile communication terminal. 
     According to another aspect of the present invention, a remote control method is provided for remote-controlling a target apparatus using a mobile communication terminal. A communication link is established with the target apparatus having a display screen adapted to visualize an object. An amount of displacement of the mobile communication terminal is detected. Motion information is generated using the amount of displacement of the mobile communication terminal. The motion information is transmitted to the target apparatus. The motion information corresponds to movement data of the object and the amount of displacement is detected based on at least one of current position information, acceleration information and angular velocity information of the mobile communication terminal. 
     According to another aspect of the present invention, a target apparatus is provided that is remote-controlled by a mobile communication terminal. The target apparatus includes a transceiver configured for communication with the mobile communication terminal. The target apparatus also includes a display to visualize an object. The target apparatus further includes a processing unit configured to establish, via the transceiver, a communication link with the mobile communication terminal, receive data corresponding to an amount of displacement of the mobile communication terminal, generate motion information using the amount of displacement of the mobile communication terminal, and move the object according to the motion information. The motion information corresponds to movement data of the object, and the amount of displacement is detected based on at least one of current position information, acceleration information and angular velocity information of the mobile communication terminal. 
     According to another aspect of the present invention, a remote control method is provided for remote-controlling a target apparatus using a mobile communication terminal. A communication link is established with the mobile communication terminal. Data is received corresponding to an amount of displacement of the mobile communication terminal. Motion information generated using the amount of displacement of the mobile communication terminal is generated. An object displayed on a display of the target apparatus is moved according to the motion information. The motion information corresponds to movement data of the object, and the amount of displacement is detected based on at least one of current position information, acceleration information and angular velocity information of the mobile communication terminal 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other aspects, features and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings in which: 
         FIG. 1  is a block diagram illustrating a schematic structure of a remote control system according to an embodiment of the present invention; 
         FIG. 2  is a diagram illustrating a mobile communication terminal according to an embodiment of the present invention; 
         FIG. 3  is a flowchart illustrating a method for determining a reference point between a mobile communication terminal and a PC in a remote control system according to an embodiment of the present invention; 
         FIG. 4  is a diagram illustrating a mobile communication terminal and a PC, for determining reference point coordinates in a remote control system according to an embodiment of the present invention; 
         FIG. 5  is a flowchart illustrating a method in which a mobile communication terminal remote-controls a PC in a remote control system according to an embodiment of the present invention; 
         FIG. 6  is a flowchart illustrating a method in which a mobile communication terminal remote-controls a PC in a remote control system according to an embodiment of the present invention; 
         FIGS. 7A and 7B  are diagrams illustrating shifting of a pointer of a PC in a remote control system according to an embodiment of the present invention; 
         FIGS. 8A and 8B  are diagrams illustrating games realized in a remote control system according to an embodiment of the present invention; and 
         FIG. 9  is a flowchart illustrating a method in which a mobile communication terminal remote-controls a PC in a remote control system according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Preferred embodiments of the present invention will now be described in detail with reference to the annexed drawings. In the drawings, the same or similar elements are denoted by the same reference numerals even though they may be depicted in different drawings. In the following description, a detailed description of known functions and configurations incorporated herein has been omitted for clarity and conciseness. 
     In the following description, the target apparatus is assumed to be a Personal Computer (PC). However, the target apparatus may include any device having a two-dimensional (2D) or three-dimensional (3D) display screen, as well as a PC. 
       FIG. 1  is a block diagram illustrating a schematic structure of a remote control system according to a preferred embodiment of the present invention. 
     The remote control system includes a mobile communication terminal  10  and a PC  40 , and the mobile communication terminal  10  and the PC  40  are wire/wireless-connected to each other to exchange data. 
     The mobile communication terminal  10  includes a Radio Frequency (RF) unit (not shown), a transceiver  12 , a key input unit  14 , a first display  16 , a first memory  18 , a motion information generator  20 , and a first controller  30 . 
     The RF unit performs a wireless communication function of the mobile communication terminal  10 . The RF unit includes an RF transmitter (not shown) for frequency up-converting and amplifying a transmission signal, and an RF receiver (not shown) for low-noise-amplifying and frequency down-converting a received signal. 
