Patent Publication Number: US-7714871-B2

Title: System and method for controlling display of mobile terminal

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to a mobile terminal and, more particularly, to a system and method for controlling a display unit of a mobile terminal. 
   2. Background of the Related Art 
   In general, screen information (data) to be displayed on a display unit of a mobile terminal is configured and stored in an external memory such as a Random Access Memory (RAM). There are two methods typically used to display the screen information stored in the external memory. 
   A first related art display method is shown in  FIG. 1 . In this first method, a controller, such as a central processing unit (CPU) is used to configure and output the screen information. More specifically, as shown in  FIG. 1 , a controller  13  records screen data in a screen output buffer (not shown) of an external memory  12 , reads the screen data from the screen output buffer, and outputs the data to a display unit  11 . 
   However, this reading/writing of display data from/into the external memory  12  and outputting data to the display unit  11  requires multiple clock cycles, thus restricting performance of the display unit  11 . More specifically, by using this first display method, the reading/writing time associated with the external memory  12  and the controller  13 , as well as a transfer rate between the external memory  12  and the controller  13 , limit the display speed, and thus the type of display unit that can be used with the related art mobile terminal. 
   A second related art display method is shown in  FIG. 2 . In this second method, screen data is configured by a controller and output by an external memory. More specifically, as shown in  FIG. 2 , a controller  23  configures screen data in a screen output buffer (not shown) of an external memory  22 , and the external memory  22  outputs the configured screen data directly to the display unit  21 . 
   This second related art display method is advantageous in that a lesser number of clock cycles are required for the transfer of screen information, and display data can be output to the display unit  21  more quickly than in the first related art display method. 
   However, this second related display method suffers deficiencies similar to this first method, in that performance of the display unit is still somewhat limited by the reading/writing time required by the external memory  22 , a transfer rate between the external memory  22  and the controller  23 , and a transfer rate between the external memory  22  and the display unit  21 . 
   Thus, when screen data is configured in an external memory in accordance with these related art display methods, performance of the display unit is limited by the performance of the external memory and the interface speed. That is, since the output speed of the display unit is limited by a reading/writing time from/into the external memory by the controller, a data transfer rate between the external memory and the controller, and a data transfer rate between the external memory and the display unit, the related art mobile terminal cannot take advantage of the enhanced display capabilities associated with a high performance display unit. 
   SUMMARY OF THE INVENTION 
   An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter. 
   To achieve at least the above objects in whole or in parts, there is provided a system for controlling display of a mobile terminal including: a display unit for displaying various screen data; and a controller having a screen output buffer for the display unit and outputting screen data stored in the screen output buffer directly to the display unit. 
   Preferably, the controller includes: a screen output buffer allocated for a certain region of the internal memory; and a display interface for transmitting screen data outputted from the screen output buffer to the display unit. 
   Preferably, the internal memory is a random access memory (RAM). 
   To achieve at least these advantages in whole or in parts, there is further provided a method for controlling display of a mobile terminal including: allocating a screen output buffer in an internal memory; configuring screen data in the screen output buffer when screen information is inputted from outside; and reading by a controller screen data from the screen output buffer and outputting it directly to a display unit when the screen data configured in the screen output buffer is requested to be outputted. 
   Preferably, writing and reading operation of the screen output buffer is performed according to a clock cycle of an internal bus of the controller and the read screen data is outputted through a display interface of the controller. 
   To achieve at least these advantages in whole or in parts, there is further provided a system for controlling display of a mobile terminal, including a display unit configured to display screen data on a screen of the display unit, and a controller comprising a screen output buffer portion configured to receive and to store screen data, wherein the controller is configured to output screen data stored in the screen output buffer portion directly to the display unit. 
   To achieve at least these advantages in whole or in parts, there is further provided a method for controlling a display of a mobile terminal, including allocating a screen output buffer portion in an internal memory of a controller of the mobile terminal, configuring screen data in the screen output buffer portion when screen information is input from an external source, and reading screen data from the screen output buffer portion of the controller and outputting the screen data directly to a display unit of the mobile terminal in response to a request for the screen data configured in the screen output buffer to be output, wherein reading the screen data and outputting the screen data is done by the controller. 
   To achieve at least these advantages in whole or in parts, there is further provided a system for controlling a mobile terminal, including a controller which transmits screen data to a display of the terminal, and a memory included within the controller for storing the screen data. 
