Method for detecting and separating vertical and horizonal synchronous signals from computer system

Abstract

A method for detecting and separating vertical and horizontal synchronous signals from a computer system. The input forms of the vertical and horizontal synchronous signals from the computer system are detected by scanning a vertical synchronous signal terminal, a horizontal/composite synchronous signal terminal and a synchronous-on-green terminal of the computer system. In accordance with the detected input forms, the vertical and horizontal synchronous signals are separated from each other and then adjusted in polarity. Therefore, the present invention requires no separate hardware for the separation and polarity adjustment of the vertical and horizontal synchronous signals, resulting in simplification in circuit construction and reductions in number of used components and size of a printed circuit board.

1. A method for detecting and separating vertical and horizontal synchronous signals received by a monitor from a computer, comprising the steps of:
 a checking for inputs from a vertical synchronous signal terminal, a horizontal/composite synchronous signal terminal and a synchronous-on-green terminal of said computer to detect input forms of the vertical and horizontal synchronous signals from said computer;    generating reference vertical and horizontal synchronous signals when no input is detected during said step of checking for inputs from said vertical synchronous signal terminal, said horizontal/composite synchronous signal terminal and said synchronous-on-green terminal of said computer;    performing synchronous signal separation in accordance with the input forms detected during said step of checking, and    adjusting polarities of the separated vertical and horizontal synchronous signals.    
     
     
       2. A method for detecting vertical and horizontal synchronous signals received by a monitor from a computer, comprising the steps of:
 checking a horizontal/composite synchronous signal terminal to determine whether the horizontal synchronous signal is input;  
 checking a vertical synchronous terminal to determine whether the vertical synchronous signal is input, when it is determined that the horizontal synchronous signal is not input from said horizontal/composite synchronous signals terminal;  
 checking a synchronous-on-green terminal to determine whether said horizontal synchronous signal is input, when it is determined that the vertical synchronous signal is not input from said vertical synchronous signal terminal; and  
 making a determination that no synchronous signal has been input, generating reference vertical and horizontal synchronous signals and returning to said step of checking said horizontal/composite synchronous signal terminal, when it is determined that the horizontal synchronous signal is not input from said synchronous-on-green terminal.  
 
     
     
       3. The method as set forth in  claim 2 , further comprising the steps of:
 checking said vertical synchronous signal terminal to determine whether the vertical synchronous signal is input, when it is determined that the horizontal synchronous signal is input from said horizontal/composite synchronous signal terminal;  
 determining whether said horizontal synchronous signal has a positive polarity or a negative polarity, when it is determined that the horizontal synchronous signal is input from said horizontal/composite synchronous signal terminal and the vertical synchronous signal is not input from said vertical synchronous signal terminal;  
 setting the polarity of said horizontal synchronous signal to positive and beginning a vertical synchronous signal extraction mode, when it is determined that said horizontal synchronous signal has a positive polarity;  
 checking said horizontal/composite synchronous signal terminal to determine whether the vertical synchronous signal is input;  
 making a determination that only the horizontal synchronous signal is input from said horizontal/composite synchronous signal terminal and performing a corresponding synchronous signal separation process, when it is determined that said vertical synchronous signal is not input from said horizontal/composite synchronous signal terminal; and  
 making a determination that a composite synchronous signal is input from said horizontal/composite synchronous signal terminal, that the polarity of said horizontal and vertical synchronous signals are both positive and performing a corresponding synchronous signal separation process, when it is determined that said vertical synchronous signal is input from said horizontal/composite synchronous signal terminal.  
 
     
     
       4. The method as set forth in  claim 3 , further comprising the steps of:
 setting the polarity of said horizontal synchronous signal to negative and beginning a vertical synchronous signal extraction mode, when it is determined that said horizontal synchronous signal has a negative polarity;  
 checking said horizontal/composite synchronous signal terminal to determine whether the vertical synchronous signal is input;  
 making a determination that only the horizontal synchronous signal is input from said horizontal/composite synchronous signal terminal and performing a corresponding synchronous signal separation process, when it is determined that said vertical synchronous signal is not input from said horizontal/composite synchronous signal terminal; and  
 making a determination that a composite synchronous signal is input from said horizontal/composite synchronous signal terminal, that the polarity of said horizontal and vertical synchronous signals are both negative and performing a corresponding synchronous signal separation process, when it is determined that said vertical synchronous signal is input from said horizontal/composite synchronous signal terminal.  
 
