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Article #14553Re: Are TV's interlaced? Why no flicker?
From: BARR DOUG
Date: Mon, 16 Nov 1992 15:45
Date: Mon, 16 Nov 1992 15:45
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In article <1992Nov14.032849.11189@ultb.isc.rit.edu> jdc3538@ultb.isc.rit.edu (J.D. Cronin) writes: > >Why don't ordinary TV sets flicker? A friend told me that standard >NTSC video signals are interlaced. That doesn't make sense, since >the picture should flicker enough to be unwatchable. > >Any ideas on what's going on here? > >Jim NTSC color television is the standard for North America, Japan and a few other countries. 30 frames (or pictures) are recieved a second. However, these frames are displayed by using 2:1 interlacing - 2 scans for each complete frame. The first scan illuminates the odd rows, the 2nd scan illuminates the even rows. This reduces flicker. By the way, interlacing in computer displays with computer graphic images can introduce strange and unwanted interference patterns.
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Newsgroups: sci.electronics Path: arc1-ca.pugleaf.net!sparky!uunet!boulder!ucsu!tramp.Colorado.EDU!barr From: barr@tramp.Colorado.EDU (BARR DOUG) Subject: Re: Are TV's interlaced? Why no flicker? Message-ID: <1992Nov16.154556.18027@ucsu.Colorado.EDU> Sender: news@ucsu.Colorado.EDU (USENET News System) Nntp-Posting-Host: tramp.colorado.edu Organization: University of Colorado, Boulder References: <1992Nov14.032849.11189@ultb.isc.rit.edu> Distribution: na Date: Mon, 16 Nov 1992 15:45:56 GMT Lines: 18