     The transceiver  12  transmits a signal generated in a signal generator  22  to the PC  40 , and receives a radio signal generated in the PC  40 . The transceiver  12  transmits, to the PC  40 , an initialization signal, a motion signal, and pointer motion information, generated in the signal generator  22 . The transceiver  12  receives an initialization response signal and a motion response signal, generated in the PC  40 . 
     The key input unit  14  includes alphanumeric keys capable of receiving numerals, characters and function keys for setting various functions, and receives inputs from a user. 
     According to a preferred embodiment of the present invention, the key input unit  14  can receive from the user a key input for carrying out a remote control mode of the mobile communication terminal  10 . In the remote control mode, the key input unit  14  can receive a key input for performing an operation corresponding to a position pointed by a pointer of the PC  40 . A Hot-key function can be set in the key input unit  14 . In this case, if a numeric/character key input is received through the key input unit  14 , a particular function of the PC  40 , which is set in the corresponding numeric/character key, can be immediately performed. 
     The first display  16 , which can be an LCD, outputs various display data generated by the mobile communication terminal  10 . When the LCD is a touch screen, the first display  16  can also serve as an input means. 
     The first memory  18  can be composed of a program memory and a data memory. Various information necessary for controlling an operation of the mobile communication terminal  10  is stored in the first memory  18 . 
     According to a preferred embodiment of the present invention, data is generated and stored in the first memory  18  when the mobile communication terminal  10  executes the remote control mode, such as: (i) reference point coordinates of the PC  40 , (ii) a position value of the mobile communication terminal  10  corresponding to the reference point coordinates, (iii) display information of the PC  40 , (iv) an angular velocity of the mobile communication terminal  10  calculated by a gyro sensor, (v) an acceleration of the mobile communication terminal  10  calculated by an acceleration sensor, (vi) a current position value of the mobile communication terminal  10  calculated by a position sensor, and (vii) motion point coordinates of the PC  40  corresponding to the current position value. 
     The motion information generator  20  generates motion information, which is information indicating how the pointer of the PC  40  will move on the display screen of the PC  40  in response to movement of the mobile communication terminal  10 . For this, the motion information generator  20  includes the signal generator  22  and a pointer motion information generator  24 . 
     The signal generator  22  generates the signals necessary when the mobile communication terminal  10  carries out the remote control mode. When the mobile communication terminal  10  executes the remote control mode by the controller  30  or upon receipt of a user input, the signal generator  22  generates an initialization signal to set reference point coordinates of the PC  40 . The term “reference point coordinates” refers to coordinates of the point where a communication interface  42  of the PC  40  has received the initialization signal. The signal generator  22  generates an initialization signal that includes data indicating the execution of the remote control mode, and data for requesting coordinates of the reference point which is a point where the initialization signal has arrived. 
     According to a preferred embodiment of the present invention, if the position of the mobile communication terminal  10  is changed by the user while executing the remote control mode, the signal generator  22  generates a motion signal for moving the pointer of the PC  40  according to the movement of the mobile communication terminal  10 . The signal generator  22  generates the motion signal that includes (i) data for requesting coordinates of the motion point which is the point where the initialization signal has arrived at the PC  40 , (ii) a current position value based on the movement of the mobile communication terminal  10 , and (iii) acceleration and angular velocity of the mobile communication terminal  10  obtained when it moves from the previous position to the current position. 
     In addition, according to another preferred embodiment of the present invention, the signal generator  22  can generate a periodic signal. As the signal generator  22  generates the periodic signal, the first controller  30  can measure the time required when the initialization signal or the motion signal, transmitted from the signal generator  22  to the PC  40 , comes back to the mobile communication terminal  10  after being processed into an initialization response signal or a motion response signal by the PC  40 . The first controller  30  measures a round-trip time of the initialization signal, and stores it in the first memory  18 . Thereafter, the first controller  30  measures a round-trip time of the motion signal based on the movement of the mobile communication terminal  10 , and compares it with the round-trip time of the initialization signal. As a result, the first controller  30  can determine if the distance from the PC  40  is shorter or longer than as compared with when the mobile communication terminal  10 , which has generated the motion signal, transmitted the initialization signal. 
