Video signal converting apparatus and a 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 horizonal 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 display apparatus capable of converting a first display signal into a second display signal comprising:
   a screen capable of displaying a video signal, said screen having a predetermined resolution;        a detector which detects a first resolution signal of said first display signal, wherein the first resolution signal is a horizontal synchronization signal and a vertical synchronization signal;        a comparator which compares said first resolution signal with said predetermined resolution; and        a converter which converts said first display signal having a first resolution and a first frame rate into said second display signal having said predetermined resolution and a second frame rate if said comparator determines that said predetermined resolution is greater than said first resolution;        wherein said second frame rate is the same as said first frame rate.     
     
     
       12. The display apparatus of  claim 11 , wherein said second frame rate is always the same as said first frame rate. 
     
     
       13. A display apparatus capable of converting a first display signal into a second display signal comprising:
   a screen capable of displaying a video signal, said screen having a predetermined resolution;        a detector which detects a first resolution signal of said first display signal, wherein the first resolution signal is a horizontal synchronization signal and a vertical synchronization signal; and        a converter which converts said first display signal having a first resolution and a first frame rate into said second display signal having said predetermined resolution and a second frame rate if said predetermined resolution is greater than said first resolution;        wherein said second frame rate is always the same as said first frame rate.     
     
     
       14. A display apparatus capable of converting a first display signal into a second display signal comprising:
   a screen capable of displaying a video signal, said screen having a predetermined resolution;        a detector which detects a first resolution signal of said first display signal, wherein the first resolution signal is a horizontal synchronization signal and a vertical synchronization signal; and        a converter which converts said first display signal having a first resolution and a first frame rate into said second display signal having said predetermined resolution and a second frame rate;        wherein said second frame rate is always the same as said first frame rate.     
     
     
       15. The display apparatus of  claim 14  further comprising a means for comparing said first resolution with said predetermined resolution,
   wherein the converter converts said first display signal having said first resolution and said first frame rate into said second display signal having said predetermined resolution and said second frame rate if said means for comparing determines that said predetermined resolution is greater than said first resolution.     
     
     
       16. The display apparatus of  claim 14  further comprising a means for generating a first signal, said means for generating the first signal receiving the first resolution and generating said first signal in accordance with a predetermined criterion,
   wherein the converter converts said first display signal having said first resolution and said first frame rate into said second display signal having said predetermined resolution and said second frame rate in accordance with said first signal.     
     
     
       17. The display apparatus of  claim 16 , wherein the predetermined criterion is a predetermined resolution. 
     
     
       18. The display apparatus of  claim 16 , wherein the predetermined criterion is whether a predetermined resolution is greater than said first resolution. 
     
     
       19. 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, wherein the first resolution signal is a horizontal synchronization signal of the first display signal and a vertical synchronization signal of the first display signal; and        converting said first display signal having a first resolution and a first frame rate into a second display signal having a second resolution corresponding to a reference resolution and a second frame rate if the first resolution is different from the second resolution,        wherein the first display signal is a computer signal;        wherein said second frame rate is the same as said first frame rate; and        wherein said video signal converting method is performed in a computer monitor.     
     
     
       20. The video signal converting method of  claim 19 , wherein the second frame rate is always the same as the first frame rate. 
     
     
       21. The video signal converting method of  claim 19  further comprising comparing said first resolution with said second resolution,
   wherein the second frame rate is always the same as the first frame rate.