     
     
       5. The method as set forth in  claim 3 , further comprising the steps of:
 determining whether said horizontal synchronous signal has a positive polarity or a negative polarity, when it is determined that the horizontal synchronous signal is input from said horizontal/composite synchronous signal terminal and the vertical synchronous signal is input from said vertical synchronous signal terminal;  
 setting the polarity of said horizontal synchronous signal to positive and beginning a vertical synchronous signal extraction mode, when it is determined that said horizontal synchronous signal has a positive polarity;  
 checking said horizontal/composite synchronous signal terminal to determine whether the vertical synchronous signal is input; and  
 making a determination that a composite synchronous signal is input from said horizontal/composite synchronous signal terminal, that the polarity of said horizontal and vertical synchronous signals are both positive and performing a corresponding synchronous signal separation process, when it is determined that said vertical synchronous signal is input from said horizontal/composite synchronous signal terminal.  
 
     
     
       6. The method as set forth in  claim 5 , further comprising the steps of:
 determining whether said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity or a negative polarity, when it is determined that said vertical synchronous signal is not input from said horizontal/composite synchronous signal terminal;  
 making a determination that separate horizontal and vertical synchronous signal are input, that said horizontal and vertical synchronous signals have a positive polarity and performing a corresponding synchronous signal separation process, when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity; and  
 making a determination that separate horizontal and vertical synchronous signals are input, that said horizontal synchronous signal has a positive polarity, that said vertical synchronous signal has a negative polarity and performing a corresponding synchronous signal separation process, when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a negative polarity.  
 
     
     
       7. The method as set forth in  claim 5 , further comprising the steps of:
 setting the polarity of said horizontal synchronous signal to negative and beginning a vertical synchronous signal extraction mode, when it is determined that said horizontal synchronous signal has a negative polarity,  
 checking said horizontal/composite synchronous signal terminal to determine whether the vertical synchronous signal is input; and  
 making a determination that a composite synchronous signal is input from said horizontal/composite synchronous signal terminal, that the polarity of said horizontal and vertical synchronous signals are both negative and performing a corresponding synchronous signal separation process, when it is determined that said vertical synchronous signal is input from said horizontal/composite synchronous signal terminal.  
 
     
     
       8. The method as set forth in  claim 7 , further comprising the steps of:
 determining whether said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity or a negative polarity, when it is determined that said vertical synchronous signal is not input from said horizontal/composite synchronous signal terminal;  
 making a determination that separate horizontal and vertical synchronous signals are input, that said horizontal synchronous signal has a negative polarity, that said vertical synchronous signals has a positive polarity and performing a corresponding synchronous signal separation process, when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity; and  
 making a determination that separate horizontal and vertical synchronous signals are input, that said horizontal and vertical synchronous signal have a negative polarity and performing a corresponding synchronous signal separation process, when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a negative polarity.  
 
     
     
       9. The method as set forth in  claim 2 , further comprising the steps of:
 making a determination that only the vertical synchronous signal has been input when it is determined that said vertical synchronous signal is input from said vertical synchronous signal terminal; and  
 performing a corresponding synchronous signal separation process.  
 
     
     
       10. The method as set forth in  claim 2 , further comprising the steps of:
 checking for input of said vertical synchronous signal from said synchronous-on-green terminal, when it is determined that said horizontal synchronous signal is input from said synchronous-on-green terminal;  
 making a determination that only the horizontal synchronous signal has been input from said synchronous-on-green terminal and performing a corresponding synchronous separation process, when it is determined that said vertical synchronous signal is not input from said synchronous-on-green terminal; and  
 making a determination that the vertical and horizontal synchronous signals are input from said synchronous-on-green terminal, setting the polarity of said vertical and horizontal synchronous signals to positive and performing a corresponding synchronous signal separation process, when it is determined that said vertical synchronous signal is input from said synchronous-on-green terminal.  
 
     
     
       11. The method as set forth in  claim 3 , wherein said step of making a determination that only the horizontal synchronous signal is input from said horizontal/composite synchronous signal terminal and performing a corresponding synchronous signal separation process further comprises a step of clamping a front porch of the horizontal synchronous signal to a reference level. 
     
     
       12. The method as set forth in  claim 3 , wherein said step of making a determination that a composite synchronous signal is input from said horizontal/composite synchronous signal terminal, that the polarity of said horizontal and vertical synchronous signals are both positive and performing a corresponding synchronous signal separation process further comprises a step of clamping a back porch of the horizontal synchronous signal to a reference level. 
     
