Abstract:
Disclosed is an apparatus for realizing an alarm function using a mobile terminal and a charging device for charging the mobile terminal. The mobile terminal includes a controller for generating an alarm control signal a predetermined time period ahead of a predetermined alarm time, and a first interface for transmitting the alarm control signal to the charging device. The charging device includes a second interface for receiving the alarm control signal from the mobile terminal, and a lamp driver for generating a lamp driving signal for controlling a lamp in response to the received alarm control signal.

Description:
PRIORITY 
   This application claims priority under 35 U.S.C. § 119 to an application entitled “Apparatus and Method for Realizing Alarm Function in a Charging Device for a Mobile Terminal” filed in the Korean Industrial Property Office on Feb. 19, 2003 and assigned Serial No. 2003-10355, the contents of which are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to the realization of an alarm function using a mobile terminal and a charging device for the mobile terminal, and in particular, to an apparatus and method for realizing a visual alarm function. 
   2. Description of the Related Art 
   A mobile terminal includes a battery pack for supplying electric power to the mobile terminal, and the battery pack is recharged using a charging device. 
   Recently, as many multifunctional electronic products are put on the market, there have been many demands for integrating various functions of the electronic products into one electronic product, for the sake of portability and utilization. However, most charging devices have only a charging function, being unable to meet such demands. 
   In general, a mobile terminal has an alarm function. The alarm function generates a predetermined sound through a speaker at a time previously set by a user, in order to inform the user of arrival of the set time. The alarm function is typically used as a morning call function. However, the sound alarm inconveniences the user, since he or she must turn on a lamp in the case of the night time, in order to respond to the alarm. In addition, the abrupt sound alarm and the light of the lamp may undesirably stress the user. 
   SUMMARY OF THE INVENTION 
   It is, therefore, an object of the present invention to provide a charging device for a mobile terminal, for realizing a visual alarm function. 
   It is another object of the present invention to provide a charging device with a visual alarm function for a mobile terminal, in which brightness of an alarm lamp is gradually adjustable. 
   To achieve the above and other objects, there is provided an apparatus for realizing an alarm function using a mobile terminal and a charging device for charging the mobile terminal. The mobile terminal includes a controller for generating an alarm control signal at a predetermined time period ahead of a predetermined alarm time, and a first interface for transmitting the alarm control signal to the charging device. The charging device includes a second interface for receiving the alarm control signal from the mobile terminal, and a lamp driver for generating a lamp driving signal for controlling a lamp in response to the received alarm control signal. 
   To achieve the above and other objects, there is provided a method for realizing an alarm function using a mobile terminal and a charging device for charging the mobile terminal. In the method, the mobile terminal generates an alarm control signal at a predetermined time period ahead of a predetermined alarm time, and transmits the alarm control signal to the charging device via a first interface. The charging device receives the alarm control signal from the mobile terminal via a second interface, and generates a lamp driving signal for controlling a lamp in response to the received alarm control signal. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, 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  illustrates a charging device according to a preferred embodiment of the present invention; 
       FIG. 2  is a block diagram of a mobile terminal according to a preferred embodiment of the present invention; 
       FIG. 3  is a block diagram illustrating the charging device of  FIG. 1  according to a preferred embodiment of the present invention; 
       FIG. 4  is a graph illustrating an alarm lamp driving signal according to a preferred embodiment of the present invention; and 
       FIG. 5  is a flowchart illustrating a procedure for performing a visual alarm function according to a preferred embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Several 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 are depicted in different drawings. In the following description, a detailed description of known functions and configurations incorporated herein has been omitted for conciseness. 
     FIG. 1  illustrates a charging device according to a preferred embodiment of the present invention. Referring to  FIG. 1 , a charging device  1  includes a cradle  3  on which a mobile terminal is put, and a pair of charging terminals  5  formed on the cradle  3 . The charging terminals  5  electrically contact with associated charging terminals of the mobile terminal so as to charge a battery pack for the mobile terminal. Further, the cradle  3  includes an interface jack  7 . The interface jack  7  is electrically connected to an associated interface connector of the mobile terminal, in order to receive an alarm control signal output from the mobile terminal. For the interface jack  7 , an 8 or 16-pin data link cable for data transmission is typically used. 
   In addition, the charging device  1  includes charging state indication lamps  9  for indicating a charging state of the mobile terminal being charged, and an alarm lamp  11  for giving a visual alarm. The alarm lamp  11  has a size small enough to be mounted on the charging device  1 , and has brightness that can be perceived by the user. Although a halogen lamp is typically used as the alarm lamp  11 , other lamps that satisfy the conditions stated above can also be used. 