   To achieve at least these advantages in whole or in parts, there is further provided a method for controlling a mobile terminal, including storing screen data in an internal memory of a controller, and transmitting the screen data from the memory to a display of the terminal. 
   To achieve at least these advantages in whole or in parts, there is further provided a mobile terminal, including a display unit, and a controller having an internal memory for storing screen data and an interface which transfers the screen data from the memory to the display unit. 
   Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements, wherein: 
       FIG. 1  shows a related art display control system in accordance with a first related art display method; 
       FIG. 2  shows a related art display control system in accordance with a second related art display method; 
       FIG. 3  shows a system for controlling a display of a mobile terminal in accordance with an embodiment of the invention; and 
       FIG. 4  is a flow chart of a method for controlling a display of a mobile terminal in accordance with an embodiment of the invention. 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   A system and method for controlling a high performance display unit of a mobile terminal by using a memory provided in a controller, such as, for example, a CPU, is provided. In this system and method, screen output data is configured by an internal memory of the controller, and not by an external memory of the controller, and screen output data is transmitted directly from the internal memory to the display unit. Further, the screen output buffer, which is, in the related art, allocated to the external memory of the controller, is instead allocated to the internal memory region of the controller, and an interface is provided which allows the screen output data to be output directly from the controller to the display unit. Using this system and method, screen information (data) may be configured and transmitted based on a bus clock cycle of a high speed controller so as to fully utilize the enhanced display characteristics associated with a high performance display unit. 
   As shown in  FIG. 3 , a display control system in accordance with an embodiment of the invention includes a controller  30  for outputting screen information (data). The screen information is stored in an internal memory  31  of the controller  30 , and is output through a display interface  32 . A display unit  40  is provided for displaying the screen information output by the controller  30 . 
   A screen output buffer  31   a  for temporarily storing data to be output to the display unit  40  is allocated a predetermined region of the internal memory  31 . The internal memory  31  may be a RAM, or any other such data storage device. Data writing/reading to/from the screen output buffer  31   a  is performed based on an internal bus clock cycle of the controller  30 . The output buffer and internal memory may be located within a same chip, package, or module as other circuits of the controller, as well as the same printed circuit board. The display interface may also be located on the same chip, package, module, or board. 
   The operation of the system for controlling display of a mobile terminal constructed as described above will now be described with reference to  FIGS. 3 and 4 . 
   As shown in  FIG. 4 , a predetermined region of the internal memory  31  is allocated as a region for the screen output buffer  31   a  (step S 10 ). The predetermined region allocated for the screen output buffer  31   a  may be determined by a manufacturer. 
   When screen information is provided by, for example, an external source, the controller  30  configures the screen data by storing the input screen information in the screen output buffer  31   a  (step S 11 ). The screen data stored in the screen output buffer  31   a  is continuously changed based on input screen information, and reading/writing of data from/to the screen output buffer  31   a  is performed based on an internal bus clock cycle associated with a control bus of the controller  30 . 
   Thereafter, the controller  30  checks for a request to output or to change the configured screen data (step S 12 ). If a request for outputting or changing the screen data is detected, the controller  30  changes the screen data stored in the screen output buffer  31   a  (step S 13 ) and outputs the changed screen data to the display interface  32  via the screen output buffer  31   a  (step S 14 ). A data bus is provided for transmitting and receiving the screen data between the internal memory  31  and the display interface  32 . Once the screen data is received by the display interface  32 , the display interface  32  can transmit screen data to the display unit  40 . Thus, screen data transferred to the display interface  32  through the data bus after being read from the screen output buffer  31   a  is transferred to the display unit  40  through the data bus, thereby updating the screen of the display unit  40  (step S 15 ). 
   In this manner, screen data stored in the internal memory is output directly to the external display unit based on a clock cycle of the controller. This allows for a high transfer rate of the screen data due to the high processing rate of the internal memory. Thus, screen data can be displayed and updated on a high performance display unit at an optimum speed. 
   As embodied and broadly described herein, the system and method for controlling a high performance display unit used for a mobile terminal have the following advantages. 
   That is, the internal memory of the controller includes a screen output buffer region to store screen data, and the stored screen data is directly transmitted to the display unit, thereby increasing display speed. 
   Therefore, the system and method for controlling a display unit of a mobile terminal as embodied and broadly described herein is capable of improving an output speed of a display unit, and of achieving optimum screen output efficiency by using a high performance display unit. 
   The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures.