Apparatus for converting aspect ratio and number of scanning lines of a video signal

Claim 1

An apparatus for converting aspect ratio and number of scanning lines of a video signal including an input latch 2, a field memory 3 and an output latch 4 which converts the received HDTV video signal having aspect ratio of 16 to 9 and scanning lines above 1050 into a NTSC TV video signal of a zoom-up mode having scanning lines of 525 and aspect ratio of 3 to 4 and a wide mode converting 375 lines in the center of picture screen to maintain aspect ratio of 16 to 9, said apparatus comprising: input control means for controlling said input latch 2 and said field memory 3 to write said HDTV video signal inputted from said input latch 2 into said field memory; said input control means including an HDTV horizontal line start signal generator 6-1 being synchronized by an HDTV clock signal inputting an HDTV frame start signal as count reset signal and outputting the predetermined pulse signal at start of every horizontal line of an HDTV signal; a first address generator 6-2 being reset by the output of said HDTV horizontal address signal; a second address generator 6-3 being reset by said HDTV frame start signal and generating a vertical address signal; an HDTV horizontal control signal generation ROM 6-4 generating each horizontal component of a NTSC TV frame start signal, a field memory write reset signal and a field memory write enable signal by the output of said first address generator 6-2 and a mode select signal; an HDTV vertical control signal generation ROM 6-5 generating each vertical component of a NTSC TV frame start signal, a field memory write reset signal and a field memory write enable signal by the output of said second address generator 6-3 and a mode select signal; first logic means 6-6 generating a NTSC TV frame start signal at start of common portion of the horizontal and vertical components of said NTSC TV frame start signal; second logic means 6-7 generating a field memory write reset signal at start of common portion of the horizontal and vertical components of said field memory write reset signal and applying said signal to said field memory 3; and third logic means 6-8 generating a field memory write enable signal at start of common portion of the horizontal and vertical components of said field memory write enable signal and applying said signal to said field memory 3; output control means for controlling said field memory 3 and said output latch 4 to convert said HDTV video signal written into said field memory 3 into said NTSC TV video signal by selecting plural modes (mode l through mode N) corresponding to aspect ratio and number of scanning lines of the converting video signal; and said output control means including a signal selector 7-1 selecting a read clock for said field memory 3 and a clock for said output latch 4 by a mode select signal; a NTSC TV horizontal line start signal generator 7-2 inputting a NTSC TV frame start signal outputted from said input control means 6 as count reset signal and outputting the predetermined pulse signal at start of every horizontal line of a NTSC TV signal; a third address generator 7-3 being reset by the output of said NTSC TV horizontal line start signal generator 7-2 and generating a horizontal address signal; a fourth address generator 7-4 being reset by said NTSC TV frame start signal and generating a vertical address signal; a NTSC TV horizontal control signal generation ROM 7-5 generating each horizontal component of a field memory read reset signal and a field memory read enable by the output of said third address generator 7-3 and a mode select signal; a NTSC TV vertical control signal generation ROM 7-6 generating each vertical component of a field memory read reset signal and a field memory read enable signal by the output of said fourth address generator 7-4 and a mode select signal; a fourth logic means 7-7 generating a field memory read reset signal at start of common portion of the horizontal and vertical components of said field memory read enable signal and applying said signal to said field memory 3; and fifth logic means 7-8 generating a NTSC TV field memory read enable signal at start of common portion of the horizontal and vertical components of said field memory read enable signal and applying said signal to said field memory 3.

Claim 2

An apparatus for converting aspect ratio and number of scanning lines of a video signal including an input latch 2, a field memory 3 and an output latch 4 which converts the received HDTV video signal having aspect ratio of 16 to 9 and scanning lines above 1050 into a NTSC TV video signal of a zoom-up mode having scanning lines of 525 and aspect ratio of 3 to 4 and a wide mode converting 375 lines in the center of picture screen to maintain aspect ratio of 16 to 9, said apparatus comprising: input control means for controlling said input latch 2 and said field memory 3 to write said HDTV video signal inputted from said input latch 2 into said field memory; said input control means including an HDTV horizontal line start signal generator 6-1 being synchronized by an HDTV clock signal inputting an HDTV frame start signal as count reset signal and outputting the predetermined pulse signal at start of every horizontal line of an HDTV signal; a first address generator 6-2 being reset by the output of said HDTV horizontal address signal; a second address generator 6-3 being reset by said HDTV frame start signal and generating a vertical address signal; an HDTV horizontal control signal generation ROM 6-4 generating each horizontal component of a NTSC TV frame start signal, a field memory write reset signal and a field memory write enable signal by the output of said first address generator 6-2 and a mode select signal; an HDTV vertical control signal generation ROM 6-5 generating each vertical component of a NTSC TV frame start signal, a field memory write reset signal and a field memory write enable signal by the output of said second address generator 6-3 and a mode select signal; first logic means 6-6 generating a NTSC TV frame start signal at start of common portion of the horizontal and vertical components of said NTSC TV frame start signal; second logic means 6-7 generating a field memory write reset signal at start of common portion of the horizontal and vertical components of said field memory write reset signal and applying said signal to said field memory 3; and third logic means 6-8 generating a field memory write enable signal at start of common portion of the horizontal and vertical components of said field memory write enable signal and applying said signal to said field memory 3; output control means for controlling said field memory 3 and said output latch 4 to convert said HDTV video signal written into said field memory 3 into said NTSC TV video signal by selecting plural modes (mode l through mode N) corresponding to aspect ratio and number of scanning lines of the converting video signal; and said output control means including a signal selector 7-1 selecting a read clock for said field memory 3 and a clock for said output latch 4 by a mode select signal; a NTSC TV horizontal line start signal generator 7-2 inputting a NTSC TV frame start signal outputted from said input control means 6 as count reset signal and outputting the predetermined pulse signal at start of every horizontal line of a NTSC TV signal; a third address generator 7-3 being reset by the output of said NTSC TV horizontal line start signal generator 7-2 and generating a horizontal address signal; a fourth address generator 7-4 being reset by said NTSC TV frame start signal and generating a vertical address signal; a NTSC TV horizontal control signal generation ROM 7-5 generating each horizontal component of a field memory read reset signal and a field memory read enable by the output of said third address generator 7-3 and a mode select signal; a NTSC TV vertical control signal generation ROM 7-6 generating each vertical component of a field memory read reset signal and a field memory read enable signal by the output of said fourth address generator 7-4 and a mode select signal; a fourth logic means 7-7 generating a field memory read reset signal at start of common portion of the horizontal and vertical components of said field memory read enable signal and applying said signal to said field memory 3; and fifth logic means 7-8 generating a NTSC TV field memory read enable signal at start of common portion of the horizontal and vertical components of said field memory read enable signal and applying said signal to said field memory 3.