     The pointer motion information generator  24  generates pointer motion information which is the information for moving the pointer of the PC  40  according to the movement of the mobile communication terminal  10 . The pointer motion information generator  24 , under the control of the controller  30 , calculates distance, velocity and angle at which the pointer of the PC  40  should move on the display screen of the PC  40  according to the movement of the mobile communication terminal  10 . 
     According to the present invention, the motion information generator  20 , which includes an acceleration sensor, a gyro sensor and a position sensor, can sense acceleration, angular velocity, and position of the mobile communication terminal  10  due to the movement of the mobile communication terminal  10  by the user. The acceleration sensor is a sensor for measuring an acceleration of an object by sensing dynamic power of acceleration, vibration, impact, etc. The gyro sensor is a sensor for sensing an angular velocity that acts in the inertial system. The position sensor, which can be, for example, a Global Positioning System (GPS), senses a correct position every time the mobile communication terminal  10  moves by the user. 
     The first controller  30  controls the overall operation of the mobile communication terminal  10 . According to a preferred embodiment of the present invention, when a user input for the remote control mode is received through the key input unit  14 , the first controller  30  switches the mode of the mobile communication terminal  10  to the remote control mode. In addition, when a user input for switching from the remote control mode to another operation mode is received through the key input unit  14  during the remote control mode, the first controller  30  switches to the other operation mode after ending the remote control mode. 
     When the remote control mode is executed, the first controller  30  transmits an initialization signal to the PC  40 , receives an initialization response signal therefrom, and controls the motion information generator  20  to calculate a distance between the mobile communication terminal  10  and the PC  40 . The first controller  30  stores reference point coordinates received from the PC  40  in the first memory  18 . 
     When movement by the user is sensed, the first controller  30  controls the motion information generator  20  to generate a motion signal according to the movement. When a motion response signal is received from the PC  40  in response to the motion signal, the first controller  30  stores the motion point coordinates included in the motion response signal in the first memory  18 . 
     The first controller  30  controls the pointer motion information generator  24  to generate pointer motion information using the motion point coordinates included in the motion response signal. 
     The PC  40  in the remote control system includes the communication interface  42 , a second memory  44 , a second display  46 , a coordinate determiner  48 , and a second controller  50 . 
     The communication interface  42  performs a wire/wireless communication function of the PC  40 . According to a preferred embodiment of the present invention, the communication interface  42  receives the initialization signal, motion signal and pointer motion information, transmitted from the mobile communication terminal  10 , and transmits to the mobile communication terminal  10  the initialization response signal and motion response signal generated in the coordinate determiner  48  of the PC  40 . 
     According to a preferred embodiment of the present invention, the communication interface  42  can be, for example, a display screen. When the communication interface  42  is a display screen, the initialization signal or motion signal transmitted from the mobile communication terminal  10  is received at a certain point on the display screen, converted into an initialization response signal or a motion response signal, and then transmitted back to the mobile communication terminal  10 . 
     The second memory  44 , like the first memory  18 , can be composed of a program memory and a data memory. Various information necessary for controlling an operation of the PC  40  is stored in the second memory  44 . 
     According to a preferred embodiment of the present invention, the second memory  44  receives an initialization signal from the mobile communication terminal  10 , and stores the current position value of the mobile communication terminal  10  based on the initialization signal, and coordinates of a reference point which is the point where the initialization signal has arrived at the PC  40 . When the PC  40  receives a motion signal, the second memory  44  stores the current position value, acceleration and angular velocity of the mobile communication terminal  10  based on the motion signal. When coordinates of the motion point are determined by the coordinate determiner  48 , the second memory  44  stores the determined motion point coordinates. 
     In addition, the second memory  44  can store pointer motion information transmitted from the mobile communication terminal  10 . The pointer motion information includes motion point coordinates, moving distance, and moving velocity of the pointer, which are the information needed for moving the pointer of PC  40  on the display screen. 
     Like the first display  16 , the second display  46 , which can be composed of an LCD, outputs various display data generated in the PC  40 . When the LCD is a touch screen, the second display  46  can also serve as an input means. 