     
       13. The method as set forth in  claim 4 , wherein said step of making a determination that only the horizontal synchronous signal is input from said horizontal/composite synchronous signal terminal and performing a corresponding synchronous signal separation process further comprises a step of clamping a front porch of the horizontal synchronous signal to a reference level. 
     
     
       14. The method as set froth in  claim 4 , wherein said step of making a determination that a composite synchronous signal is input from said horizontal/composite synchronous signal terminal, that the polarity of said horizontal and vertical synchronous signals are both negative and performing a corresponding synchronous signal separation process further comprises a step of clamping a back porch of the horizontal synchronous signal to a reference level. 
     
     
       15. The method as set forth in  claim 5 , wherein said step of making a determination that a composite synchronous signal is input from said horizontal/composite synchronous signal terminal, that the polarity of said horizontal and vertical synchronous signals are both positive and performing a corresponding synchronous signal separation process further comprises a step of clamping a back porch of the horizontal synchronous signal to a reference level. 
     
     
       16. The method as set forth in  claim 6 , wherein said step of making a determination that separate horizontal and vertical synchronous signals are input, that said horizontal and vertical synchronous signals have a positive polarity and performing a corresponding synchronous signal separation process further comprises a step of clamping a back porch of the horizontal synchronous signal to a reference level. 
     
     
       17. The method as set forth in  claim 6 , wherein said step of making a determination that separate horizontal and vertical synchronous signals are input, that said horizontal synchronous signal has a positive polarity, that said vertical synchronous signal has a negative polarity and performing a corresponding synchronous signal separation process further comprises a step of clamping a front porch of the horizontal synchronous signal to a reference level. 
     
     
       18. The method as set forth in  claim 7 , wherein said step of making a determination that a composite synchronous signal is input from said horizontal/composite synchronous signal terminal, that the polarity of said horizontal and vertical synchronous signals are both negative and performing a corresponding synchronous signal separation process further comprises a step of clamping a back porch of the horizontal synchronous signal to a reference level. 
     
     
       19. The method as set forth in  claim 8 , wherein said step of making a determination that separate horizontal and vertical synchronous signals are input, that said horizontal synchronous signal has a negative polarity, that said vertical synchronous signals has a positive polarity and performing a corresponding synchronous signal separation process further comprises a step of clamping a front porch of the horizontal synchronous signal to a reference level. 
     
     
       20. The method as set forth in  claim 8 , wherein said step of making a determination that separate horizontal and vertical synchronous signals are input, that said horizontal and vertical synchronous signals have a negative polarity and performing a corresponding synchronous signal separation process further comprises a step of clamping a front porch of the horizontal synchronous signal to a reference level. 
     
     
       21. A method for detecting and separating vertical and horizontal synchronous signals received by a monitor from a computer, comprising the steps of:
 checking for inputs from a vertical synchronous signal terminal, a horizontal/composite synchronous signal terminal and a synchronous-on-green terminal of said computer to detect input forms of the vertical and horizontal synchronous signals from said computer;    generating reference vertical and horizontal synchronous signals when no input is detected during said step of checking for inputs from said vertical synchronous signal terminal, said horizontal/composite synchronous signal terminal and said synchronous-on-green terminal of said computer; and    performing synchronous signal separation in accordance with the input forms detected during said step of checking and adjusting polarities of the separated vertical and horizontal synchronous signals.    
     
     
       22. The method as set forth in  claim 5 , further comprising:
   determining whether said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity or a negative polarity when it is determined that said horizontal synchronous signal has a positive polarity; and        making a determination that separate horizontal and vertical synchronous signal are input, that said horizontal and vertical synchronous signals have a positive polarity; and        clamping a back porch of the horizontal synchronous signal to a reference level when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity.     
     
     
       23. The method as set forth in  claim 5 , further comprising:
   determining whether said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity or a negative polarity when it is determined that said horizontal synchronous signal has a positive polarity; and        making a determination that separate horizontal and vertical synchronous signal are input, that said horizontal synchronous signal has a positive polarity and said vertical synchronous signal has a negative polarity; and        clamping a back porch of the horizontal synchronous signal to a reference level when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a negative polarity.     
     