     FIG. 2  is a block diagram of a mobile terminal according to a preferred embodiment of the present invention. Referring to  FIG. 2 , a mobile terminal  2  includes a controller  201 , a display  203 , a keypad  205 , a memory  207 , an audio processor  209 , an RF (Radio Frequency) module  211 , and an interface  213 . 
   The controller  201  controls the overall operation of the mobile terminal  2 . In particular, according to the present invention, the controller  201  generates the alarm control signal at an alarm time set by the user. The RF module  211 , under the control of the controller  201 , demodulates a radio signal including audio data and control data, received from an antenna (AT), and modulates a transmission signal to be transmitted through the antenna. The audio processor  209 , under the control of the controller  201 , converts audio data received from the RF module  211  into an audible sound through a speaker (SPK), converts an audio signal received from a microphone (MIC) into digital audio data, and provides the digital audio data to the RF module  211 . Particularly, in the invention, the audio processor  209  can generate an audible alarm signal through the speaker at an alarm time set by the user. 
   The keypad  205  includes a plurality of numerical keys and function keys, and provides the controller  201  with key input data corresponding to a key input by the user. The display  203  displays various messages under the control of the controller  201 . The memory  207  stores program data required to control an operation of the mobile terminal  2 , and also stores data generated during the control or generated by the user. Particularly, in the invention, the memory  207  stores the alarm time set by the user, time information for driving a visual alarm, and time information for ending the visual alarm. The interface  213  includes an interface connector (not shown) for connecting to the interface jack  7  of the charging device  1 , and provides the charging device  1  with the alarm control signal generated by the controller  201 . The interface  213  can be realized with a GPIO (General Purpose Input/Output) port. 
     FIG. 3  is a block diagram illustrating the charging device of  FIG. 1  according to a preferred embodiment of the present invention. Referring to  FIG. 3 , a mobile terminal sensor  303  determines whether the mobile terminal  2  is put on the cradle  3  of the charging device  1 , and a voltage detector  305  detects a voltage currently charged in a battery pack for the mobile terminal  2 . A voltage converter  311  converts an input AC (Alternating Current) voltage into a DC (Direct Current) voltage for driving a controller  319 . A charger  307 , under the control of the controller  319 , converts the DC voltage output from the voltage converter  311  into a charging voltage, and charges a battery pack for the mobile terminal  2  with the charging voltage. 
   The controller  319  controls the overall operation of the charging device  1 , and controls charging of the battery pack for the mobile terminal  2  by comparing a voltage detected by the voltage detector  305  with a preset voltage. A display  309 , under the control of the controller  319 , informs the user whether the charging operation is completed, through the charging state indication lamps  9 . An interface  317  includes the interface jack  7  for connecting to an associated interface connector of the mobile terminal  2 , and receives the alarm control signal provided from the mobile terminal  2 . 
   A lamp driver  315  drives an alarm lamp  313  in response to the received alarm control signal, under the control of the controller  319 . The lamp driver  315  will preferably gradually increase brightness of the alarm lamp  313  by controlling electric power supplied to the alarm lamp  313 , each time the alarm control signal is received from the interface  317 . A variable resistor or a triac (not shown) can be used to control the electric power supplied to the alarm lamp  313 . 
     FIG. 4  is a graph illustrating an alarm lamp driving signal according to a preferred embodiment of the present invention. In the graph, “A” represents a predetermined alarm time set by the user, and “X” represents a predetermined time period when a visual alarm, i.e. the alarm lamp  313 , is driven in advance of the alarm time A. As a result, the alarm lamp  313  is turned on for the time period X. In the present invention, the visual alarm is turned on at the time period X ahead of the alarm time A set by the user. In addition, “Y” represents a brightness level of the alarm lamp  313 . In the graph, the brightness level Y of the alarm lamp  313  is divided into  5  steps. Further, “Z” represents a visual alarm end time where the alarm lamp  313  is turned off. The values X, Y and Z may be previously set by the user. Alternatively, they can be previously set in the mobile terminal  2  by a manufacturer. 
     FIG. 5  is a flowchart illustrating a procedure for performing a visual alarm function according to a preferred embodiment of the present invention. A method for performing a visual alarm function using the mobile terminal  2  and the charging device  1  for the mobile terminal  2  will now be described with reference to  FIGS. 2 to 5 . 
   If a user desires to set the visual alarm function, the controller  201  of the mobile terminal  2  stores an alarm time A input by the user through the keypad  205  in the memory  207 . In addition, the controller  201  stores in the memory  207  the visual alarm time period X set by the user or manufacturer, the brightness information Y of the alarm lamp  313 , and the visual alarm end time Z. 