     According to a preferred embodiment of the present invention, when the mobile communication terminal  10  executes the remote control mode, the second display  46  moves the displayed pointer according to the pointer motion information received from the mobile communication terminal  10 . The second display  46  can serve as the communication interface  42  that receives the initialization signal and the motion signal. When the second display  46  serves as the communication interface  42 , coordinates of the point where the initialization signal or motion signal received from the mobile communication terminal  10  has arrived, become reference point coordinates or motion point coordinates corresponding to the current position value of the mobile communication terminal  10 . 
     The coordinate determiner  48 , under the control of the second controller  50 , generates an initialization response signal and a motion response signal corresponding to the initialization signal and the motion signal received from the mobile communication terminal  10 . Further, the coordinate determiner  48  determines coordinates of a reference point which is the point where the initialization signal is received, and coordinates of a motion point which is the point where the motion signal is received. 
     When the initialization signal is received, the coordinate determiner  48  determines a reference point corresponding thereto, and generates an initialization response signal including coordinates of the reference point. Since the reference point is a point based on which the pointer of the PC  40  is later displayed according to the movement of the mobile communication terminal  10 , the coordinate determiner  48  can determine the coordinates as, for example, (0, 0, 0) corresponding to the coordinates of the reference point on the X, Y and Z axes of a 3D coordinate system, respectively. The coordinate determiner  48  can generate an initialization response signal including display information of the PC  40 . The display information is information on the display device of the PC  40  such as resolution information of the PC  40 . 
     When a motion signal is received from the mobile communication terminal  10 , the coordinate determiner  48  determines coordinates of the motion point which is the point where the motion signal is received. The coordinate determiner  48  generates a motion response signal including the motion point coordinates, and transmits the motion response signal to the mobile communication terminal  10 . According to another preferred embodiment of the present invention, the coordinate determiner  48  can calculate a distance from the reference point to the motion point. The coordinate determiner  48  then generates a motion response signal including the distance from the reference point to the motion point. 
     The second controller  50  controls the overall operation of the PC  40 . According to a preferred embodiment of the present invention, when an initialization signal is received from the mobile communication terminal  10 , the second controller  50  perceives that the mobile communication terminal  10  executes the remote control mode. When the initialization signal is received, the second controller  50  controls the coordinate determiner  48  to determine reference point coordinates for the initialization signal, and when the motion signal is received, the second controller  50  controls the coordinate determiner  48  to determine the motion point coordinates for the motion signal. 
     When the pointer motion information is received from the mobile communication terminal  10 , the second controller  50  controls the second display  46  to display the pointer according to the received pointer motion information. 
       FIG. 2  is a diagram illustrating a mobile communication terminal according to a preferred embodiment of the present invention. 
     As shown in  FIG. 2 , the mobile communication terminal  10  has three axes: an X axis, a Y axis, and a Z axis. Accordingly, the mobile communication terminal  10  can receive an input not only from the 2D X/Y-axis plane but also from the 3D screen. Referring to  FIG. 2 , when the mobile communication terminal  10  moves along the X axis, the pointer of the PC  40  moves left and right on the display screen. When the mobile communication terminal  10  moves along the Y axis, the pointer of the PC  40  moves up and down on the display screen. When the mobile communication terminal  10  moves along the Z axis, the pointer of the PC  40  moves in and out to/from the display screen, with the distance between the mobile communication terminal  10  and the PC  40  getting shorter and longer. 
       FIG. 3  is a flowchart illustrating a method for determining a reference point between a mobile communication terminal and a PC in a remote control system according to a preferred embodiment of the present invention. 
     The key input unit  14  of the mobile communication terminal  10  receives a key input for execution of the remote control mode from the user, and the controller  30  executes remote control mode in Step S 62 . The controller  30  controls the pointer motion information generator  24  of the motion information generator  20  to calculate a current position value of the mobile communication terminal  10  in Step S 64 . 
     The current position value of the mobile communication terminal  10 , calculated in Step S 64 , is a value based on which the position value of the mobile communication terminal  10  can be determined when the mobile communication terminal  10  is moved by the user after initialization for execution of the remote control mode. Therefore, if it is assumed in Step S 64  that the current position value of the mobile communication terminal  10  is indicated by X/Y/Z-axis 3D coordinates, it is preferable that the current position value is designated as the origin of (0, 0, 0). In this case, it is assumed that the X axis, the Y axis and the Z axis in the mobile communication terminal  10  are different from the X axis, the Y axis and the Z axis in the PC  40 . 
