Video signal conversion method for displaying a 4:3 video signal on a 16:9 screen

Abstract

The present invention provides a video signal conversion method for displaying a video signal having a 4:3 aspect ratio on a screen having a 16:9 aspect ratio by using a single clock. The video signal conversion comprises the steps of inserting two zero pixels between two pixels of the 4:3 video signal, .[.band.]. .Iadd.low .Iaddend.pass filtering the two pixels of the 4:3 video signal, such that .[.3/4 of the bandwidth of the pixels is passed and upper and lower parts of pixels are not passed,.]. .Iadd.the 3/4 band of the upper part and the lower part of the spectrum are respectively passed, .Iaddend.and sampling the filtered pixels by every fourth transition of a clock signal, and then displaying the sampled pixels on the 16:9 screen.

What is claimed is: 
     
       1. A video signal conversion method for displaying a 4:3 video signal having an aspect ratio of 4:3, on a 16:9 screen having an aspect ratio of 16:9, said method comprising the steps of: inserting zero pixels between a first and second pixel of the 4:3 video signal;   .[.band.]. .Iadd.low .Iaddend.pass filtering said first and second pixel;   sampling the filtered pixels every fourth transition of a clock signal; and   displaying the sampled pixels on the 16:9 screen.   
     
     
       2. The video signal conversion method as claimed in claim 1, wherein said .[.band.]. .Iadd.low .Iaddend.pass filtering step .[.passes a bandwidth such that an upper portion and a lower portion of the frequency spectrum of each pixel is not passed.]. .Iadd.causes a 3/4 band of an upper part and a lower part of the frequency spectrum of each of said first and second pixels to be passed.Iaddend.. 
     
     
       3. The video signal conversion method as claimed in claim 2, wherein said .[.band.]. .Iadd.low .Iaddend.pass filtering step passes a bandwidth 3/4 B, wherein one pixel of 4:3 video signal has a bandwidth of 2 B. 
     
     
       4. The video signal conversion method as claimed in claim 1, wherein two zero pixels are inserted. 
     
     
       5. The video signal conversion method as claimed in claim 4, wherein the insertion of two zero pixels is accomplished by multiplying the sampling frequency of the pixels of said 4:3 video signal by 1/3. 
     
     
       6. The video signal conversion method as claimed in claim 1, wherein said .[.band.]. .Iadd.low .Iaddend.pass filtering is accomplished by multiplying the pixels between which the zero pixels are inserted, by 13 filter taps of a filter. 
     
     
       7. The video signal conversion method as claimed in claim 1, wherein the pixels sampled by every fourth transition of the clock are displayed on a center of the 16:9 screen. 
     
     
       8. The video signal conversion method as claimed in claim 1, wherein the pixels sampled by every fourth transition of a clock are displayed on a side of the 16:9 screen. 
     
     
       9. A video signal conversion apparatus for displaying a 4:3 video signal having an aspect ratio of 4:3, on a 16:9 screen having an aspect ratio of 16:9, said apparatus comprising: a zero inserter for inserting zero pixels between a first and second pixel of the 4:3 video signal;   a .[.band.]. .Iadd.low .Iaddend.pass filter for .[.band.]. .Iadd.low .Iaddend.pass filtering the first and second pixel having zero pixels inserted therebetween;   a single clock signal;   a sub-sampler for sampling the filtered pixels by every fourth transition of the clock signal; and   a controller for displaying the sampled pixels on the 16:9 screen.   
     
     
       10. The video signal conversion apparatus as claimed in claim 9, wherein said .[.band.]. .Iadd.low .Iaddend.pass filter .[.passes a bandwidth such that an upper portion and a lower portion of the frequency spectrum of each pixel is not passed.]. .Iadd.causes a 3/4 band of an upper part and a lower part of the frequency spectrum of each of said first and second pixels to be passed.Iaddend.. 
     
     
       11. The video signal conversion apparatus as claimed in claim 10, wherein said .[.band.]. .Iadd.low .Iaddend.pass filter passes a bandwidth 3/4 B, wherein one pixel of 4:3 video signal has a bandwidth of 2 B. 
     
     
       12. The video signal conversion apparatus as claimed in claim 9, wherein the zero pixel inserter inserts two zero pixels. 
     
     
       13. The video signal conversion apparatus as claimed in claim 12, wherein the zero inserter inserts two zero pixels by multiplying the sampling frequency of the pixels of said 4:3 video signal by 1/3. 
     
     
       14. The video signal conversion apparatus as claimed in claim 9, wherein said .[.band.]. .Iadd.low .Iaddend.pass filter comprises a filter having 13 taps, said .[.band.]. .Iadd.low .Iaddend.pass filter multiplying the pixels between which the zero pixels are inserted, by the 13 filter taps. 
     
     
       15. The video signal conversion apparatus as claimed in claim 9, wherein said controller displays the pixels sampled by every fourth transition of a clock on a center of the 16:9 screen. 
     
     
       16. The video signal conversion apparatus as claimed in claim 9, wherein said timing controller displays the pixels sampled by every fourth transition of a clock on a side of the 16:9 screen.