Video signal converting apparatus and display device having the same

Abstract

Disclosed is a video signal converting apparatus and a display device having the same which may convert a low-resolution video signal from a host into a different-resolution video signal capable of being displayed on the entire screen of a high-resolution supporting display device. The apparatus has a detector for detecting a first resolution signal indicative of a resolution of the first display signal using horizontal and vertical synchronization signals related to the first display, a comparator for comparing the first resolution signal with a second resolution signal indicative of a reference resolution; and a converter for converting the first display signal into the second resolution signal, if there is a difference between the first and the second resolution signals.

1. A liquid crystal display device for receiving horizontal and vertical synchronization signals and at least one analog video signal synchronized with said horizontal synchronization signal from a host and displays an image on a screen thereof said LCD device comprising:
 a display mode discriminating means for discriminating a display mode supported by said host in response to said horizontal and vertical synchronization signals to generate first and second mode signals and first, second, third and fourth data signals related to said discriminated display mode;    a clock generator for generating first and second pixel clock signals in synchronization with said horizontal synchronization signal, said first and second pixel clock signals having frequencies corresponding to said first and second data signals, respectively, a pulse number of said first pixel clock signal corresponding to one horizontal line being equal to a value of said first data signal and a pulse number of said second pixel clock signal corresponding to one horizontal line being equal to a value of said second data signal;    an analog-to-digital converter for converting said at least one analog video signal into a digital video signal in synchronization with said first pixel clock signal;    a memory for storing said digital video signal;    a horizontal output generator for receiving said third and fourth data signals in response to said vertical synchronization signal and generating a horizontal output signal, said digital video signal being read from said memory in synchronization with said horizontal output signal, a pixel number per one cycle of said horizontal output signal being equal to a value of said third data signal, and a pixel number per a pulse width of said horizontal output signal being equal to a value of said fourth data signal; and    a memory controller for enabling said digital video signal to be stored in said memory in accordance with said first and second mode signals, said horizontal synchronization signal and said first pixel clock signal, and enabling said digital video signal stored in said memory to be read from said memory in accordance with said second mode signal, said horizontal output signal and said second pixel clock signal.    
     
     
       2. The liquid crystal display device as set forth in  claim 1 , wherein said memory comprises:
 first, second and third memory blocks corresponding to red, green, and blue data of said digital video signal, each of said memory blocks having at least three line memories, wherein each of said line memories stores said corresponding red, green and blue data of said digital video signal from said ADC and corresponding to one horizontal line; and    first, second and third multiplexers for selectively outputting data from each of said line memories of corresponding ones of said memory blocks in response to a data selection signal from said memory controller.    
     
     
       3. The liquid crystal display device as set forth in  claim 2 , wherein said memory controller comprises:
 a flag generator for generating a plurality of write flag signals and a plurality of read flag signals;    a memory selector for generating said first and second memory selection signals for selecting said line memories in response to said write and read flag signals to block simultaneous read and write operations of a same one of said line memories; and    a memory operation control circuit for controlling write and read access to said line memories in each of said memory blocks in response to said horizontal synchronization signal, said horizontal output signal, said first memory selection signal and said first and second pixel clock signals.    
     
     
       4. The liquid crystal display device as set forth in  claim 1 , wherein said memory, said horizontal output generator and said memory controller are constituted by a single chip. 
     
     
       5. A video signal converting apparatus which is provided to convert a first display signal of serial format into a second display signal of parallel format, said apparatus comprising:
 means for detecting a first resolution signal indicative of a resolution of said first display signal using horizontal and vertical synchronization signals related to said first display signal;    means for comparing said first resolution signal with a second resolution signal indicative of a reference resolution; and    means for converting said first display signal of serial format into said second display signal of parallel format, if there is a difference between said first and said second resolution signals.    
     