     The signal generator  22  generates an initialization signal in Step S 66 . The initialization signal is a signal generated to determine particular coordinates on the display screen of the PC  40 , which correspond to the current position value calculated in Step S 64 , in order to map each position to which mobile communication terminal  10  moves, to the position on the display screen of the PC  40 . 
     The PC  40  receives the initialization signal from the mobile communication terminal  10  in Step S 68 , and determines reference point coordinates corresponding to the current position value in Step S 70 . The initialization signal transmitted from the mobile communication terminal  10  is received at the PC  40  in such a manner that it arrives at a certain point on the display screen, and the PC  40  determines the point where the initialization signal has arrived, as a reference point, and transmits the coordinates to the mobile communication terminal  10 . In this case, the reference point coordinates can be, for example, any one of the multiple pixels distributed on the display screen of the PC  40 . 
     According to a preferred embodiment of the present invention, the PC  40  can determine coordinates of the point where the initialization signal of the mobile communication terminal  10  is received as (0, 0, 0), and recalculate coordinates for each point where the pointer is located, using the reference point. 
     The PC  40  transmits an initialization response signal including the reference point coordinates to the mobile communication terminal  10  in Step S 72 . According to a preferred embodiment of the present invention, the PC  40  transmits the initialization response signal including the display information. The display information can include screen resolution of the PC  40 , and driver information for the display device of the PC  40 . 
     The mobile communication terminal  10  receives the initialization response signal from the PC  40  in Step S 72 . The mobile communication terminal  10  calculates the distance from the PC  40 , and stores reference point coordinates in Step S 74 . 
     The pointer motion information generator  24 , under the control of the first controller  30 , measures the time from the transmission time of the initialization signal to the reception time of the initialization response signal, and calculates the distance between the mobile communication terminal  10  and the PC  40  using the measured time. 
     When the initialization signal generated in the signal generator  22  arrives at the PC  40 , it is processed into an initialization response signal and then transmitted back to the mobile communication terminal  10 . The time for which the initialization signal is processed into the initialization response signal is negligibly shorter than the time for which the initialization signal or the initialization response signal is delivered. According to a preferred embodiment of the present invention, the time for which the initialization signal arrives at the PC  40  from the mobile communication terminal  10  is equal to the time for which the initialization response signal arrives at the mobile communication terminal  10  from the PC  40 . Therefore, the time for which the initialization signal is transmitted to the PC  40  and then its associated initialization response signal is received at the mobile communication terminal  10 , can be regarded as the round-trip time between the mobile communication terminal  10  and the PC  40  for the initialization signal. 
     Since the pointer motion information generator  24  knows the time required when the initialization signal makes a round trip between the mobile communication terminal  10  and the PC  40 , it can find the distance between the mobile communication terminal  10  and the PC  40 . Here, a velocity of the initialization signal is previously stored in the first memory  18 , and the initialization signal can be, for example, infrared rays and ultrasonic waves. 
       FIG. 4  is a diagram illustrating a mobile communication terminal and a PC, for determining reference point coordinates in a remote control system according to a preferred embodiment of the present invention. 
     In the drawing, the mobile communication terminal  10  and the PC  40  both use the X/Y/Z-axis 3D coordinate system. 
     The mobile communication terminal  10  transmits an initialization signal, and the PC  40  receives the initialization signal. The PC  40  determines the point where the initialization signal is received, as a reference point, and then determines the coordinates of the reference point. Preferably, the coordinate determiner  48  determines the reference point coordinates as (0, 0, 0). The mobile communication terminal  10  then receives an initialization response signal including the reference point coordinates, transmitted from the PC  40 . Preferably, the mobile communication terminal  10  receives the initialization response signal in the position where it transmitted the initialization signal. 
