WO2009069896A1

WO2009069896A1 - Pointing module, method for calibrating zero point of the same, and electronic device having the same

Info

Publication number: WO2009069896A1
Application number: PCT/KR2008/006406
Authority: WO
Inventors: Sang Gweon Chang; Seung Hwan Lee
Original assignee: Innochips Technology Co., Ltd.
Priority date: 2007-11-28
Filing date: 2008-10-30
Publication date: 2009-06-04
Also published as: KR100892886B1; TW200925939A

Abstract

There is provided a method for calibrating a zero point of a pointing module, which includes determining whether or not a reference coordinate calibration command is provided from the outside; calibrating a sensing signal outputted from a pointing module as a reference coordinate (i.e., zero point); and storing the calibrated reference coordinate in a memory. While a pointing module does not operate, a reference coordinate is renewed, so that when the position of a magnet unit in the pointing module is changed, the automatically changed position of the magnet unit can be calibrated as a reference coordinate. In addition, before an electronic device is launched, reference coordinate information is stored in a memory, so that the present invention makes it possible to prevent the reference coordinate information from being changed to an undesired value.

Description

POINTING MODULE, METHOD FOR CALIBRATING ZERO POINT OF THE SAME, AND ELECTRONIC DEVICE HAVING

THE SAME

Technical Field

[1] The present invention relates to a pointing module, a method for calibrating a zero point of the same, and an electronic device having the same, and more particularly, to auto calibration of a pointing module mounted in an electronic device to control movement of a pointer on a display. Background Art

[2] Recently, electronic devices are designed to have smaller size and to be easily operated by using a graphic user interface (GUI) method. A variety of pointing devices, such as a mouse and a touch pad, are used to control a pointer of a graphic user interface.

[3] A hall mouse has been developed as one of these pointing devices. The hall mouse detects two-dimensional movements of a magnet by using sensors that sense a moving direction and intensity of the magnet, and controls a pointer on a screen. However, in order to apply the hall mouse to electronic devices, it is important to calibrate an initial reference coordinate value (i.e., zero point). That is, the moment an electronic device is turned on, a hall mouse should calibrate an initial reference coordinate value. However, if a magnet unit of the hall mouse is moved by a user or external force, an exact reference coordinate value cannot be calibrated. Disclosure of Invention Technical Problem

[4] Accordingly, the present invention is to provide a pointing module, a method for calibrating zero point of the same, and an electronic device having the same, wherein initial reference coordinate information of the pointing module is stored in a controller, so that a reference coordinate (i.e., zero point) of the pointing module can be automatically calibrated by using the stored information when the electronic device is booted. Technical Solution

[5] The present invention provides a method for calibrating a zero point of a pointing module, which includes the steps of determining whether or not a reference coordinate calibration command is provided from an outside; calibrating a sensing signal outputted from a sensor as a reference coordinate (i.e., zero point); and storing the calibrated reference coordinate in a storage unit.

[6] Further, the present invention provides a method for calibrating a zero point of a pointing module, which includes the steps of determining whether or not a position of an operating member is changed; receiving a sensing signal from a sensor to calibrate a new reference coordinate when the position of the operating member is not changed; and renewing an initial reference coordinate of a storage unit as the new reference coordinate.

[7] The determination of the change of the position of the operating member may be performed using whether or not the sensing signal is changed, it may be determined that the position of the operating member is not changed when the sensing signal has the same signal value for a position change sensing period, and it may be determined that the position of the operating member is changed when the sensing signal has a changed signal value for the position change sensing period.

[8] Furthermore, the present invention provides a method for calibrating a zero point of a pointing module, which includes the steps of assembling a pointing module; booting the pointing module; calibrating a sensing signal outputted from a sensor of the pointing module as a reference coordinate (i.e., zero point); and storing the calibrated reference coordinate in a storage unit.

