Abstract:
A process for a monitor working in a DPMS mode applies when a monitor ends a working mode and enters the DPMS mode. In the DPMS mode, when the signal processor of the monitor detects there is no signal input to the connecting interface, the signal processor will be off and inform the micro-controller to open the signal detecting function to find whether there is a signal input to the connecting interface. When the micro-controller detects there is no signal input for a certain of time, the micro-controller will enter the sleep status. As a result, the purpose of saving the electricity can be achieved.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The invention relates to a process for reducing a monitor&#39;s power consuming, and more particularly, to a process for reducing the power consuming of a monitor which works in a DPMS mode. 
     2. Related Art 
     Presently, a monitor has to meet the requirements of Energy Star established by the U.S. Environmental Protection Agency and the Display Power Management Standard (DPMS) established by the Video Electronics Standards Association (VESA) to be qualified as an energy saving monitor. The DPMS provides a power management function for the monitor, which will process an energy saving mode when there is no signal input to the monitor so the electricity can be saved. 
     There are four modes in the power management for a monitor, which are normal, standby, DPMS and off. As shown in Table 1, these four modes correspond to different status of signal processor and micro-controller of the monitor and different power consuming extents respectively. 
     
       
         
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Signal processor 
                 Micro-controller 
                 Power consuming 
               
               
                   
               
             
             
               
                 Normal 
                 On 
                 On 
                 High 
               
               
                 Standby 
                 Off 
                 Sleep 
                 Low 
               
               
                 DPMS 
                 Sleep 
                 On 
                 Medium 
               
               
                 Off 
                 Off 
                 Sleep 
                 Low 
               
               
                   
               
             
          
         
       
     
