Patent Publication Number: US-2010115258-A1

Title: Image processing apparatus and control method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority from Korean Patent Application No. 10-2008-0109222, filed on Nov. 5, 2008 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     Apparatuses and methods consistent with the present invention relate to an image processing apparatus and a control method thereof processing an input image, and more particularly, to an image processing apparatus and a control method thereof having a configuration of processing data needed in a system booting. 
     2. Description of the Related Art 
     An image processing apparatus processes an image supplied from an image supplying source to be displayed in a display panel implemented by a liquid crystal, a plasma, etc. Since various functions for processing an image are provided to the image processing apparatus, the amount of data needed to be referred to by the image processing apparatus driving in system booting increases, and accordingly, time needed for the system booting of the image processing apparatus increases. 
     Various related art technologies are used to reduce a system booting time of the image processing apparatus. 
     For example, data for a system booting is packaged in a flash memory by a given standard, and this package is intactly loaded in a random access memory (RAM) in a system booting. This data package for booting is referred to a hibernation image or a snapshot image. 
     However, if the data amount of the hibernation image is large, a lot of time is needed to load the hibernation image in the RAM, and the system booting of the image processing apparatus is delayed. 
     SUMMARY OF THE INVENTION 
     According to an aspect of the present invention, there is provided an image processing apparatus, including: a storing unit in which booting data used for system booting of the apparatus is stored; a RAM in which the booting data is loaded from the storing unit; a central processing unit which loads the booting data in the RAM from the storing unit if system power supply to the apparatus is turned off, and refers to the booting data loaded in the RAM to perform the system booting if the system power supply is turned on; and a control unit which cuts off power supply to the central processing unit, and controls the RAM to operate in a low power mode in which power is supplied to the RAM to maintain the booting data loaded in the RAM while the system power supply is turned off 
     The control unit may monitor whether the RAM maintains the low power mode or not while the system power supply is turned off, and may input a selective logic signal corresponding to a monitoring result to the central processing unit if the system power supply is turned on. 
     The central processing unit may determine whether the RAM maintains the low power mode or not while the system power supply is turned off based on the logic signal input from the control unit, and may perform the system booting based on a determining result. 
     The central processing unit may refer to the booting data previously loaded in the RAM without loading the booting data from the storing unit if determining that the RAM maintains the low electric power mode, and may load the booting data from the storing unit to the RAM if determining that the RAM does not maintain the low power mode. 
     The central processing unit may examine an error of the booting data previously loaded in the RAM if determining that the RAM maintains the low power mode, and refers to the booting data previously loaded in the RAM without loading the booting data in the RAM from the storing unit, and may load the booting data from the storing unit in the RAM if determining that there is an error in the booting data previously loaded. 
     The control unit may transmit to the RAM a command ordering the RAM to enter the low power mode if determining that the booting data is loaded to the RAM after the system power supply is turned off 
     The storing unit may include a non volatile memory maintaining a data previously stored if electric power supply is broken. 
     Another aspect of the present invention may be achieved by providing a method of controlling an image processing apparatus which includes a storing unit storing booting data used for system booting of the apparatus, a RAM in which the booting data is loaded, and a central processing unit which refers to the booting data to perform the system booting, the method including: loading the booting data in the RAM if system power supply to the apparatus is turned off, and cutting off power to the central processing unit and operating the RAM in a low power mode in which power is applied to the RAM to maintain the booting data loaded in the RAM while the system power supply is turned off; and causing the central processing unit to refer to the booting data loaded in the RAM to perform the system booting if the system power supply to the apparatus is turned on. 
     The operating the RAM in the low power mode may include monitoring whether the RAM maintains the low power mode or not while the system power supply is turned off, and the causing the central processing unit to refer to the booting data loaded in the RAM to perform the system booting may include inputting a selective logic signal corresponding to a monitoring result to the central processing unit. 
     The causing the central processing unit to refer to the booting data loaded in the RAM to perform the system booting further may include causing the central processing unit to selectively perform the system booting based on the logic signal input to the central processing unit. 
     The causing the central processing unit to selectively perform the system booting may include: referring to the booting data previously loaded in the RAM without loading the booting data to the RAM from the storing unit if a logic signal indicating that the RAM maintains the low electric power mode is received, and loading the booting data to the RAM from the storing unit if a logic signal indicating that the RAM does not maintain the low electric power mode is received. 
     The referring to the booting data previously loaded to the RAM may include: examining an error of the booting data previously loaded to the RAM if the logic signal indicating that the RAM maintains the low power mode is received, and loading the booting data from the storing unit to the RAM if it is determined that there is an error in the booting data previously loaded in the RAM. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a block diagram of an image processing apparatus according to an exemplary embodiment; 
         FIG. 2  is a flowchart illustrating a control method of the image processing apparatus in  FIG. 1 , according to an exemplary embodiment; 
         FIG. 3  is a flowchart of a central processing unit if system power supply is turned off in the image processing apparatus in  FIG. 1 , according to an exemplary embodiment; 
         FIG. 4  is a flowchart of the central processing unit if the system power supply is turned on in the image processing apparatus in  FIG. 1 , according to an exemplary embodiment; 
         FIG. 5  is a flowchart of a control unit if the system power supply is turned off in the image processing apparatus in  FIG. 1 , according to an exemplary embodiment; and 
         FIG. 6  is a flowchart of the control unit in case of turning on the system power supply while the system power supply is turned off in the image processing apparatus in  FIG. 1 , according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The exemplary embodiments are described below so as to explain the present invention by referring to the figures. Repetitive description with respect to like elements of different embodiments may be omitted for the convenience of clarity. 
       FIG. 1  is a block diagram of an image processing apparatus  1  according to an exemplary embodiment of the present invention. The image processing apparatus  1  according to the present exemplary embodiment may be implemented as various types, and for example, may be implemented as a television, a set top box, a media player replaying an optical storage medium such as a digital versatile disk (DVD) or a Blu-ray disk, a portable media player, etc. 
     As shown in  FIG. 1 , the image processing apparatus  1  according to the present exemplary embodiment performs system booting if a system power supply is turned on, and has various booting data referred to for the system booting. Here, the booting data includes various data which may be referred to in a booting, and is not limited to a specific type. The system power supply means power supply to the image processing apparatus  1  which may be implemented by turning on a system power supply unit such as a main power switch (not shown) included in the image processing apparatus  1 . 
     For system booting, the image processing apparatus  1  includes a storing unit  100  in which the booting data is stored, a RAM  200  in which the booting data is loaded, and a central processing unit  400  loading the booting data in the RAM  200  and referring to the booting data to perform system booting. Here, the central processing unit  400  loads the booting data in the RAM  200  if system power supply is turned off, and refers to the booting data previously loaded in the RAM  200  to perform the system booting if the system power supply is turned on. 
     Also, the image processing apparatus  1  further includes a control unit  500  applying to the RAM  200  electric power capable of maintaining the booting data previously loaded in the RAM  200  to operate the RAM  200  in a low electric power mode. Also, the image processing apparatus  1  may include an electric power supplying unit (not shown) supplying and cutting off electric power supply to each element of the image processing apparatus  1  according to control of the control unit  500 . 
     The image processing apparatus  1  may include various other elements as well as a display panel (not shown) displaying an image. Various known configurations may be employed thereto. 
     With the aforementioned configuration, the booting data can be maintained in the RAM  200  while the system power supply is turned off, and the booting data previously loaded in the RAM  200  can be referred to in system booting. Accordingly, time needed for loading the booting data in the RAM  200  from the storing unit  100  can be saved in the system booting. 
     Hereinafter, each element of the image processing apparatus  1  will be described. 
     The storing unit  100  stores various type applications, libraries, data, etc. which the central processing unit  400  executes and refers to in addition to the booting data. The storing unit  100  may be implemented as a non-volatile memory, for example, a flash memory, a hard disk drive (HDD), a solid state drive (SSD), etc. maintaining previously stored data although electric power supply is cut off. 
     Among the data stored in the storing unit  100 , data which is to be executed or referred to by the central processing unit  400  is loaded in the RAM  200 . That is, for data stored in the storing unit  100  to be executed or referred to by the central processing unit  400 , the corresponding data is initially loaded to the RAM  200 . 
     Unlike the storing unit  100 , the RAM  200  is a volatile memory not maintaining data previously loaded if electric power supply is cut off. Accordingly, in general, if the system power supply is turned off, electric power supply to the RAM  200  is cut off, and accordingly, the RAM  200  is initialized. 
     However, when certain data is loaded in the RAM  200 , the RAM  200  is capable of maintaining the loaded certain data by being applied with electric power required to maintain the certain data. This operating state of the RAM  200  refers to a low electric power mode, more in detail, a self refresh mode. 
     When the RAM  200  operates in the self refresh mode, the RAM  200  internally reads data loaded in a cell of the RAM  200  and writes the data in the cell again regularly, thereby maintaining the data previously loaded. Here, since there is no input and output of data with respect to the outside, electric power needed in the self refresh mode is smaller than electric power needed in a normal mode. For example, if the RAM  200  requires a current of 180 mA in the normal mode, approximately 5 mA is required in the self refresh mode. 
     For the RAM  200  to enter the self refresh mode from the normal mode, a logic signal of “low” (a “low” signal) is applied to a clock enable input pin  210  of the RAM  200 , and a command for entering the self refresh mode is received. The “low” signal and the command for entering the self refresh mode are output by the control unit  500 . 
     A user input unit  300  outputs a command input by a user for controlling an operation of the image processing apparatus  1 . According to an exemplary embodiment, an event of turning on or turning off of the system power supply is performed by generating a corresponding command through the user input unit  300  by a user. The user input unit  300  transmits this command to the central processing unit  400  and the control unit  500  to respectively perform a control operation depending on an event. The user input unit  300  may be implemented as a menu key (not shown) disposed at an outside of the image processing apparatus  1 , a remote controller (not shown), etc. 
     The central processing unit  400  controls overall operations of the image processing apparatus  1  including processing of an input image. The central processing unit  400  may include a decoder, a scaler, an enhancer, etc. for processing the input image, and a main processor, a memory controller, etc. for controlling subordinate elements of the image processing apparatus  1 . The central processing unit  400  may be implemented as a group including the aforementioned elements separately provided, or by an integrated chip. 
     Since various functions are integrated in the central processing unit  400 , power consumption of the central processing unit  400  is high. Accordingly, when the system power supply is turned off, it is preferable but not necessary that electric power supply to the central processing unit  400  is cut off. 
     If an event of turning off the system power supply occurs, the central processing unit  400  loads booting data stored in the storing unit  100  to the RAM  200 . If this process is completed, the control unit  500  cuts off the electric power supply to the central processing unit  400 . Then, if the system power supply is turned on, electric power is also applied to the central processing unit  400 , and accordingly, the central processing unit  400  performs system booting. 
     According to an exemplary embodiment, if the system power supply is turned on, the central processing unit  400  may perform two different booting processes based on a logic signal received from the control unit  500 . Hereinafter, each booting process will be described. 
     The central processing unit  400  includes a general purpose input/output (GPIO) pin  410  for receiving a signal from an outside. As the system power supply is turned on, electric power is applied to the central processing unit  400 , and the central processing unit  400  prepares system booting. Also, the control unit  500  outputs a logic signal of “low” (a “low” signal) or a logic signal of “high” (a “high” signal) to the GPIO pin  410  according to whether the RAM  200  maintains the low electric power mode or not while the system power supply is turned off 
     In the present exemplary embodiment, it is exemplarily described that the control unit  500  inputs a “high” signal if the RAM  200  maintains the low electric power mode, and the control unit  500  outputs a “low” signal if the RAM  200  does not maintain the low electric power mode. However, the present invention is not limited thereto. On the contrary, the control unit  500  may output the “low” signal if the RAM  200  maintains the low electric power mode, and may output the “high” signal if the RAM  200  does not maintain the low electric power mode. 
     When the central processing unit  400  prepares the system booting, if the “high” signal is applied to the GPIO pin  410 , the central processing unit  400  determines that the RAM  200  maintains the low electric power mode while the system power supply is turned off Since this means that the booting data is maintained in the RAM  200 , the central processing unit  400  omits a process of loading the booting data from the storing unit  100  in the RAM  200 , and refers to the booting data previously loaded in the RAM  200  to perform the system booting. This booting process refers to a warm booting. 
     On the contrary, if the “low” signal is input to the GPIO pin  410 , the central processing unit  400  determines that the RAM  200  does not maintain the low electric power mode while the system power supply is turned off Since this means that there is no booting data in the RAM  200 , the central processing unit  400  loads the booting data from the storing unit  100  in the RAM  200 , and then refers to the loaded booting data to perform the system booting. This booting process refers to a cold booting. 