[9] The step of calibrating a sensing signal as a reference coordinate preferably includes the steps of receiving a plurality of sensing signals for a sensing period to generate reference coordinates of the respective sensing signals; and calculating an average of the reference coordinates and calibrating the average as the reference coordinate.

[10] Moreover, the present invention provides a pointing module, which includes a sensor for sensing a movement of an operating member and outputting the sensed movement as a sensing signal; a reference coordinate generator for generating reference coordinate information using the sensing signal; a storage unit for storing the reference coordinate information therein; and a controller for controlling operation of the reference coordinate generator and the storage unit, and outputting the sensing signal and the reference coordinate information.

[11] The reference coordinate generator preferably generates the new reference coordinate information when the position of the operating member is not changed for a predetermined position change sensing period.

[12] The reference coordinate generator effectively generates the reference coordinate information in accordance with a control signal of the controller.

[13] The storage unit may include any one of EPROM, EEPROM and a flash memory.

[14] In addition, the present invention provides an electronic device, which includes an image display unit for displaying an image and a cursor; a pointing module for sensing a movement of an operating member to output the sensed movement as a sensing signal, generating reference coordinate information using the sensing signal, and storing the reference coordinate information; an information processing unit including an image signal generation module for controlling the image based on external image information, a cursor coordinate generation module for calculating a movement coordinate of the cursor using the sensing signal and the reference coordinate information to allow the cursor to be moved to the movement coordinate, and a control module for controlling operation of the image signal generation module, a memory, and the cursor coordinate generation module; and a power supply for supplying power to the pointing module, the image display unit and the information processing unit.

[15] The reference coordinate information is effectively stored in a storage unit before the electronic device is launched.

Advantageous Effects

[16] As described above, before an electronic device is launched, reference coordinate information is stored in a memory, so that the present invention makes it possible to prevent the reference coordinate information from being changed to an undesired value.

[17] Further, according to the present invention, while a pointing module does not operate, a reference coordinate is renewed, so that when the position of a magnet unit in the pointing module is changed, the automatically changed position of the magnet unit can be calibrated as a reference coordinate. Brief Description of the Drawings

[18] Fig. 1 is a conceptual perspective view of an electronic device according to an embodiment of the present invention;

[19] Fig. 2 is a conceptual block diagram of an information processing unit according to the embodiment of the present invention;

[20] Fig. 3 is a sectional view of a pointing module according to the embodiment of the present invention;

[21] Fig. 4 is a plan view of the pointing module according to the embodiment of the present invention;

[22] Fig. 5 is a conceptual block diagram of a sensing chip according to the embodiment of the present invention;

[23] Fig. 6 is a flowchart illustrating cursor movement operation of the electronic device according to the embodiment of the present invention;

[24] Fig. 7 is a flow chart illustrating determination or correction operation of reference coordinate information according to the embodiment of the present invention;

[25] Fig. 8 is a flow chart illustrating determination or correction operation of reference coordinate information according to a modification of the embodiment of the present invention; and

[26] Fig. 9 is a flow chart illustrating determination or correction operation of reference coordinate information according to another modification of the embodiment of the present invention. Best Mode for Carrying Out the Invention

[27] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented into different forms. These embodiments are provided only for illustrative purposes and for full understanding of the scope of the present invention by those skilled in the art. Throughout the drawings, like reference numerals are used to designate like elements.

[28] Fig. 1 is a conceptual perspective view of an electronic device according to an embodiment of the present invention. Fig. 2 is a conceptual block diagram of an information processing unit according to the embodiment of the present invention. Fig. 3 is a sectional view of a pointing module according to the embodiment of the present invention, and Fig. 4 is a plan view of the pointing module according to the embodiment of the present invention. Fig. 5 is a conceptual block diagram of a sensing chip according to the embodiment of the present invention. Fig. 6 is a flowchart illustrating cursor movement operation of the electronic device according to the embodiment of the present invention. Fig. 7 is a flow chart illustrating determination or correction operation of reference coordinate information according to the embodiment of the present invention. Fig. 8 is a flow chart illustrating determination or correction operation of reference coordinate information according to a modification of the embodiment of the present invention. Fig. 9 is a flow chart illustrating determination or correction operation of reference coordinate information according to another modification of the embodiment of the present invention.

