Patent Publication Number: US-2006007225-A1

Title: Display apparatus and control method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims the benefit of Korean Patent Application No. 200449147, filed Jun. 28, 2004, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety and by reference.  
     BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present general inventive concept relates to a display apparatus comprising a main body, a power key provided in the main body to turn on/off power, and a display to display an image thereon, and more particularly, to a display apparatus and control method thereof to prevent a user from being confused as to whether the power key is input to the display apparatus in a power off mode or in an automatic off mode, and to thereby be simply operated by the user.  
      2. Description of the Related Art  
      Generally, a conventional display apparatus has a main body, a power key provided in the main body to turn on/off power, and a display displaying an image, and goes into a power-on state by supplying power to circuits in the display apparatus if the power key is input when the display apparatus is in a power off state. Accordingly, the display apparatus displays an image on a screen in the display by processing an image signal input from an external device. Further, the display apparatus turns off the power by cutting off the power supplied to the circuits in the display apparatus if the power key is input thereto when the display apparatus is in the power on state.  
      The display apparatus displays an abnormal warning message to inform that an abnormal image signal is input thereto, if an image signal input from the external device is abnormal when the display apparatus is in the power on state. After a predetermined amount of time passes, the display apparatus eliminates the abnormal warning message and is converted into an automatic off mode to reduce power consumption by cutting off the power supplied to the circuits therein. Thereafter, when a normal image signal is input in the automatic off mode, the display apparatus supplies the power to the circuits therein and displays the image according to the image signal on the screen of the display.  
      However, when a conventional display apparatus is converted into the automatic off mode according to the input of the abnormal image signal, a user has a problem of determining whether the display apparatus is in a power off mode or in the automatic off mode by viewing the screen.  
      Accordingly, when the display apparatus is operated in the automatic off mode, the user may input the power key to turn on the power through a misunderstanding that the display apparatus is in the power off mode so that the power of the display apparatus is turned off by the inputting of the power key unrelated to the automatic off mode. Then, the user has to input the power key again so as to turn on the power because the automatic off mode was converted into the power off mode.  
      Also, the conventional display apparatus still has a problem of determining whether the display apparatus is in the power off mode or in the automatic off mode, because if the abnormal image signal is input thereto when the display apparatus is in the power on state by pushing the power key again, the conventional display apparatus is converted into the automatic off mode again.  
     SUMMARY OF THE INVENTION  
      Accordingly, the present general inventive concept provides a display apparatus and control method thereof that prevents a user from being confused as to whether the power key is input to the display apparatus in a power off mode or in an automatic off mode, and therefore is simple for the user to operate.  
      Additional aspects and advantages of the general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.  
      The foregoing and/or other aspects and advantages of the present general inventive concept are achieved by providing a display apparatus comprising a main body, a power key provided in the main body to turn on/off power, a display to display an image, a signal input part to receive an image signal from an external device, a power supply to supply the power to circuits of the display apparatus, and a controller to detect the image signal input through the signal input part, to control the power supply and the display to convert the display apparatus into an automatic off mode in which the power supplied to the circuits of the display apparatus is cut off when a normal image signal is not input thereto, to maintain the automatic off mode if the image signal input thereto is determined to be abnormal when the power key is input in the automatic off mode, and to display the image if the image signal input thereto is determined to be normal.  
      The display apparatus may further comprise an OSD (On Screen Display) generator to generate an abnormal input signal OSD message, and the controller may be converted into the automatic off mode by controlling the OSD generator to display the abnormal input signal OSD message and controlling the power supply to cut off the supplying of the power when a predetermined amount of time passes after the abnormal input signal OSD message is displayed, when the normal image signal is not input through the signal input part.  
      The controller can control the power supply and the display to display the image according to the image signal when the normal image signal is input in the automatic off mode.  
      The controller can maintain the automatic off mode by controlling the OSD generator to display the abnormal input signal OSD message when the image signal input is determined to be abnormal, and controlling the power supply to cut off the supplying of the power to the circuits when the predetermined amount of time passes after the abnormal input signal OSD message is displayed, when the power key is input thereto in the automatic off mode.  