     
       24. The method as set forth in  claim 5 , further comprising:
   determining whether said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity or a negative polarity when it is determined that said horizontal synchronous signal has a negative polarity; and        making a determination that separate horizontal and vertical synchronous signal are input, that said horizontal synchronous signal has a negative polarity and said vertical synchronous signal has a positive polarity; and        clamping a back porch of the horizontal synchronous signal to a reference level when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity.     
     
     
       25. The method as set forth in  claim 5 , further comprising steps of:
   determining whether said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity or a negative polarity when it is determined that said horizontal synchronous signal has a negative polarity; and        making a determination that separate horizontal and vertical synchronous signal are input, that said horizontal and vertical synchronous signals have a negative polarity; and        clamping a back porch of the horizontal synchronous signal to a reference level when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a negative polarity.     
     
     
       26. An apparatus for detecting and separating horizontal and vertical synchronous signals received by a monitor from a computer, comprising:
   a microcomputer connected to a vertical synchronous signal terminal, a horizontal/composite synchronous signal terminal and a synchronous - on - green terminal of said computer to detect inputs of said horizontal and vertical synchronous signals from said computer; and        said microcomputer generating reference vertical and horizontal synchronous signals when no input is received from said vertical synchronous signal terminal, said horizontal/composite synchronous signal terminal and said synchronous - on - green terminal of said computer;       said microcomputer is further configured to adjust polarities of the separated vertical and horizontal synchronous signals, clamping a back porch portion of the horizontal synchronous signal to a predetermined reference level and outputting separated horizontal and vertical synchronous signals.     
     
     
       27. The apparatus as set forth in  claim 26 , wherein:
   said microcomputer is further configured to determine whether the vertical synchronous signal is received via the vertical synchronous signal terminal when said microcomputer detects a horizontal synchronous signal input from said horizontal/composite synchronous signal terminal;        said microcomputer is further configured to determine whether said horizontal synchronous signal has a positive polarity or a negative polarity, when it is determined that the vertical synchronous signal is input from said vertical synchronous signal terminal;        said microcomputer is further configured to determine whether said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity or a negative polarity, when it is determined that said horizontal synchronous signal has a positive polarity;        said microcomputer is further configured to make a determination that separate horizontal and vertical synchronous signal are input, that said horizontal and vertical synchronous signals have a positive polarity and clamping said back porch of the horizontal synchronous signal to the reference level, when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity; and        said microcomputer is further configured to output said separated horizontal and vertical synchronous signals after clamping the back porch of the horizontal synchronous signal to said reference level.     
     
     
       28. The apparatus as set forth in  claim 26 , wherein:
   said microcomputer is further configured to determine whether the vertical synchronous signal is received via the vertical synchronous signal terminal when said microcomputer detects a horizontal synchronous signal input from said horizontal/composite synchronous signal terminal;        said microcomputer is further configured to determine whether said horizontal synchronous signal has a positive polarity or a negative polarity, when it is determined that the vertical synchronous signal is input from said vertical synchronous signal terminal;        said microcomputer is further configured to determine whether said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity or a negative polarity, when it is determined that said horizontal synchronous signal has a positive polarity;        said microcomputer is further configured to make a determination that separate horizontal and vertical synchronous signal are input, that said horizontal synchronous signal has a positive polarity and said vertical synchronous signal has a negative polarity and clamping said back porch of the horizontal synchronous signal to the reference level, when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a negative polarity; and        said microcomputer is further configured to output said separated horizontal and vertical synchronous signals after clamping the back porch of the horizontal synchronous signal to said reference level.     
     
     
       29. The apparatus as set forth in  claim 26 , wherein:
   said microcomputer is further configured to determine whether said horizontal synchronous signal has a positive polarity or a negative polarity, when it is determined that the vertical synchronous signal is input from said vertical synchronous signal terminal;       said microcomputer is further configured to determine whether said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity or a negative polarity, when it is determined that said horizontal synchronous signal has a negative polarity;        said microcomputer is further configured to make a determination that separate horizontal and vertical synchronous signal are input, that said horizontal and vertical synchronous signals have a negative polarity and clamping the back porch of the horizontal synchronous signal to a reference level when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a negative polarity; and        said microcomputer is further configured to output said separated horizontal and vertical synchronous signals after clamping the back porch of the horizontal synchronous signal to said reference level.     
     