     Shown in  FIG. 4  is a diagram for the case when the communication interface  42  of the PC  40  that received the initialization signal from the mobile communication terminal  10  is a display screen. Therefore, the coordinate determiner  48  determines the point where the initialization signal has arrived on the display screen of the PC  40  as a reference point, and transmits coordinates of the determined reference point to the mobile communication terminal  10 . 
     The mobile communication terminal  10  receives the initialization response signal transmitted from the PC  40  in the position where it transmitted the initialization signal, and measures the time for which the initialization signal is transmitted from the mobile communication terminal  10  to the PC  40 , and the time for which the initialization response signal is transmitted from the PC  40  to the mobile communication terminal  10 . The mobile communication terminal  10  then calculates the distance between the mobile communication terminal  10  and the PC  40  using the measured time, and stores it in the first memory  18 . 
     The distance between the mobile communication terminal  10  and the PC  40  in the process of determining a reference point using the initialization signal becomes an origin point based on which the first controller  30  can later determine whether the mobile communication terminal  10  has become closer to or further away from the PC  40  when the mobile communication terminal  10  is moved by the user. The distance between the mobile communication terminal  10  and the PC  40  in the process of determining the reference point coordinates using the initialization signal will be referred to herein as a “reference distance”. 
     According to the present invention, when the distance between the mobile communication terminal  10  and the PC  40  is further than the reference distance, the mobile communication terminal  10  generates pointer motion information that displays the pointer of the PC  40  as if it moves in the opposite direction (e.g., +Z axis) of the direction of the mobile communication terminal  10 . On the contrary, when the distance between the mobile communication terminal  10  and the PC  40  is closer than the reference distance, the mobile communication terminal  10  generates pointer motion information that displays the pointer of the PC  40  as if it moves toward the direction (e.g., −Z axis) of the position where the mobile communication terminal  10  is located. 
       FIG. 5  is a flowchart illustrating a method in which a mobile communication terminal remote-controls a PC in a remote control system according to a preferred embodiment of the present invention. 
     It is assumed in  FIG. 5  that the mobile communication terminal  10  is now executing the remote control mode, and reference point coordinates of the PC  40  and a position value of the mobile communication terminal  10 , which corresponds to the reference point coordinates, are previously stored in the first memory  18  and the second memory  44 . 
     The first controller  30  senses a movement of the mobile communication terminal  10  in Step S 82 . The movement of the mobile communication terminal  10  indicates a change in position of the mobile communication terminal  10  from a first position to a second position by the user, or a change in the angle of the mobile communication terminal  10  with respect to the PC  40  from a first angle to a second angle. In the remote control mode, the movement of the mobile communication terminal  10  is sensed through at least one of a position sensor, an acceleration sensor and a gyro sensor. 
     The signal generator  22  generates a motion signal under the control of the first controller  30  in Step S 84 . The motion signal is a signal generated to move the pointer of the PC  40  according to the movement of the mobile communication terminal  10 . The signal generator  22  can generate a motion signal including the acceleration, the angular velocity and the current position value of the mobile communication terminal  10 . 
     The mobile communication terminal  10  transmits the generated motion signal to the PC  40  in Step S 86 . The PC  40  receives the motion signal, and generates its associated motion response signal in Step S 88 . The coordinate determiner  48  of the PC  40  can generate a motion response signal including pointer motion point coordinates. 
     The PC  40  transmits the motion response signal to the mobile communication terminal  10  in Step S 90 , and the mobile communication terminal  10  receives the motion response signal and generates pointer motion information depending thereon in Step S 92 . The pointer motion information is information indicating how the pointer of the PC  40  should move in reply to the movement of the mobile communication terminal  10 . The PC  40  receives pointer motion information from the mobile communication terminal  10  in Step S 94 , and moves the displayed pointer according to the received pointer motion information in Step S 96 . 
       FIG. 6  is a flowchart illustrating a method in which a mobile communication terminal remote-controls a PC in a remote control system according to a preferred embodiment of the present invention. 
     The mobile communication terminal  10  senses a movement for shifting a pointer of the PC  40  in Step S 102 . Using the sensors, the mobile communication terminal  10  calculates a its current position value, and the acceleration and the angular velocity obtained when it moves from the previous position to the current position in Step S 104 . The first controller  30  controls the position sensor to sense the current position of the mobile communication terminal  10 , and senses a moving velocity and an acceleration based on the moving velocity when the mobile communication terminal  10  moves from the previous position to the current position, using the acceleration sensor. Using the gyro sensor, the first controller  30  can sense whether a body of the mobile communication terminal  10  is inclined as compared with the previous position. 