      The foregoing and/or other aspects and advantages of the present general inventive concept may also be achieved by providing a control method of a display apparatus comprising a main body, a power key provided in the main body to turn on/off power, and a display to display an image, the control method comprising detecting whether an image signal from an external device is normal, converting the display apparatus into an automatic off mode in which supplying of power to circuits of the display apparatus is cut off when a normal image signal is not input based on the detecting of whether the image signal is normal, detecting whether the power key is input after the converting of the display apparatus into the automatic off mode, maintaining the automatic off mode when the normal image signal is not input in a case in which the power key is input, and displaying the image according to the image signal on a screen in the display and supplying the power to the circuits when the normal image signal is input when the power key is inputted.  
      The control method may further comprise providing an OSD (On Screen Display) generator, and the converting of the display apparatus into the automatic off mode may comprise displaying an abnormal input signal OSD message by controlling the OSD generator when the normal image signal is not input, and cutting off the supplying of the power to the circuits when a predetermined time passes after the input signal abnormal OSD message is displayed thereon.  
      The control method may further comprise displaying the image according to the image signal on the screen of the display and supplying the power to the circuits when the normal signal is input in the automatic off mode. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      These and other aspects and advantages of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompany drawings of which:  
       FIG. 1  is a control block diagram of a display apparatus according to an embodiment of the present general inventive concept; and  
       FIG. 2  is a control flow chart of the display apparatus of  FIG. 1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures.  
      As shown in  FIG. 1 , a display apparatus  100  may comprise a signal input part  10  to receive an image signal from an external input source  1 , a power supply  50  to supply power to circuits in the display apparatus  100 , an OSD (On Screen Display) generator  30  to generate an abnormal input signal OSD message, and a display to display an image. The display may comprise a screen  40  to display the image thereon according to the image signal, a signal processor  20  to process the image signal input from the external input source  1  to be displayable on the screen  40 , and a mixer  35  to mix the image signal output from the signal processor  20  and an OSD signal output from the OSD generator  30  to thereby output an image signal to the screen  40 . Also, the display apparatus  100  may comprise a power key  13  to turn on/off the power, an LED (Light Emitting Diode)  15  to be turned on/off so as to inform a user whether the circuits therein are supplied with power; and a microcomputer  60  to act as a controller to detect the image signal input through the signal input part  10 , to control the power supply  50  and the signal processor  20  to convert the mode of the display apparatus  100  into an automatic off mode in which the power supplied to the circuits by the power supply  50  is cut off when a normal image signal is not input to the display apparatus  100 , and in a case that the power key  13  is input in the automatic off mode, to maintain the automatic off mode when the input image signal is determined to be abnormal and to display the image on the screen  40  when the input image signal is determined to be normal.  
      The power key  13  can be provided in a main body of the display apparatus  100 , and may comprise a button part to output a signal to the microcomputer  60  by being selectively input by the user so as to turn on/off the power of the display apparatus  100 .  
      The external input source  1  inputs the image signal to the display apparatus  100  through the signal input part  10  of the display apparatus  100 , and may comprise a PC, a DVD player, or a set top box, etc.  
      The signal input part  10  is employed to receive the image signal from the external input source  1 , and may receive the image signal and an H/V sync signal, etc., by being connected to the external input source  1  through an input cable so as to receive the image signal from the external input part  1 .  
      The OSD generator  30  can generate the abnormal input signal OSD message to indicate that the image signal input to the display apparatus  100  is erred by control of the microcomputer  60 .  
      The signal processor  20  outputs the image signal after processing the image signal received from the external input source  1  to be displayable on the screen  40 . Herein, the signal processor  20  can correspondingly process the image signal according to a type of screen  40 , such as an LCD, a CRT, etc.  
      When the power key  13  is input in the power off state, the microcomputer  60  controls the power supply  50  to turn on the LED  15 , and to supply the power to the circuits of the display apparatus  100  to convert the mode of the display apparatus into the power on mode. Then, the microcomputer  60  controls the signal processor  20  to display the image on the screen  40  by processing the image signal input from the external input source  1 . When the power key  13  is input in the power on state, the microcomputer  60  turns off the power by controlling the power supply  50  to turn off the LED  15  and cut off the power supplied to the circuits in the display apparatus  100 .  
      The microcomputer  60  may store a predetermined frequency range of the H/V sync signal of the normal image signal from the external input source  1 . Accordingly, the microcomputer  60  can compare a frequency of the H/V sync signal input through the signal input part  10  in the power on state with the predetermined frequency range of the H/V sync signal. When the normal image signal is not input thereto based on the comparison of the frequency, the microcomputer  60  can control the OSD generator  30  to display an abnormal input signal OSD message to indicate that the input signal is abnormal. Also, the microcomputer  60  can control the OSD generator  30  to eliminate the abnormal input signal OSD message when a predetermined amount of time passes after the OSD message is displayed. Then, the microcomputer  60  can control the power supply  50  to turn off the LED  15 , and cut off the supplying of the power to the circuits in the display apparatus  100  to convert the mode of the display apparatus  100  into the automatic off mode.  