   If a visual alarm mode is set by the user, the controller  201  reads in step  501  the alarm time A and the visual alarm time period X from the memory  207 , and determines whether a current time is identical to a visual alarm start time (A–X). If the current time is identical to the visual alarm start time, the controller  201  proceeds to step  503 . Otherwise, if the current time has not arrived at the visual alarm start time, the controller  201  returns to the beginning of the procedure. 
   In step  503 , the controller  201  reads the brightness information Y and the visual alarm end time Z from the memory  207 , and calculates a time period for which a timer (not shown) is to be driven. The brightness information Y for a visual alarm preferably has a plurality of brightness steps y 1 , y 2 , y 3 , . . . for the visual alarm, and the number of brightness steps can be set by the user. For example, in  FIG. 4 , the  5  brightness steps are set. The timer is driven to repeatedly generate an alarm control signal at a predetermined interval. In the embodiment of the present invention, the alarm control signal is generated at an interval determined by dividing the visual alarm time period X by the visual alarm brightness Y information (i.e. X/Y). The controller  201  sets the driving time period of the timer to the time period X/Y so that the timer expires at intervals of the time period X/Y. 
   In step  505 , the controller  201  drives the timer, and then proceeds to step  507 . In step  507 , the controller  201  determines whether the timer has expired, i.e., whether the time period X/Y has elapsed. If the timer has expired, the controller  201  proceeds to step  509 . In step  509 , the controller  201  generates an alarm control signal, and provides the generated alarm control signal to the charging device  1  via the interface  213 . Upon receiving the alarm control signal via the interface  317 , the controller  319  of the charging device  1  enables the lamp driver  315  to turn on the alarm lamp  313 , initially in the lowest brightness step. 
   In step  511 , the controller  201  of the mobile terminal  2  determines whether the current time has arrived at the alarm time A. If the current time has not yet arrived at the alarm time A, the controller  201  returns to step  505  and drives the timer. In this case, the controller  201  provides the charging device  1  with the alarm control signal at intervals of the time period X/Y by repeating the process of steps  505  to  511 , until the current time arrives at the alarm time A. Each time the alarm control signal is received, the controller  319  of the charging device  1  enables the lamp driver  315  to increase the brightness of the alarm lamp  313 , step by step. 
   In the meantime, if the current time has arrived at the alarm time A, the controller  210  of the mobile terminal  2  preferably outputs an audio alarm signal to the speaker through the audio processor  209 , and then proceeds to step  513 . At the moment, the mobile terminal sensor  303  of the charging device  1  determines whether the mobile terminal  2  is on the cradle  3  of the charging device  1 . If the mobile terminal  2  is detached (or lifted up) from the charging device  1 , the mobile terminal sensor  303  provides a signal indicating detachment of the mobile terminal  2  to the controller  319  of the charging device  1 , and then proceeds to step  519 . 
   In step  519 , the controller  319  of the charging device  1  turns off the alarm lamp  313  by enabling the lamp driver  315  upon receiving the detachment signal of the mobile terminal  2 . If the mobile terminal  2  is detached from the charging device  1 , the controller  319 , will generate a mobile terminal detachment signal and release the visual alarm function by the charging device  1 , instead of proceeding to step  519 . If the visual alarm function is released, the alarm lamp  313  can be either continuously turned on or turned off by the controller  319  of the charging device  1 . 
   Although the present invention has been described only for the case where the mobile terminal sensor  303  determines whether the mobile terminal is detached from the charging device  1  after the alarm time, it will be understood by those skilled in the art that it is also possible to turn off the alarm lamp  313  or release the visual alarm function if the mobile terminal  2  is detached from the charging device  1 , even if the mobile terminal  2  is detached before the alarm time. 
   If it is determined in step  513  that the mobile terminal  2  is not detached from the charging device  1 , the controller  201  of the mobile terminal  2  determines in step  515  whether the current time is identical to the visual alarm end time Z. If the current time has not yet arrived at the visual alarm end time Z, the controller  210  of the mobile terminal  2  returns to step  513 . Otherwise, if the current time has arrived at the visual alarm end time Z, the controller  201  proceeds to step  517 . In step  517 , the controller  210  stops and resets the timer, generates a lamp off control signal for turning off the alarm lamp  313 , and transmits the lamp off control signal to the charging device  1  via the interface  213 . Upon receiving the alarm lamp off control signal via the interface  317  or receiving the mobile terminal detachment signal from the mobile terminal sensor  303 , the controller  319  of the charging device  1  disables the lamp driver  315  and turns off the alarm lamp  313 . 
   As can be understood from the foregoing description, the present invention realizes a visual alarm function in a charging device for a mobile terminal, thereby contributing to a decrease in stress that the user may suffer due to an abrupt sound alarm. In addition, the present invention adjusts brightness of a visual alarm step by step, inducing the user to wake up refreshingly. 
   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.