Meridian Audio LD100/LD100U manual

on two different mechanisms. Horizontal resolution is a function of bandwidth (frequency response) of the circuitry while vertical resolution is a function of the scanning fre- quency (the number of scan lines in each picture). Given these mechanisms and the average size picture tube being 8-10”, they designed the 525 line broadcast stan- dard so that viewers would not see the scan lines when watching TV. They had no idea that someday people would be projecting home theater video images with diag- onal screen sizes of 10’ and more.

Based on those NTSC parameters, using a 10 ft. diagonal screen, would require the viewer to be located more than 45 ft. from the screen to see the picture as it was intend- ed, without scan lines! Unfortunately, today’s large screen installations have scan lines that are quite visible, espe- cially with some of the latest high resolution monitors and projection televisions. The LD100 eliminates this problem by scan doubling, or digitally doubling the 525 lines to become 1050 lines. The result is the elimination of visible scan lines. The image produced by the LD100 is clearer, continuous and virtually film-like.

SECTION C – The LD100 Bandwidth Expansion Circuitry: SHARPENING OF THE IMAGE DETAILS – There is a major limitation with most contemporary NTSC program sources — lack of frequency response. The best video sources such as satellite dish reception and laserdiscs can provide acceptable resolution (400 plus lines of hori- zontal resolution). Other more common sources however, such as VHS tapes (230 lines), are clearly deficient. The problem is compounded when one doubles the scan lines and performs other signal processing. The lack of high frequency detail becomes very obvious with almost all

sources. The resultant picture is free of scan lines but dull, with a serious loss of definition. The solution is to expand the high frequencies without producing annoying and pic- ture degrading artifacts.

The bandwith expansion circuitry in the LD100 is excep- tionally sophisticated, using Faroudja’s double differentia- tion techniques to sharpen the edges of both horizontal and vertical details. The result is a sharply detailed line doubled image that appears crisp and three dimensional with no visible negative side-effects. This process can effectively double the bandwidth and therefore the resolu- tion of the incoming signal.

FAROUDJA LD100 APPLICATIONS – While the techni- cal accomplishments of the LD100 represent years of intense research and development, its use is straightfor- ward and direct. The block diagram (above), illustrates a typical home theater system configuration and shows how the LD100 would be inserted in the signal path. Many entertainment sources benefit greatly by the LD100’s unique attributes; laserdisc, VHS video, S-VHS video, cable TV, broadcast TV, etc. The LD100 has proven to be an invaluable tool in other presentation disciplines where image quality is important – computer data displays, pro- fessional installations in boardrooms and media rooms, military installations, government agencies and academic uses in schools and colleges. From the quality of its indi- vidual parts to its state-of-the-art patented circuitry, the LD100 is truly in a class by itself. There is simply no finer video processor available . . . at any price!

NOTE: The LD100 (NTSC only version) operates properly with 50Hz 625 line component or RGB sources.

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