[29] Referring to Figs. 1 to 9, the electronic device according to the embodiment of the present invention includes an image display unit 1000, an information processing unit 2000 and a pointing module 3000. As shown in Fig. 1, the electronic device further includes a plurality of input units 4000.

[30] In addition, the electronic device further includes cases 5100 and 5200 for accommodating the image display unit 1000, the information processing unit 2000, the pointing module 3000 and the plurality of input units 4000, and a power supply 5000 for supplying power to the image display unit 1000, the information processing unit 2000 and the pointing module 3000.

[31] The image display unit 1000 displays an image using an image signal from the information processing unit 2000 and displays a cursor at a predetermined position in the image.

[32] As shown in Fig. 2, the information processing unit 2000 includes an image signal generation module 2100 for generating an image signal using image information; a cursor coordinate generation module 2200 for generating a cursor coordinate signal in accordance with an output signal of the pointing module 3000; a memory 2300 for storing plural pieces of information including input information and image information provided from the plurality of input units 4000; and a control module 2400 for controlling operation of the respective components.

[33] As shown in Fig. 3, the pointing module 3000 includes a magnet unit 3300; an operating member 3400 for moving the magnet unit 3000 through user's movement; a medium member 3200 for moving, rotating and restoring the magnet unit 3300 and the operating member 3400; and a sensor chip 3500 for generating a predetermined sensing signal and reference coordinate information (i.e., zero-point information) by sensing magnetic variations according to movement of the magnet unit 3300. Moreover, the pointing module 3000 further includes a substrate 3100 for fixedly supporting the medium member 3200 and allowing the sensor chip 3500 to be mounted thereon. The reference coordinate means a coordinate, which becomes a reference to calibrate a coordinate value, and denotes a zero point (0, 0).

[34] As shown in Fig. 5, the sensor chip 3500 of this embodiment includes a sensor 3510 for outputting a sensing signal based on movement of the magnet unit 3300; a reference coordinate generator 3520 for generating a reference coordinate using a sensing signal; a storage unit 3530 for storing the reference coordinate; and a controller 3540 for controlling operation of the sensor 3510, the reference coordinate generator 3520 and the storage unit 3530, and outputting a sensing signal and a reference coordinate signal. Here, the controller 3540 provides the information processing unit 2000 with the sensing signal and the reference coordinate signal. Alternatively, the controller 3540 may provide the information processing unit 2000 with a signal corresponding to movement of the magnet unit 3300 using the sensing signal and the reference coordinate signal.

[35] As shown in Fig. 4, the sensor 3510 of the sensor chip 3500 includes a plurality of magnetic sensors 3510-xl, 3510-x2, 3510-yl and 3510-y2. At this time, hall elements, in which an output voltage is changed in proportion to magnetic flux density, are used as the magnetic sensors. However, the present invention is not limited thereto. That is, any ones of semiconductor magnetic resistive elements, ferromagnetic resistive elements and giant magneto resistive (GMR) elements may be used as the magnetic sensors 3510-xl, 3510-x2, 3510-yl and 3510-y2.

[36] As shown in Fig. 4, the sensor 3510 includes the first and second X-axis magnetic sensors 3510-xl and 3510-x2 for sensing a magnetic variation in an X-axis direction and outputting an X-coordinate value corresponding to the sensed magnetic variation; and the first and second Y-axis magnetic sensors 3510-yl and 3510-y2 for sensing a magnetic variation in a Y-axis direction and outputting a Y-coordinate value corresponding to the sensed magnetic variation. The sensor 3510 may further include an amplifier (not shown) for amplifying output values of the magnetic sensors 3510-xl, 3510-x2, 3510-yl and 3510-y2 and outputting the amplified output values as the sensing signals.