     
       6. A display apparatus which receives horizontal and vertical synchronization signals, and a video signal of serial format synchronized with said horizontal synchronization signal from a host, and displays an image on a screen composed of a plurality of horizontal lines, each of said horizontal lines having a plurality of pixels, said display apparatus comprising:
 means for detecting the pixel number corresponding to said video signal from said host using said horizontal and vertical synchronization signals;    means for comparing the pixel number with a reference pixel number; and    means for sampling said video signal using a first frequency clock generated in accordance with a difference between the pixel number and the reference pixel number; and    means for displaying said sampled video signal on said screen in synchronization with a second frequency clock generated in accordance with said difference.    
     
     
       7. The display apparatus of  claim 6 , wherein said sampling means comprises a first clock generator for generating said first frequency clock synchronized with said horizontal synchronization signal in response to a first data signal from said detecting means, the pulse number of said first frequency clock corresponding to one horizontal line being equal to a value of said first data signal, and a converter for converting said video signal of serial format into a video data signal of parallel format. 
     
     
       8. The display apparatus of  claim 6 , wherein said displaying means comprises a second clock generator for generating said second frequency clock synchronized with said horizontal synchronization signal in response to said first data signal, the pulse number of said first frequency clock corresponding to one horizontal line being equal to a value of said first data signal, and a horizontal output generator for generating a horizontal output signal in response to second and third data signals from said detecting means, said sampled video signal being synchronized with said horizontal output signal. 
     
     
       9. The display apparatus of  claim 6 , further comprising a converter for converting said sampled video signal into a data signal corresponding to the number of said horizontal lines in accordance with a predetermined ratio determined by said difference between the pixel number and the reference pixel number, said data signal being provided to said displaying means. 
     
     
       10. A video signal converting method which is provided to convert a first display signal of serial format into a second display signal of parallel format, said method comprising:
 detecting a first resolution signal indicative of a resolution of said first display signal using horizontal and vertical synchronization signals related to said first display signal;    comparing said first resolution signal with a second resolution signal indicative of a reference resolution; and    converting said first display signal of serial format into said second display signal of parallel format, when said comparing step determines that there is a difference between said first and said second resolution signals.    
     
     
       11. A video signal converting method which is provided to convert a first display signal into a second display signal, said method comprising:
   detecting a first resolution signal indicative of a resolution of said first display signal;        comparing said first resolution signal with a second resolution signal indicative of a reference resolution; and        converting said first display signal having a first resolution and a first frame rate into said second display signal having a second resolution and a second frame rate if said comparing step determines that there is a difference between said first and second resolution signals,        wherein said second resolution is different from said first resolution;        wherein said second frame rate is always the same as said first frame rate; and        wherein said video signal converting method is performed in a display apparatus.     
     
     
       12. The video signal converting method of  claim 11 , wherein said detecting said first resolution signal indicative of said resolution of said first display signal is performed using horizontal and vertical synchronization signals related to said first display signal. 
     
     
       13. The video signal converting method of  claim 12 , wherein said first display signal has a serial format and said second display signal has a parallel format. 
     
     
       14. The video signal converting method of  claim 12 , wherein said first display signal comprises an analog signal and said second display signal comprises a digital signal. 
     
     
       15. The video signal converting method of  claim 11 , wherein said second resolution is a maximum resolution supported by said display apparatus. 
     
     
       16. The video signal converting method of  claim 15 , wherein said maximum resolution is  1024 × 768  pixels. 
     
     
       17. The video signal converting method of  claim 16 , wherein said first resolution is  800 × 600  pixels. 
     
     
       18. The video signal converting method of  claim 16 , wherein said first resolution is  640 × 480  pixels. 
     
     
       19. The video signal converting method of  claim 15 , wherein said reference resolution is a maximum resolution supported by said display apparatus. 
     
     
       20. The video signal converting method of  claim 19 , wherein said maximum resolution is  1024 × 768  pixels. 
     
     
       21. The video signal converting method of  claim 20 , wherein said first resolution is  800 × 600  pixels. 
     
     
       22. The video signal converting method of  claim 20 , wherein said first resolution is  640 × 480  pixels. 
     
     
       23. The video signal converting method of  claim 11 , wherein said display apparatus is a flat panel display. 
     
     
       24. The video signal converting method of  claim 23 , wherein said flat panel display is a LCD device having a screen, said screen having a predetermined resolution. 
     