     The normal mode is when the monitor displays. A monitor like a liquid crystal display usually has different status in its normal mode, such as a television mode and a computer mode, which have different signal sources respectively. The Off mode is when all the signal sources are closed; therefore the signal processor which is responsible for detecting the signal will also be off to save the energy. In addition, when the monitor switched from one mode to another, the monitor must switch the signal source. In this switching process, the monitor is in the DPMS mode. At this time, the monitor will try to detect the signal source. While there is no signal detected, there is no display in the monitor. But when there is a signal detected, the monitor will be in the switched mode and display. 
     In the prior art, the signal processor is used for detecting the signal. Therefore in the DPMS mode, the signal processor is in the sleep status. However, in order to accelerate the image output when a signal is detected, the micro-controller must be on so the monitor will certainly consume some energy. If the signal processor does not detect a signal for certain of time, the energy consuming in the DPMS mode will be tremendous. Therefore, how to reduce the energy consuming in the DPMS mode becomes a problem. 
     SUMMARY 
     According to the foregoing problems, the invention provides a process for a monitor to operate in a DPMS mode, which uses a logic gate to co-operate with the micro-controller to allow the monitor have a similar power consuming efficiency in the DPMS mode and the standby mode. 
     An illustrative embodiment of the process includes the following steps. In the DPMS mode, the signal processor first detects whether there is a signal input to the connecting interface. When there is no signal input, the signal processor informs the micro-controller to start the signal detecting function to detect the signal input of the connecting interface, processes the shut down procedure to be off and informs the micro-processor its status. The micro-controller opens the signal detecting function to detect whether there is a signal input to the connecting interface. The micro-controller checks whether the pin which connects the logic gate to the micro-controller has a potential change to determine whether there is a signal input to the connecting interface. If there is no potential change, the micro-controller will check whether the potential of the pin doesn&#39;t change for a certain time. If the pin doesn&#39;t have the potential change for a certain time, the micro-controller will be in the sleep mode and wait for the potential change of the pin. 
     According to the description above, the technique of the invention is when the monitor is in the DPMS mode and there is no signal input, the signal processor will be off and the micro-controller will be used instead to detect whether there is a signal input to the connecting interface. After certain of time while no signal input is detected, the micro-controller will be in the sleep mode so the purpose of saving the electricity can be achieved. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description given below, which is for illustration only and thus is not limitative of the present invention, wherein: 
         FIG. 1  is a block diagram of a monitor according to the invention; 
         FIG. 2A  shows a part of process of a monitor working in a DPMS mode of the invention; and 
         FIG. 2B  shows a part of process of a monitor working in a DPMS mode of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     The invention supports four types of energy management modes for a monitor, such as normal, standby, DPMS and off. The technique of the invention is to change the action of the monitor in the DPMS mode to reduce the energy consuming. 
     Please refer to  FIG. 1  of a block diagram of a monitor  10  according to the invention. As shown in  FIG. 1 , the monitor  10  includes a connecting interface  101 , a logic gate  102 , a micro-controller  103 , and a signal processor  104 . The connecting interface  101  couples to the logic gate  102  and the signal processor  104 , the micro-controller  103  couples to the logic gate  102  and the signal processor  104  and at least one electric signal will transmit between the coupled devices. 
     In the invention, the micro-controller  103  is used in the DPMS mode to replace the signal processor  104  to detect whether there is a signal input to the connecting interface  101  in order to save the energy.  FIGS. 2A and 2B  show the processes of the monitor  10  in the DPMS mode. When a user switches the monitor  10  from a first working mode to a second working mode in the normal mode at the beginning (step  201 ), the monitor  10  will end the first working mode and then enter the DPMS mode (step  202 ). In the DPMS mode, the signal processor  104  will detect the signal source of the second working mode first, where it will detect whether there is a signal input to the connecting interface  101  (step  203 ). If there is a signal input, the monitor  10  will end the DPMS mode and enter the second working mode, and the signal processor  104  will process the image display in the second working mode (step  204 ). Following the step  203 , if there is no signal input, the signal processor  104  will inform the micro-controller  103  to open the signal detecting function to detect the signal input of the connecting interface  101  (step  205 ), and the signal processor  104  will carry on the turn off procedure to be off and inform the micro-controller  103  to be off too (step  206 ). Following the step  206 , the micro-controller  103  opens the signal detecting function to detect whether the signal source of the second working mode, which is also the connecting interface has a signal input (step  207 ). The invention uses the logic gate  102  to connect the micro-controller  103  and the connecting interface  101 . The micro-controller  103  will check whether the pin which connects the logic gate  102  to the micro-controller  103  has a potential change to determine whether there is a signal input to the connecting interface  101  (step  208 ). If there is a potential change, the micro-controller  103  will check whether the frequency of the potential change has reached a predetermined value (step  209 ). If the frequency of the potential change has reached the predetermined value, the micro-controller  103  will open the signal processor  104  to process the step  203  (step  210 ). Following the step  209 , if the frequency of the potential change does not reach the predetermined value, the step  208  will then proceed. Following the step  208 , if there is no potential change, the micro-controller  103  will check Whether the pin has no potential change for a predetermined time (step  211 ). If the pin has no potential change during the predetermined time, the micro-controller  103  will then be in the sleep status and wait the pin has a potential change (step  212 ). Following the step  211 , if the pin has a potential change during the predetermined time, then the step  208  will proceed. 
     According to one preferred embodiment of the invention, the monitor  10  can be a display, such as a liquid crystal television, where its first working mode can be a television mode and its second working mode can be a computer mode. The signal source of the second working mode is the connecting interface  101 , which can be a D-sub port, a digital visual interface (DVI), a high-definition multimedia interface (HDMI) or a unified display interface (UDI). 
     Using the D-sub port as an example in this embodiment, the signal lines are connected from the tenth, eleventh, thirteenth and fourteenth pins of the D-sub port to the pins of the logic gate  102  and the signal processor  104 , where the tenth and eleventh pins are used for ground connection of the H-sync signal and the V-sync signal respectively, and the thirteenth and fourteenth pins are used for transmitting the H-sync signal and the V-sync signal respectively. In this embodiment, the logic gate  102  connects to the general purpose input/output pin of the micro-controller  103  and outputs the signal to it. If the general purpose input/output pin is low potential enabled, the logic gate  102  can be a NOR type logic gate. That is, when there is no signal input to the D-sub port and the thirteenth and fourteenth pin are low potential, the general purpose input/output pin of the micro-controller  103  which connects to the NOR type logic gate  102  will be high potential. On the other hand, when there is a signal input to the D-sub port, the thirteenth and fourteenth pins will be high potential and the NOR type logic gate will be low potential so the micro-controller  103  will be enabled. 
     When a user switches the monitor  10  from the television mode to the computer mode (similar to step  201 ) at the beginning, the monitor  10  will end the television mode and then enter the DPMS mode (similar to step  202 ). In the DPMS mode, the signal processor  104  will detect whether the D-sub port has an H-sync and a V-sync signal input, that is, whether there is a potential change to the pin which connects the D-sub port to the signal processor  104  (similar to step  203 ). If the signal processor detects there is an H-sync and a V-sync signal input, the monitor  10  will end the DPMS mode and enter the second working mode, and the signal processor  104  will process the image display of the computer mode (similar to step  204 ). If the signal processor detects there is no signal input, the signal processor  104  will inform the micro-controller  103  to open the signal detecting function to detect the signal input of the D-sub port (similar to step  205 ). 
     The signal processor  104  will then carry on the turn off procedure to be off and inform the micro-controller  103  to be off too (similar to step  206 ). The micro-controller  103  will open the signal detecting functions to detect whether the D-sub port has a signal input through the output of the NOR type logic gate (similar to step  207 ). The micro-controller  103  will check whether the pin which connects the NOR type logic gate to the micro-controller  103  has a potential change (similar to step  208 ). If the NOR type logic gate outputs a low potential, which means the D-sub port has an H-sync signal and a V-sync signal input, then the micro-controller  103  will check whether the frequency of the potential change has reached a predetermined value (similar to step  209 ). If the frequency of the potential change has reached the predetermined value, the micro-controller  103  will open the signal processor  104  to process the step  203  (similar to step  210 ). Following the step  209 , if the frequency of the potential change does not reach the predetermined value, the step  208  will then proceed. Following the step  208 , if there is no potential change, the micro-controller  103  will check whether the pin has no potential change for a predetermined time (similar to step  211 ). If the pin has no potential change during the predetermined time, the micro-controller  103  will then switch from the working status to the sleep status and wait for the pin having a potential change (similar to step  212 ). Following the step  211 , if the pin has a potential change during the predetermined time, then the step  208  will proceed. 
     While the preferred embodiments of the invention have been set forth for the purpose of disclosure, modifications of the disclosed embodiments of the invention as well as other embodiments thereof may occur to those skilled in the art. Accordingly, the appended claims are intended to cover all embodiments, which do not depart from the spirit and scope of the invention.