     As described above, the central processing unit  400  may selectively perform the warm booting or the cold booting based on the logic signal input to the GPIO pin  410 . Here, the terms “warm booting” and “cold booting” are employed only for convenience of description, and do not limit the present invention thereto. 
     The central processing unit  400  examines an error of the booting data previously loaded in the RAM  200  before performing the warm booting. In the examination result, if there is no error, the central processing unit  400  performs the warm booting. On the contrary, if an error is examined, since the warm booting is incapable of being normally performed, the central processing unit  400  performs the cold booting. 
     If an event of turning off a system power supply occurs, the control unit  500  determines whether the booting data is loaded in the RAM  200  by the central processing unit  400  or not. If the booting data is loaded in the RAM  200 , the control unit  500  inputs a low signal to the clock enable input pin  210  of the RAM  200 , and transmits a low electric power mode entering command to the RAM  200 . Accordingly, the RAM  200  enters the low electric power mode. 
     While the system power supply is turned off, the control unit  500  monitors whether the RAM  200  maintains the low electric power mode. If an accident such as an electric power plug of the image processing unit  1  being pulled off occurs so that the RAM  200  fails to maintain the low electric power mode, the control unit  500  stores this environment change. For this, the control unit  500  may include a separate electrically erasable programmable read only memory (EEPROM). 
     If the system power supply is turned on, the control unit  500  applies a logic signal to the GPIO pin  410  of the central processing unit  400  based on the monitoring result. For example, if the RAM  200  maintains the low electric power mode while the system power supply is turned off, the control unit  500  may apply the “high” signal, and otherwise, may apply the “low” signal. Accordingly, the central processing unit  400  selects the warm booting or the cold booting to perform the system booting. 
     With this configuration, hereinafter, a control method of the image processing apparatus  1  according to the present exemplary embodiment will be described by referring to  FIG. 2 . 
       FIG. 2  is a flowchart schematically illustrating a control method of the image processing apparatus  1  according to an exemplary embodiment. 
     As shown in  FIG. 2 , at first, an event of turning off the system power supply occurs (S 100 ). Accordingly, the central processing unit  400  loads the booting data in the RAM  200  (S 110 ), and the control unit  500  makes the RAM  200  enter the low electric power mode (S 120 ). If this process is completed, the system power supply is turned off (S 130 ). 
     While the system power supply is turned off, the RAM  200  operates in the low electric power mode to maintain the loaded booting data (S 140 ). 
     If the system power supply is turned on (S 150 ), the central processing unit  400  refers to the booting data loaded in the RAM  200  to perform system booting (S 160 ). Accordingly, time needed for loading the booting data in the RAM  200  from the storing unit  100  in system booting can be saved, thereby reducing a system booting time. 
     Hereinafter, the control process in  FIG. 2  will be described more in detail by each process by referring to  FIGS. 3 to 6 . 
     At first, a control method of the central processing unit  400  in case of turning off the system power supply will be described.  FIG. 3  is a flowchart illustrating this process according to an exemplary embodiment. 
     As shown in  FIG. 3 , in an initial state that the system power supply is turned on, the central processing unit  400  receives a command to turn off the system power supply as an event of turning off the system power supply (S 200 ). 
     A method of transmitting the command to the central processing unit  400  is not limited. For example, a user may perform an input for turning off the system power supply through the user input unit  300 , and the user input unit  300  may generate a command corresponding thereto, and may transmit the command to the central processing unit  400 . 
     The central processing unit  400  loads the booting data stored in the storing unit  100  in the RAM  200  from the storing unit  100  (S 210 ). 
     If the loading of the booting data in the RAM  200  is performed, the system power supply is turned off, and accordingly, the electric power to the central processing unit  400  is cut off (S 220 ). Turning off the system power supply and cutting off the electric power supply to the central processing unit  400  may be performed by the control unit  500 , or the central processing unit  400  may transmit a control signal to an electric power supplying unit (not shown) supplying system power to the image processing apparatus  1  to perform turning off the system power supply and cutting off the electric power supply to the central processing unit  400 . 