     
       30. The apparatus as set forth in  claim 26 , wherein:
   said microcomputer is further configured to determine whether said horizontal synchronous signal has a positive polarity or a negative polarity when it is determined that the vertical synchronous signal is input from said vertical synchronous signal terminal;        said microcomputer is further configured to determine whether said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity or a negative polarity, when it is determined that said horizontal synchronous signal has a negative polarity;        said microcomputer is further configured to make a determination that separate horizontal and vertical synchronous signal are input, that said horizontal synchronous signal has a negative polarity and said vertical synchronous signal has a positive polarity and clamping the back porch of the horizontal synchronous signal to the reference level when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity; and        said microcomputer is further configured to output said separated horizontal and vertical synchronous signals after clamping the back porch of the horizontal synchronous signal to said reference level.     
     
     
       31. The apparatus as set forth in  claim 26 , wherein:
   said microcomputer is further configured to check said vertical synchronous signal terminal to determine whether the vertical synchronous signal is input, when said microcomputer does not detect a horizontal synchronous signal input from said horizontal/composite synchronous signal terminal; and        said microcomputer is further configured to make a determination that only the vertical synchronous signal has been input when it is determined that said vertical synchronous signal is input from said vertical synchronous signal terminal.     
     
     
       32. The apparatus as set forth in  claim 26 , wherein:
   said microcomputer is further configured to check said vertical synchronous signal terminal to determine whether the vertical synchronous signal is input when said microcomputer does not detect a horizontal synchronous signal input from said horizontal/composite synchronous signal terminal;        said microcomputer is further configured to check for input of said horizontal synchronous signal from said synchronous - on - green terminal when it is determined that said vertical synchronous signal is not input from said vertical synchronous signal terminal;        said microcomputer is further configured to check for input of said vertical synchronous signal from said synchronous - on - green terminal when it is determined that said horizontal synchronous signal is input from said synchronous - on - green terminal;       said microcomputer is further configured to make a determination that the vertical and horizontal synchronous signals are input from said synchronous - on - green terminal, when it is determined that said vertical synchronous signal is input from said synchronous - on - green terminal; and        said microcomputer is further configured to adjust the polarities of the vertical and horizontal synchronous signals input from said synchronous - on - green terminal and then separately outputting the horizontal and vertical synchronous signals.     
     
     
       33. The apparatus as set forth in  claim 26 , wherein:
   said microcomputer is further configured to check said vertical synchronous signal terminal to determine whether the vertical synchronous signal is input when said microcomputer does not detect a horizontal synchronous signal input from said horizontal/composite synchronous signal terminal;        said microcomputer is further configured to check for input of said horizontal synchronous signal from said synchronous - on - green terminal when it is determined that said vertical synchronous signal is not input from said vertical synchronous signal terminal;        said microcomputer is further configured to check for input of said vertical synchronous signal from said synchronous - on - green terminal when it is determined that said horizontal synchronous signal is input from said synchronous - on - green terminal; and        said microcomputer is further configured to make a determination that only the horizontal synchronous signal has been input from said synchronous - on - green terminal when it is determined that said vertical synchronous signal is not input from said synchronous - on - green terminal.     
     
     
       34. An apparatus for detecting and separating horizontal and vertical synchronous signals received by a monitor from a computer, comprising:
   a microcomputer connected to a vertical synchronous signal terminal, a horizontal/composite synchronous signal terminal and a synchronous - on - green terminal of said computer to detect inputs of said horizontal and vertical synchronous signals from said computer; and        said microcomputer generating reference vertical and horizontal synchronous signals when no input is received from said vertical synchronous signal terminal, said horizontal/composite synchronous signal terminal and said synchronous - on - green terminal of said computer;        said microcomputer is further configured to adjust the polarity of the horizontal synchronous signal and clamping a front porch portion of the horizontal synchronous signal to the predetermined reference level when it determines that only said horizontal synchronous signal is received from said horizontal/composite synchronous signal terminal.     
     
     
       35. An apparatus for detecting and separating vertical and horizontal synchronous signals received by a monitor from a computer, comprising:
   a microcomputer connected to a vertical synchronous signal terminal, a horizontal/composite synchronous signal terminal and a synchronous - on - green terminal of said computer;        said microcomputer checking said horizontal/composite synchronous signal terminal to determine whether the horizontal synchronous signal is input;        said microcomputer checking said vertical synchronous signal terminal to determine whether the vertical synchronous signal is input, when it is determined that the horizontal synchronous signal is not input from said horizontal/composite synchronous signal terminal;        said microcomputer checking said synchronous - on - green terminal to determine whether said horizontal synchronous signal is input, when it is determined that the vertical synchronous signal is not input from said vertical synchronous signal terminal; and        said microcomputer making a determination that no synchronous signal has been input, generating reference vertical and horizontal synchronous signals and again checking said horizontal/composite synchronous signal terminal, when it is determined that the horizontal synchronous signal is not input from said synchronous - on - green terminal.     
     