     The signal generator  22  generates a motion signal including the current position value, the acceleration and the angular velocity of the mobile communication terminal  10 , and the first controller  30  transmits the generated motion signal to the PC  40  via the transceiver  12  in Step S 106 . 
     Upon receipt of the motion signal from the mobile communication terminal  10 , the PC  40  determines pointer motion point coordinates according to the current position value of the mobile communication terminal  10 , and generates a motion response signal including the pointer motion point coordinates. The PC  40  transmits the generated motion response signal to the mobile communication terminal  10  through the communication interface  42 . 
     The transceiver  12  in the mobile communication terminal  10  receives from the PC  40  the motion response signal including the motion point coordinates of the pointer, which correspond to the current position value in Step S 108 . 
     The pointer motion information generator  24  calculates a distance from the PC  40  by measuring the time from the transmission time of the motion signal to the reception time of the motion response signal in Step S 110 . By calculating the distance from the PC  40 , the mobile communication terminal  10  can determine if the distance from the PC  40  in its current position is longer or shorter than the distance from the PC  40  in its previous position. In addition, if the time from the transmission time of the motion signal to the reception time of the motion response signal in the current position is equal to that in the previous position, it is obvious that the distance between the mobile communication terminal  10  and the PC  40  is not changed. 
     The pointer motion information generator  24  generates pointer motion information using acceleration, angular velocity, motion point coordinates of the pointer, and distance from the PC  40  in Step S 112 . The pointer motion information generator  24  determines a velocity of the mobile communication terminal  10  using the acceleration of the mobile communication terminal  10  when the pointer of the PC  40  has moved. In addition, the pointer motion information generator  24  determines an angle of the mobile communication terminal  10  using the angular velocity when the pointer moves on the display screen. Using the distance from the PC  40 , the pointer motion information generator  24  determines whether it will shift the pointer forward or backward on the display screen when the pointer has moved to the motion point coordinates corresponding to the current position value from the motion point coordinates corresponding to the previous position value of the mobile communication terminal  10 . For example, when the distance between the mobile communication terminal  10  and the PC  40  becomes shorter, the pointer motion information generator  24  determines to display the motion point as if it moves back on the display screen; and when the distance between the mobile communication terminal  10  and the PC  40  becomes longer, the pointer motion information generator  24  determines to display the pointer as if it pops out. 
     The mobile communication terminal  10  transmits the pointer motion information to the PC  40  in Step S 114 . Upon receipt of the pointer motion information, the PC  40  can determine how it will move the displayed pointer according to the movement of the mobile communication terminal  10 . The PC  40  controls the second display  46  to display the pointer according to the pointer motion signal. 
     According to another preferred embodiment of the present invention, the PC  40  can generate in Step S 106  the pointer motion information using the current position value, the acceleration and the angular velocity received from the mobile communication terminal  10  and the motion point coordinates determined according to the current position value. 
       FIGS. 7A and 7B  are diagrams illustrating shifting of a pointer of a PC in a remote control system according to a preferred embodiment of the present invention. 
       FIG. 7A  illustrates pointer shifting when the PC  40  has a 2D display screen, and  FIG. 7B  illustrates pointer shifting when the PC  40  has a 3D display screen. 
     It is assumed in  FIG. 7A  that an angle of the mobile communication terminal  10  is 0° when coordinates of the point where the motion signal transmitted from the mobile communication terminal  10  has arrived at the PC  40  are (x 0 , y 0 , z 0 ), and an angle of the mobile communication terminal  10  is A° when coordinates of the point where the motion signal has arrived are (x 1 , y 1 , z 1 ). 
     Even though only the angle of the mobile communication terminal  10  is changed, the remote control system according to the present invention considers that the mobile communication terminal  10  has moved. Therefore, in  FIG. 7A , the PC  40  shifts the displayed pointer according to the movement of the mobile communication terminal  10 , considering that the mobile communication terminal  10  has been moved by the user. 