     
       25. The video signal converting method of  claim 24 , wherein said second resolution corresponds to said predetermined resolution. 
     
     
       26. The video signal converting method of  claim 25 , wherein said predetermined resolution is XGA. 
     
     
       27. The video signal converting method of  claim 26 , wherein said first resolution is VGA. 
     
     
       28. The video signal converting method of  claim 26 , wherein said first resolution is SVGA. 
     
     
       29. The video signal converting method of  claim 25 , wherein said reference resolution corresponds to said predetermined resolution. 
     
     
       30. The video signal converting method of  claim 29 , wherein said first resolution, said second resolution, said reference resolution and said predetermined resolution are active resolutions. 
     
     
       31. A video signal converting method which is provided to convert a first display signal into a second display signal, said method comprising:
   detecting a first resolution signal indicative of a resolution of said first display signal, the first resolution signal being detected from a horizontal synchronization signal of the first display signal and a vertical synchronization signal of the first display signal;        comparing said first resolution signal with a second resolution signal indicative of a reference resolution; and        converting said first display signal having a first resolution and a first frame rate into said second display signal having a second resolution and a second frame rate if said comparing step determines that there is a difference between said first and second resolution signals;        wherein said second frame rate is the same as said first frame rate; and        wherein said video signal converting method is performed in a display apparatus.     
     
     
       32. The video signal converting method of  claim 31 , wherein the second frame rate is always the same as the first frame rate. 
     
     
       33. A video signal converting method which is provided to convert a first display signal into a second display signal, said method comprising:
   detecting a first resolution signal indicative of a resolution of said first display signal;        comparing said first resolution signal with a second resolution signal indicative of a reference resolution; and        converting said first display signal having a first resolution and a first frame rate into said second display signal having a second resolution and a second frame rate if said comparing step determines that there is a difference between said first and second resolution signals;        wherein said second frame rate is the same as said first frame rate;        wherein said video signal converting method is performed in a display apparatus; and        wherein said first display signal has a serial format and said second display signal has a parallel format.     
     
     
       34. The video signal converting method of  claim 33 , wherein the second frame rate is always the same as the first frame rate. 
     
     
       35. The video signal converting method of  claim 34 , wherein said detecting said first resolution signal indicative of said resolution of said first display signal is performed using horizontal and vertical synchronization signals related to said first display signal. 
     
     
       36. The video signal converting method of  claim 35 , wherein said first display signal comprises an analog signal and said second display signal comprises a digital signal. 
     
     
       37. A video signal converting method which is provided to convert a first display signal into a second display signal, said method comprising:
   detecting a first resolution signal indicative of a resolution of said first display signal;        comparing said first resolution signal with a second resolution signal indicative of a reference resolution; and        converting said first display signal having a first resolution and a first frame rate into said second display signal having a second resolution and a second frame rate if said comparing step determines that there is a difference between said first and second resolution signals;        wherein said second frame rate is the same as said first frame rate;        wherein said video signal converting method is performed in a display apparatus; and        wherein said display apparatus is an LCD flat panel display having a screen, said screen having a predetermined resolution.     
     
     
       38. The video signal converting method of  claim 37 , wherein the second frame rate is always the same as the first frame rate. 
     
     
       39. The video signal converting method of  claim 38 , wherein said detecting said first resolution signal indicative of said resolution of said first display signal is performed using horizontal and vertical synchronization signals related to said first display signal. 
     
     
       40. The video signal converting method of  claim 39 , wherein said first display signal comprises an analog signal and said second display signal comprises a digital signal. 
     
     
       41. A video signal converting method which is provided to convert a first display signal into a second display signal, said method comprising:
   detecting a first resolution signal indicative of a resolution of said first display signal;        comparing said first resolution signal with a second resolution signal indicative of a reference resolution; and        converting said first display signal having a first resolution into said second display signal having a second resolution without changing the frame rate of the first display signal such that the first display signal and the second display signal have the same frame rate, if said comparing step determines that there is a difference between said first and second resolution signals,        wherein said second resolution is different from said first resolution; and        wherein said video signal converting method is performed in a display apparatus.