     
       36. The apparatus as set forth in  claim 35 , wherein:
   said microcomputer is further configured to check said vertical synchronous signal terminal to determine whether the vertical synchronous signal is input when it is determined that the horizontal synchronous signal is input from said horizontal/composite synchronous signal terminal and to determine whether said horizontal synchronous signal has a positive polarity or a negative polarity when it is determined that the horizontal synchronous signal is input from said horizontal/composite synchronous signal terminal and the vertical synchronous signal is not input from said vertical synchronous signal terminal and to set the polarity of said horizontal synchronous signal to positive when it is determined that said horizontal synchronous signal has a positive polarity.     
     
     
       37. The apparatus as set forth in  claim 36 , wherein:
   said microcomputer is further configured to set the polarity of said horizontal synchronous signal to negative, when it is determined that said horizontal synchronous signal has a negative polarity;        said microcomputer is further configured to check said horizontal/composite synchronous signal terminal to determine whether the vertical synchronous signal is input, after setting the polarity of said horizontal synchronous signal to negative;        said microcomputer is further configured to make a determination that only the horizontal synchronous signal is input from said horizontal/composite synchronous signal terminal and clamping a front porch of the horizontal synchronous signal to a reference level when it is determined that said vertical synchronous signal is not input from said horizontal/composite synchronous signal terminal; and        said microcomputer is further configured to make a determination that a composite synchronous signal is input from said horizontal/composite synchronous signal terminal, that the polarity of said horizontal and vertical synchronous signals are both negative and clamping a back porch of the horizontal synchronous signal to a reference level when it is determined that said vertical synchronous signal is input from said horizontal/composite synchronous signal terminal.     
     
     
       38. The apparatus as set forth in  claim 36 , wherein:
   said microcomputer is further configured to determine whether said horizontal synchronous signal has a positive polarity or a negative polarity, when it is determined that the vertical synchronous signal is input from said vertical synchronous signal terminal;        said microcomputer is further configured to determine whether said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity or a negative polarity, when it is determined that said horizontal synchronous signal has a positive polarity; and        said microcomputer is further configured to make a determination that separate horizontal and vertical synchronous signal are input, that said horizontal and vertical synchronous signals have a positive polarity and clamping a back porch of the horizontal synchronous signal to a reference level when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity.     
     
     
       39. The apparatus as set forth in  claim 38 , wherein:
   said microcomputer is further configured to make a determination that separate horizontal and vertical synchronous signal are input, that said horizontal synchronous signal has a positive polarity and said vertical synchronous signal has a negative polarity and clamping a back porch of the horizontal synchronous signal to a reference level when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a negative polarity.     
     
     
       40. The apparatus as set forth in  claim 36 , wherein:
   said microcomputer is configured to determine whether said horizontal synchronous signal has a positive polarity or a negative polarity, when it is determined that the vertical synchronous signal is input from said vertical synchronous signal terminal;        said microcomputer is configured to determine whether said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity or a negative polarity, when it is determined that said horizontal synchronous signal has a negative polarity; and        said microcomputer is configured to make a determination that separate horizontal and vertical synchronous signal are input, that said horizontal and vertical synchronous signals have a negative polarity and clamping a back porch of the horizontal synchronous signal to a reference level when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a negative polarity.     
     
     
       41. The apparatus as set forth in  claim 40 , wherein:
   said microcomputer is further configured to make a determination that separate horizontal and vertical synchronous signal are input, that said horizontal synchronous signal has a negative polarity and said vertical synchronous signal has a positive polarity and clamping a back porch of the horizontal synchronous signal to a reference level, when it is determined that said vertical synchronous signal from said vertical synchronous signal terminal has a positive polarity.     
     