     Then, a control process of the central processing unit  400  for performing system booting when the system power supply of the image processing apparatus  1  is turned on will be described.  FIG. 4  is a flowchart illustrating this process according to an exemplary embodiment. 
     As shown in  FIG. 4 , if the system power supply is turned on, the central processing unit  400  starts operating (S 300 ). 
     Before performing the system booting, the central processing unit  400  determines whether a signal is applied to the GPIO pin  410 , and whether the applied signal is a “high” signal (S 310 ). 
     If the “high” signal is applied to the GPIO pin  410 , the central processing unit  400  determines that the RAM  200  maintains the low electric power mode while the system power supply is turned off (S 320 ). Depending on the determination, the central processing unit  400  performs the following warm booting process (S 330 ,  5340  and S 350 ). 
     The central processing unit  400  examines an error of the booting data previously loaded in the RAM  200  (S 330 ). The central processing unit  400  determines whether there is an error in the booting data (S 340 ), and boots the system by referring to the booting data previously loaded in the RAM  200  if there is no error (S 350 ). 
     On the contrary, if it is determined that there is an error, the central processing unit  400  performs the cold booting process (S 370  and  380 ). Subordinate processes of the cold booting process (S 370  and  380 ) will be described later. 
     In operation  5310  of determining whether the “high” signal is input to the GPIO pin  410  or not, if a “low” signal is input, the central processing unit  400  determines that the RAM  200  does not maintain the low electric power mode (S 360 ). Accordingly, the central process unit  400  performs the following cold booting process (S 370  and S 380 ). 
     The central processing unit  400  loads the booting data stored in the storing unit  100  in the RAM  200  from the storing unit  100  (S 370 ). Then, the central processing unit  400  performs the system booting by referring to the booting data loaded in the RAM  200  (S 380 ). 
     In this manner, the central processing unit  400  may reduce the system booting time by the warm booting process, and may perform the cold booting process if it is difficult to perform the warm booting. 
     Then, a control method of the control unit  500  in case of turning off the system power supply will be described.  FIG. 5  is a flowchart illustrating this process according to an exemplary embodiment. 
     As shown in  FIG. 5 , in an initial state that the system power supply is turned on, the control unit  500  receives a command of turning off the system power supply (S 400 ). 
     The control unit  500  determines whether the booting data is loaded in the RAM  200  by the central processing unit  400  (S 410 ). If the booting data is not loaded in the RAM  200 , the control unit  500  is on a standby state until loading the booting data is completed (S 420 ). 
     If it is determined that the booting data is loaded in the RAM  200 , the control unit  500  applies a “low” signal to the clock enable input pin  210  of the RAM  200  (S 430 ). Then, the control unit  500  transmits a command for operating in the low electric power mode, for example, the self refresh mode, to the RAM  200  (S 440 ). Accordingly, the RAM  200  enters the low electric power mode. 
     The control unit  500  determines whether the RAM  200  enters the low electric power mode or not (S 450 ), and turns off the system power supply (S 460 ) if it is determined that the RAM has entered the low electric power mode (S 460 ). Although the system power supply is turned off, and electric power supply to the central processing unit  400  is cut off, the storing unit  100  and the RAM  200  operate in the low electric power mode (S 470 ). Accordingly, the booting data loaded in the RAM  200  can be maintained. 
     Then, a control method of the control unit  500  in case of turning on the system power supply while the system power supply is turned off will be described.  FIG. 6  is a flowchart illustrating this process according to an exemplary embodiment. 
     As shown in  FIG. 6 , the system power supply is turned off (S 500 ), and the RAM  200  operates in the low electric power mode. The control unit  500  monitors whether the RAM  200  maintains the low electric power mode or not while the system power supply is turned off (S 510 ). 
     If the system power supply is turned on (S 520 ), the control unit  500  determines the monitoring result whether the RAM  200  maintains the low electric power mode while the system power supply is turned off (S 530 ). 
     If the RAM  200  maintains the low electric power mode, the control unit  500  applies the “high” signal to the GPIO pin  410  of the central processing unit  400  (S 540 ). On the contrary, if the RAM  200  does not maintain the low electric power mode, the control unit  500  applies the low signal to the GPIO pin  410 . 
     Accordingly, the central processing unit  400  selects the warm booting or cold booting processes to perform the system booting. 
     Although a few exemplary embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.