[37] As such, in the pointing module 3000 of this embodiment, output values of the first and second X-axis magnetic sensors 3510-xl and 3510-x2 and the first and second Y- axis magnetic sensors 3510-yl and 3510-y2 are changed depending on movement of the magnet unit 3300 roughly positioned at the center of the medium member 3200 (i.e., movement of the operating member 3400).

[38] In this embodiment, a reference coordinate generator 3520 for generating a reference coordinate is provided in the sensor chip 3500. Just after the pointing module 3000 is assembled, the reference coordinate generator 3520 generates reference coordinate information using a sensing signal of the sensor 3510 and stores the generated information in the storage unit 3530.

[39] That is, in a conventional information processing unit, a coordinate value corresponding to a sensing signal value provided from the pointing module 3000 in booting of an electronic device was calibrated as reference coordinate information. However, the reference coordinate information is reference coordinate information calibrated when assuming that the magnet unit 3300 of the pointing module 3000 does not move in booting of the electronic device. As described in the background art, when the magnet unit 3300 is moved by a user or external force, erroneous reference coordinate information may be calibrated. Therefore, although the magnetic unit 3300 is not moved by a user in the normal operation of the electronic device, a cursor on a screen may be moved.

[40] Accordingly, in this embodiment, an additional storage unit 3530 is further provided in the sensor chip 3500 of the pointing module 3000, and reference coordinate information generated in the reference coordinate generator 3520 is stored in the storage unit 3530. In addition, the pointing module 3000 provides the stored reference coordinate information to the information processing unit 2000 when the electronic device is booted.

[41] At this time, the storage unit 3530 preferably includes a storage device capable of storing corresponding information even though external power is not applied. EPROM, EEPROM or a flash memory may be used as the storage device.

[42] Further, the reference coordinate generator 3520 may correct reference coordinate information by automatically determining whether or not the pointing module 3000 operates, or may correct reference coordinate information in accordance with control signals of the controller 3540.

[43] As described above, the information processing unit 2000, which receives a sensing signal and reference coordinate information from the pointing module 3000, calculates a movement coordinate corresponding to the movement of the magnet unit 3300 (i.e., movement of the operating member 3400), and allows a current cursor on a screen to move based on the calculated movement coordinate. Here, the reference coordinate information becomes a reference for determining how far the magnet unit 3300 is moved based on a reference coordinate.

[44] It will be apparent that the pointing module 3000 of this embodiment is not limited to the aforementioned configuration but may be variously modified. For example, a pointing input device in the form of a ball mouse may be used as the pointing module 3000. Alternatively, a pointing module capable of calculating a coordinate in accordance with variation of light by using an optical sensor may be used. In this case, a ball or a light source may be used rather than the magnet unit 3300. Preferably, the sensor chip 3500 senses a movement of a ball or a variation of light.

[45] Hereinafter, the cursor movement operation of the electronic device according to this embodiment will be described below with reference to Fig. 6.

[46] If the magnet unit 3300 of the pointing module 3000 is moved by a user or external force (i.e., the operating member 3400 is moved), a sensing signal corresponding to a range of the movement is generated (SlO). The controller 3520 of the pointing module 3000 provides the information processing unit 2000 with the sensing signal and reference coordinate information (S20). At this time, since the reference coordinate information is provided at the time when the electronic device is turned on, only the sensing signal may be provided when the magnet unit 3300 moves. The cursor coordinate generation module 2200 of the information processing unit 2000 generates cursor movement coordinate information by using the sensing signal and the reference coordinate information (S30). The generated cursor movement coordinate information is provided in the image signal generation module 2100, thereby allowing a cursor on an image of the image display unit 1000 to be moved based on the cursor movement coordinate information (S40).

[47] As such, the electronic device of this embodiment does not separately calculate reference coordinate information by using the information processing unit 2000, but receives the reference coordinate information stored in the storage unit of the pointing module 3000 to generate cursor movement coordinate information for controlling the movement of the cursor.

[48] Here, the reference coordinate information is determined or corrected during a process of assembling the pointing module 3000 or at a booting point of time just after the assembling process (i.e., an initial booting point of time), and then stored in the storage unit 3530 of the pointing module 3000. However, the present invention is not limited thereto. That is, the reference coordinate information may be generated and stored by the sensor chip 3500 of the pointing module 3000 during the process of assembling the pointing module 3000 in the electronic device or at the time when the electronic device is booted just after the assembling process. Alternatively, the pointing module 3000 may calculate reference coordinate information and store the information before the assembled electronic device comes into the market.

[49] Hereinafter, the determination or correction operation of reference coordinate information in the sensor chip 3500 of the pointing module 3000 will be described with reference to Fig. 7.

[50] The sensor chip 3500 determines whether or not the current operation is performed in the initial booting (Sl 10). That is, the sensor chip 3500 determines whether or not power is initially provided to the pointing module 3000. If the electronic device is not initially booted, the operation for determining reference coordinate information is ended. In a case of the initial booting, the reference coordinate generator 3520 of the sensor chip 3500 receives a sensing signal from the sensor 3510 (S 120). At this time, the sensing signal preferably includes four output values respectively outputted from the first and second X-axis magnetic sensors 3510-xl and 3510-x2 and the first and second Y-axis magnetic sensors 3510-yl and 3510-y2. The reference coordinate generator 3520 may directly receive the sensing signal from the sensor 3510, or may receive the sensing signal through the controller 3540. The reference coordinate generator 3520 that receives the sensing signal generates a reference coordinate corresponding to the sensing signal (S 130). In the sensing signal, the output value of the first X-axis magnetic sensor 3510-xl may be a positive X-axis coordinate value, and the output value of the second X-axis magnetic sensor 3510-x2 may be a negative X- axis coordinate value. Also, in the sensing signal, the output value of the first Y-axis magnetic sensor 3510-yl may be a positive Y-axis coordinate value, and the output value of the second Y-axis magnetic sensor 3510-y2 may be a negative Y-axis coordinate value. Accordingly, the reference coordinate can be generated. However, the present invention is not limited thereto. That is, the reference coordinate may be determined by various methods. The sensor chip 3500 stores the generated reference coordinate in the storage unit 3530 (S 140).

[51] However, the present invention is not limited thereto. That is, the reference coordinate generator 3520 of the sensor chip 3500 of this embodiment may sequentially receive a plurality of sensing signals by a certain period to generate a plurality of reference coordinates, and store an average thereof as an initial reference coordinate.

[52] That is, as shown in the modification of Fig. 8, the controller 3540 of the sensor chip 3500 determines whether or not the current operation is performed in the initial booting (S210). If the electronic device is not initially booted, the operation for determining reference coordinate information is ended. In a case of the initial booting, the controller 3540 calibrates a weighted value (n) as zero (S220). Then, the reference coordinate generator 3520 receives a sensing signal from the sensor 3510 (S230). It is determined whether or not the weighted value (n) is equal to a calibration value (k) (S240). At this time, if the weighted value (n) is smaller than the calibration value (k), the reference coordinate generator 3520 generates a reference coordinate corresponding to the applied sensing signal (S250). Then, the generated reference coordinate is temporarily stored (S260). Subsequently, one is added to the weighted value (n) (S270), and the reference coordinate generator 3520 then receives another sensing signal. At this time, if the operation is repeatedly performed as many times as the calibration value (k), the weighted value (n) becomes equal to the weighted value (k). For example, when the calibration value (k) is 5, the reference coordinate generator 3520 receives a sensing signal five times to generate five reference coordinate values corresponding to the respective sensing signals, and temporarily stores the generated reference coordinate values in the storage unit 3530 or controller 3540.

[53] If the weighted value (n) is equal to the calibration value (k), the reference coordinate generator 3520 or controller 3540 calculates an average of the reference coordinate values temporarily stored in the storage unit 3530 (S280). The reference coordinate generator 3520 or controller 3540 stores the calculated average reference coordinate value as reference coordinate information in the storage unit 3530 (S290). As described in this modification, the reliability of a calibration value of reference coordinate information can be improved by receiving a plurality of sensing signals, generating a plurality of reference coordinate values, and storing an average thereof as reference coordinate information.

[54] In addition, the present invention is not limited thereto. That is, a user may provide the pointing module 3000 with a separate reference coordinate calibration command, thereby performing determination or correction of the reference coordinate information.

[55] That is, instead of the initial booting determination step of Figs. 7 and 8, it is determined whether or not a user provides a reference coordinate calibration command. If the reference coordinate calibration command is not provided, reference coordinate correction is not performed. On the other hand, if the reference coordinate calibration command is provided, a reference coordinate is automatically corrected, and the corrected reference coordinate is stored in the storage unit 3530 as shown in the flowcharts described in Figs. 7 and 8.

[56] However, the present invention is not limited thereto. For example, the pointing module 3000 of this embodiment may continuously and automatically correct a reference coordinate not when the electronic device having the pointing module 3000 mounted thereto is booted but while the electronic device operates. That is, during the operation of the electronic device, the pointing module 3000 performs determination or correction of a reference coordinate while a user does not move an instrument unit (i.e., the magnet unit 3300) of the pointing module 3000.

[57] When the magnet unit 3300 is locally deformed due to the continuous use of the pointing module 3000, the position of the magnet unit 3300 of the pointing module 3000 may be changed. At this time, the position of the magnet unit 3300 changed due to the deformation may be calibrated as a reference coordinate point by automatically correcting a reference coordinate while the user does not use the pointing module 3000 as described above.

[58] As shown in Fig. 9, it is determined whether or not the user operates the pointing module 3000 (S310). That is, it is determined whether or not the position of the magnet unit 3300 is changed. At this time, whether the position of the magnet unit 3300 is changed may be determined by various methods. In this embodiment, whether the position of the magnet unit 3300 is changed is preferably determined by determining whether or not a sensing signal outputted from the sensor 3510 is changed. That is, when the sensing signal maintains a constant value for a predetermined period (e.g., a few seconds (minimum 1 second) to a few tens hours (maximum 1000 hours)), it is determined that the position of the magnet unit 3300 is not changed.

[59] When it is resultantly determined that the user changes the position of the magnet unit 3300 of the pointing module 3000, the operation of automatically correcting a reference coordinate is stopped. As described in Fig. 6, the operation for moving a cursor is then performed. On the other hand, when it is resultantly determined that the user does not change the position of the magnet unit 3300 of the pointing module 3000, the reference coordinate generator 3520 of the sensor chip 3500 receives a sensing signal from the sensor 3510 (S320). The reference coordinate generator 3520 generates a reference coordinate corresponding to the sensing signal (S330). The generated reference coordinate is stored as new reference coordinate information in the storage unit 3530.

[60] As such, the pointing module 3000 of this embodiment automatically performs the reference coordinate correction when or after the pointing module 3000 is assembled, performs the reference coordinate correction in accordance with a user's demand, or automatically performs the reference coordinate correction while a user does not operate the pointing module 3000, thereby preventing an erroneous reference coordinate signal from being generated due to user's operation of the pointing module 3000 when the reference coordination correction is performed. Further, the reference coordinate correction is stored in the storage unit 3530 that is a nonvolatile memory device, thereby preventing a reference coordinate signal from being deleted even though the electronic device is turned off. Accordingly, the separate operation for correcting a reference coordinate cannot be performed while the electronic device is booted, and the reference coordinate signal stored in the storage unit 3530 can be immediately used.