     
       42. The apparatus as set forth in  claim 40 , wherein:
   said microcomputer is further configured to check for input of said vertical synchronous signal from said synchronous - on - green terminal when it is determined that said horizontal synchronous signal is input from said synchronous - on - green terminal;        said microcomputer is further configured to make a determination that olly the horizontal synchronous signal has been input from said synchronous - on - green terminal, when it is determined that said vertical synchronous signal is not input from said synchronous - on - green terminal; and        said microcomputer is further configured to make a determination that the vertical and horizontal synchronous signals are input from said synchronous - on - green terminal, when it is determined that said vertical synchronous signal is input from said synchronous - on - green terminal, and then setting the polarity of the vertical and horizontal synchronous signal to positive.     
     
     
       43. The apparatus as set forth in  claim 35 , wherein:
   said microcomputer is further configured to check said horizontal/composite synchronous signal terminal to determine whether the vertical synchronous signal is input, after setting the polarity of said horizontal synchronous signal to positive and to make a determination that only the horizontal synchronous signal is input from said horizontal/composite synchronous signal terminal and clamping a front porch of the horizontal synchronous signal to a reference level, when it is determined that said vertical synchronous signal is not input from said horizontal/composite synchronous signal terminal.     
     
     
       44. The apparatus as set forth in cain  43 , wherein:
   said microcomputer is further configured to make a determination that a composite synchronous signal is input from said horizontal/composite synchronous signal terminal, that the polarity of said horizontal and vertical synchronous signals are both positive and clamping a back porch of the horizontal synchronous signal to a reference level, when it is determined that said vertical synchronous signal is input from said horizontal/composite synchronous signal terminal.     
     
     
       45. The apparatus as set forth in  claim 35 , wherein:
   said microcomputer is further configured to make a determination that only the vertical synchronous signal has been input when it is determined that said vertical synchronous signal is input from said vertical synchronous signal terminal.     
     
     
       46. A storage medium having stored thereon a set of instructions implementing a method for detecting and separating horizontal and vertical synchronous signals received by a monitor from a computer, said set of instruction comprising one or more instructions for:
   generating reference vertical and horizontal synchronous signals when no vertical nor horizontal synchronous signals from said computer are detected while checking a vertical synchronous signal terminal, a horizontal/composite synchronous signal terminal and a synchronous - on - green terminal of said computer for said vertical and horizontal synchronous signals;        determining whether a composite synchronous signal is received when the horizontal synchronous signal is detected at said horizontal/composite synchronous signal terminal; adjusting polarities of the vertical and horizontal synchronous signals, when it is determined that said composite synchronous signal is received;        clamping a back porch portion of the horizontal synchronous signal to a predetermined reference level; and        outputting separated horizontal and vertical synchronous signals.     
     
     
       47. The storage medium as set forth in  claim 46 , said set of instructions further comprising further one or more instructions for:
   adjusting the polarity of the horizontal synchronous signal and clamping a front porch portion of the horizontal synchronous signal to the predetermined reference level when it is determined that only said horizontal synchronous signal is input from said horizontal/composite synchronous signal terminal.     
     
     
       48. The storage medium as set forth in  claim 46 , said set of instructions further comprising one or more instructions for:
   determining whether the vertical synchronous signal is received via the vertical synchronous signal terminal when it is determined that the horizontal synchronous signal is detected at said horizontal/composite synchronous signal terminal;        determining whether said horizontal synchronous signal has a positive polarity or a negative polarity, when it is determined that the vertical synchronous signal is received via said vertical synchronous signal terminal;        determining whether said vertical synchronous signal received via said vertical synchronous signal terminal has a positive polarity or a negative polarity, when it is determined that said horizontal synchronous signal has a positive polarity;        making a determination that separate horizontal and vertical synchronous signal are input, that said horizontal and vertical synchronous signals have a positive polarity and clamping a back porch of the horizontal synchronous signal to the reference level, when it is determined that said vertical synchronous signal received via said vertical synchronous signal terminal has a positive polarity; and        outputting the separate horizontal and vertical synchronous signals after clamping the back porch of the horizontal synchronous signal to said reference level.     
     
     
       49. The storage medium as set forth in  claim 46 , said set of instructions further comprising one or more instructions for:
   determining whether the vertical synchronous signal is received via the vertical synchronous signal terminal when the horizontal synchronous signal is detected at said horizontal/composite synchronous signal terminal;        determining whether said horizontal synchronous signal has a positive polarity or a negative polarity, when it is determined that the vertical synchronous signal is received via said vertical synchronous signal terminal;       determining whether said vertical synchronous signal received via said vertical synchronous signal terminal has a positive polarity or a negative polarity, when it is determined that said horizontal synchronous signal has a positive polarity;        making a determination that separate horizontal and vertical synchronous signal are input, that said horizontal synchronous signal has as positive polarity and said vertical synchronous signal has a negative polarity and clamping a back porch of the horizontal synchronous signal to the reference level, when it is determined that said vertical synchronous signal received via said vertical synchronous signal terminal has a negative polarity; and        outputting the separate horizontal and vertical synchronous signals after clamping the back porch of the horizontal synchronous signal to said reference level.     
     