      When the power key  13  is input in the automatic off mode while the microcomputer  60  determines that the image signal input thereto is abnormal, the microcomputer  60  can control the OSD generator  30  to repeatedly display the abnormal input signal OSD message. Accordingly, when the predetermined amount of time passes after the abnormal input signal I OSD message is displayed, the microcomputer  60  can control the OSD generator  30  to eliminate the abnormal input signal OSD message and can control the power supply  50  to cut off the supplying of the power to the circuits of the display apparatus  100 , to thereby maintain the automatic off mode.  
      When the power key  13  is input in the automatic off mode while the microcomputer  60  determines that the image signal input thereto is normal, the microcomputer  60  can control the power supply  50  to turn on the LED  15  and to supply the power to the circuits of the display apparatus  100 . Also, the microcomputer  60  can control the signal processor  20  to display a normal image according to the image signal on the screen  40 .  
      A control method of the display apparatus of  FIG. 1 , according to an embodiment of the present general inventive concept is described while referring to  FIG. 2  as follows. First, the microcomputer  60  can determine whether the image signal input through the signal input part  10  is normal in the power on state at operation S 10 . If the microcomputer  60  determines that the image signal input thereto is abnormal, the microcomputer  60  can control the OSD generator  30  to display the abnormal input signal OSD message on the screen  40  at operation S 20 . After the abnormal input signal OSD message is displayed, the microcomputer  60  can determine whether a predetermined amount of time has passed at operation S 30 . After the predetermined amount of time passes, the microcomputer  60  can control the OSD generator to eliminate the abnormal input signal OSD message and can convert the display apparatus  100  into the automatic off mode by controlling the power supply  50  to turn off the LED  15  and cut off the supplying of the power to the circuits in the display apparatus  100  at operation S 40 . The microcomputer  60  can continuously detect whether the normal image signal is input thereto at operation S 50 . Also, the microcomputer  60  can detect whether the power key  13  is input in the automatic off mode at operation S 60 . If the microcomputer  60  detects that the power key  13  is input while the microcomputer  60  determines that the image signal input is abnormal, the microcomputer  60  can repeatedly operate from the operation S 10  to the operation S 40  in which the display apparatus  100  maintains the automatic off mode. If the microcomputer  60  determines that the normal image signal is input thereto based on the determination of the operation S 10 , the microcomputer  60  can control the signal processor  20  and the power supply  50  to display the normal image according to the image signal on the screen  40  at operation S 70 . If the microcomputer  60  determines that the normal image signal is input thereto based on the determination of the operation S 50 , the microcomputer  60  can control the signal processor  20  and the power supply  50  to display the normal image according to the image signal on the screen  40  at operation  70 .  
      Through this operation, the display apparatus  100  according to the present invention is converted into the automatic off mode according to the inputting of the abnormal image signal so that the user may simply determine whether the display apparatus is in the power off mode or the automatic off mode by viewing the screen  40 . In other words, when the user inputs the power key  13  to turn on the power through a misunderstanding that the display apparatus  100  is in the power off mode when in fact the display apparatus is in the automatic off mode, the display apparatus  100  can display the abnormal input signal OSD message according to inputting of the abnormal image signal on the screen  40  and maintain the automatic off mode. When the display apparatus  100  is in the power off mode, the display apparatus  100  can turn on the power by the inputting of the power key.  
      Accordingly, when the user inputs the power key  13  in the automatic off mode through a misunderstanding that the display apparatus  100  is in the power off mode, the abnormal input signal OSD message can be displayed on the screen  40 , so that the user may see that the display apparatus is in the automatic off mode. Also, the power supplied to the display apparatus  100  is not turned off by the inputting of the power key  13 , and the display apparatus  100  maintains the automatic off mode. Accordingly, the display apparatus  100  eliminates problems in which the user has to input the power key again so as to turn on the power, so that the power supplied to the display apparatus  100  is not turned off by the inputting of the power key  13  and the display apparatus  100  maintains the automatic off mode.  
      Although a few embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the general inventive concept, the scope of which is defined in the appended claims and their equivalents.