     The distance between the mobile communication terminal  10  and the PC  40  for the angle 0° is different from the distance between the mobile communication terminal  10  and the PC  40  for the angle A°. Since the mobile communication terminal  10  is inclined by A°, its distance from the PC  40  gets longer as compared with when the mobile communication terminal  10  is inclined by 0°. Therefore, although not shown in  FIG. 7A , the PC  40  should incline the displayed pointer toward the +Z axis. Since the PC  40  has a 2D display screen, the PC  40  displays the pointer as if it pops out toward the mobile communication terminal  10  at the point where it is inclined by A° toward the +Z axis at the coordinates of (x 0 , y 0 , z 0 ). In this manner, the coordinates of the pointer, which are calculated as the mobile communication terminal  10  moves, are (x 1 , y 1 , z 1 ). 
     Likewise, it is also assumed in  FIG. 7B  that an angle of the mobile communication terminal  10  is 0° when coordinates of the point where the motion signal transmitted from the mobile communication terminal  10  has arrived at the PC  40  are (x 0 , y 0 , z 0 ), and an angle of the mobile communication terminal  10  is B° when coordinates of the point where the motion signal has arrived are (x 2 , y 2 , z 2 ). 
     Even in  FIG. 7B , since the acceleration, the angular velocity and the current position value are changed as the angle of the mobile communication terminal  10  is inclined by B°, the PC  40  shifts the displayed pointer according thereto. Since the PC  40  has a 3D display screen, the pointer having coordinates of (x 2 , y 2 , z 2 ) is displayed at the point where it is inclined by B° toward the +Z axis with respect to the pointer having coordinates of (x 0 , y 0 , z 0 ). 
       FIGS. 8A and 8B  are diagrams illustrating games realized in a remote control system according to a preferred embodiment of the present invention. 
       FIG. 8A  illustrates a display screen of the PC  40 , on which a 3D game is played, and  FIG. 8B  illustrates a display screen of the PC  40 , on which a 2D game is played. 
     Referring to  FIGS. 8A and 8B , the user can shift the pointer of the PC  40  to his/her desired position by applying a motion to the mobile communication terminal  10 . The user not only can shift the pointer to the desired position, but also adjust a moving velocity of the pointer, while viewing the 3D display screen of  FIG. 8A  or the 2D display screen of  FIG. 8B . The user can move the mobile communication terminal  10  fast or slow, so the pointer can shift at the velocity corresponding thereto. 
     According to a preferred embodiment of the present invention, a predetermined command for the corresponding point where the pointer is positioned can be sent from the PC  40  to the mobile communication terminal  10  to be executed in the mobile communication terminal  10 . For example, when the pointer of the PC  40  arrives at a predetermined point, the mobile communication terminal  10  can generate a vibration, or the voice data stored in the first memory  18  can be played back. 
       FIG. 9  is a flowchart illustrating a method in which a mobile communication terminal remote-controls a PC in a remote control system according to a preferred embodiment of the present invention. 
     The first controller  30  of the mobile communication terminal  10  executes the remote control mode in Step S 122 , and receives a user input through the key input unit  14  in Step S 124 . 
     The first controller  30  determines if the user input received in Step S 124  is for shifting the pointer of the PC  40  in Step S 126 . If the user input is for shifting the pointer of the PC  40 , the first controller  30  controls the mobile communication terminal  10  to generate pointer motion information for the user input and to transmit it to the PC  40  in Step S 128 . 
     However, if the user input is not for shifting the pointer of the PC  40 , the first controller  30  performs an operation corresponding to the user input in Step S 130 . The operation can include performing an operation corresponding to the point where the pointer is positioned on the display screen of the PC  40 . According to a preferred embodiment of the present invention, the first controller  30  can control the signal generator  22  to generate a command for performing an operation corresponding to the point where the pointer is positioned, and send the generated command to the PC  40 . 
     As is apparent from the foregoing description, the present invention provides a remote control method for remote-controlling a target apparatus that displays a 3D display screen, using a mobile communication terminal, and a remote control system thereof. 
     While the invention has been shown and described with reference to a certain preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.