     
       50. The storage medium as set forth in  claim 46 , said set of instructions further comprising one or more instructions for:
   determining whether said horizontal synchronous signal has a positive polarity or a negative polarity, when it is determined that the vertical synchronous signal is received via said vertical synchronous signal terminal;        determining whether said vertical synchronous signal received via said vertical synchronous signal terminal has a positive polarity or a negative polarity, when it is determined that said horizontal synchronous signal has a negative polarity;        making a determination that separate horizontal and vertical synchronous signal are input, that said horizontal and vertical synchronous signals have a negative polarity and clamping a back porch of the horizontal synchronous signal to a reference level, when it is determined that said vertical synchronous signal received via said vertical synchronous signal terminal has a negative polarity; and        outputting the separate horizontal and vertical synchronous signals after clamping the back porch of the horizontal synchronous signal to said reference level.     
     
     
       51. The storage medium as set forth in  claim 46 , said set of instructions further comprising one or more instructions for:
   determining whether said horizontal synchronous signal has a positive polarity or a negative polarity, when it is determined that the vertical synchronous signal is received via said vertical synchronous signal terminal;        determining whether said vertical synchronous signal received via said vertical synchronous signal terminal has a positive polarity or a negative polarity, when it is determined that said horizontal synchronous signal has a negative polarity;        making a determination that separate horizontal and vertical synchronous signal are input, that said horizontal synchronous signal has a negative polarity and said vertical synchronous signal has a positive polarity and clamping a back porch of the horizontal synchronous signal to a reference level, when it is determined that said vertical synchronous signal received via said vertical synchronous signal terminal has a positive polarity; and        outputting the separate horizontal and vertical synchronous signals after clamping the back porch of the horizontal synchronous signal to said reference level.     
     
     
       52. The storage medium as set forth in  claim 46 , said set of instructions further comprising one or more instructions for:
   checking said vertical synchronous signal terminal to determine whether the vertical synchronous signal is input, when the horizontal synchronous signal is not detected at said horizontal/composite synchronous signal terminal; and        making a determination that only the vertical synchronous signal has been input when it is determined that said vertical synchronous signal is input from said vertical synchronous signal terminal.     
     
     
       53. The storage medium as set forth in  claim 46 , said set of instructions future comprising one or more instructions for:
   checking said vertical synchronous signal terminal to determine whether the vertical synchronous signal is input, when the horizontal synchronous signal is not detected at said horizontal/composite synchronous signal terminal;        checking for input of said horizontal synchronous signal from said synchronous - on - green terminal, when it is determined that said vertical synchronous signal is not input from said vertical synchronous signal terminal;        checking for input of said vertical synchronous signal from said synchronous - on - green terminal, when it is determined that said horizontal synchronous signal is input from said synchronous - on - green terminal;        making a determination that the vertical and horizontal synchronous signals are input from said synchronous - on - green terminal, when it is determined that said vertical synchronous signal is input from said synchronous - on - green terminal; and        adjusting polarities of the vertical and horizontal synchronous signals input from said synchronous - on - green terminal and then separately outputting the horizontal and vertical synchronous signals.     
     
     
       54. The storage medium as set forth in  claim 46 , said set of instructions further comprising one or more instructions for:
   checking said vertical synchronous signal terminal to determine whether the vertical synchronous signal is input, when the horizontal synchronous signal is not detected at said horizontal/composite synchronous signal terminal;        checking for input of said horizontal synchronous signal from said synchronous - on - green terminal, when it is determined that said vertical synchronous signal is not input from said vertical synchronous signal terminal;        checking for input of said vertical synchronous signal from said synchronous - on - green terminal, when it is determined that said horizontal synchronous signal is input from said synchronous - on - green terminal; and making a determination that only the horizontal synchronous signal has been input from said synchronous - on - green terminal, when it is determined that said vertical synchronous signal is not input from said synchronous - on - green terminal.