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June 30, 1997

Self-contained "Progressive LSI" Developed by Hitachi for High Picture Quality Signal Conversion

- Universal application is possible for broad range of display devices from TVs to plasma displays with high picture quality motion picture -

Motion picture infrastructures are undergoing major changes, in converting from analog to digital format, spurred by the start of data broadcasting, digital satellite broadcasting, and the increased penetration of PCs into ordinary households. The proliferation of video signal formats is generating a demand for display devices that can handle high-definition resolutions and PC display formats as well as NTSC. At the same time, the development of display devices requires the appropriate signal conversion technology to match those of fixed-pixel displays such as LCDs and plasma displays.

The Progressive LSI can convert a standard NTSC interlaced-scanning(*) TV signal into a progressive-scanning(**) signal, using subsampling motion adaptive scanning interpolation(***) technology, which produces high picture quality. The Progressive LSI offers a high level of format cross-conversion flexibility that enables outputs to be matched to display device capabilities. An NTSC TV signal, for example, can be displayed on a PC screen, or a high-definition signal or a PC video signal such as VGA or SVGA can be displayed on a standard CRT, LCD or plasma display.

The chip has a scaling function that enables the size of a picture to be varied from x1/5 to x256, horizontally and vertically, and moved to any position. It also features an adaptive enhancer function that emphasizes the outline of screen images according to the scaling ratio, thus making the picture seem more real.

Hitachi will incorporate this key device for the multimedia age in, first of all, a wide-screen TV to be released this fall, then in liquid-crystal and plasma display products to follow.

*Interlaced scanning
The scanning frame (the TV picture) consists of two scanning fields. The lines of the first field are scanned so that an equal empty space is maintained between lines. The lines of the following, second, field are laid down in the spaces between the lines of the first field. This process is termed interlaced scanning. The frame scanning rate is 30 frames per second.

**Progressive scanning
(A standard widely used in PC monitor display.) Each picture (frame) is formed by 525 subsequent scanning lines in 1/ 60 second.

***Subsampling motion adaptive scanning interpolation
Conventional motion adaptive scanning interpolation converts an interlaced scanning TV signal to a progressive scanning signal, with interpolation from the preceding field signal in still pictures, while the preceding and subsequent lines in current field are used for interpolation of moving portions.

Subsampling motion adaptive scanning interpolation utilizes both the preceding field signal and the current field signal for still pictures, which minimizes picture quality degradation caused by the conventional systems and halves the required memory capacity.

Specifications of Progressive LSI

1.	TV signal processing	Motion adaptive scanning line interpolation by subsampling
2.	Input format	Y/chroma difference (4:2:2)
3.	Input signal	TV:NTSC, high-definition TV, PAL 13.5 MHz digital (ITU-R601 standard) PC:VGA, SVGA, XGA (simple display)
4.	Output signal	TV:525 P, 1125 i, 625P PC:VGA, SVGA, XGA
5.	Output format	Y/chroma difference (digital), RGB (digital)
6.	Scaling range	Horizontal: x1/5 - x256 Vertical: x1/5 - x256
7.	Picture setting	Enlargement ratio adaptive enhancer (horizontal and vertical
8.	Other	AC/DC converter incorporated
9.	Application	Color TV, high-definition TV, Monitor display, fixed-pixel display (PDP, LCD, LCD projector, etc.)

VGA and XGA are registered trademarks of International Business Machines Corporation.

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