[61] In addition, the electronic device of this embodiment may include a mobile phone, a camera, a camcorder, an MP3, a portable multimedia player, a computer, a notebook computer, and the like. Here, a variety of components suitable for functions of the electronic device may be further added to the electronic device. For example, when a mobile phone is used as the electronic device, the electronic device may further include a wireless communication module for controlling reception/transmission of voice and control data; and a voice processing module for converting voice data received by the wireless communication module into audible sounds and outputting the audible sounds through a speaker unit, or for digitalizing voice received from a microphone and outputting the digitalized voice to a wireless unit.

[62] Although the present invention has been described in connection with the accompanying drawings and the preferred embodiment, the present invention is not limited thereto but defined by the appended claims. Accordingly, it will be understood by those skilled in the art that various modifications and changes can be made thereto without departing from the spirit and scope of the invention defined by the appended claims.

Claims

[1] A method for calibrating a zero point of a pointing module, comprising the steps of: determining whether or not a reference coordinate calibration command is provided from an outside; calibrating a sensing signal outputted from a sensor as a reference coordinate (i.e., zero point); and storing the calibrated reference coordinate in a storage unit.

[2] A method for calibrating a zero point of a pointing module, comprising the steps of: determining whether or not a position of an operating member is changed; receiving a sensing signal from a sensor to calibrate a new reference coordinate when the position of the operating member is not changed; and renewing an initial reference coordinate of a storage unit as the new reference coordinate.

[3] The method as claimed in claim 2, wherein the determination of the change of the position of the operating member is performed using whether or not the sensing signal is changed, it is determined that the position of the operating member is not changed when the sensing signal has the same signal value for a position change sensing period, and it is determined that the position of the operating member is changed when the sensing signal has a changed signal value for the position change sensing period.

[4] A method for calibrating a zero point of a pointing module, comprising the steps of: assembling a pointing module; booting the pointing module; calibrating a sensing signal outputted from a sensor of the pointing module as a reference coordinate (i.e., zero point); and storing the calibrated reference coordinate in a storage unit.

[5] The method as claimed in any one of claims 1, 2 and 4, wherein the step of calibrating a sensing signal as a reference coordinate comprises the steps of: receiving a plurality of sensing signals for a sensing period to generate reference coordinates of the respective sensing signals; and calculating an average of the reference coordinates and calibrating the average as the reference coordinate.

[6] A pointing module, comprising: a sensor for sensing a movement of an operating member and outputting the sensed movement as a sensing signal; a reference coordinate generator for generating reference coordinate information using the sensing signal; a storage unit for storing the reference coordinate information therein; and a controller for controlling operation of the reference coordinate generator and the storage unit, and outputting the sensing signal and the reference coordinate information.

[7] The pointing module as claimed in claim 6, wherein the reference coordinate generator generates the reference coordinate information when the position of the operating member is not changed for a predetermined position change sensing period.

[8] The pointing module as claimed in claim 6, wherein the reference coordinate generator generates the reference coordinate information in accordance with a control signal of the controller.

[9] The pointing module as claimed in claim 6, wherein the storage unit includes any one of EPROM, EEPROM and a flash memory.

[10] An electronic device, comprising: an image display unit for displaying an image and a cursor; a pointing module for sensing a movement of an operating member to output the sensed movement as a sensing signal, generating reference coordinate information using the sensing signal, and storing the reference coordinate information; an information processing unit including an image signal generation module for controlling the image based on external image information, a cursor coordinate generation module for calculating a movement coordinate of the cursor using the sensing signal and the reference coordinate information to allow the cursor to be moved to the movement coordinate, and a control module for controlling operation of the image signal generation module, a memory, and the cursor coordinate generation module; and a power supply for supplying power to the pointing module, the image display unit and the information processing unit.

[11] The electronic device as claimed in claim 10, wherein the reference coordinate information is stored in a storage unit before the electronic device is launched.