Motion video signal processing for recording or reproducing – Local trick play processing – With randomly accessible medium
Reexamination Certificate
1997-07-31
2001-03-20
Garber, Wendy (Department: 2615)
Motion video signal processing for recording or reproducing
Local trick play processing
With randomly accessible medium
C348S555000, C348S556000, C348S459000, C386S349000
Reexamination Certificate
active
06205288
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus and method for reproducing a video signal according to a video signal recording mode of a digital video disk and a television mode, and more particularly, to an apparatus and method for reproducing a video signal recorded by an NTSC (National Television System Committee) system in a disk according to a pseudo PAL (Phase Alternation by Line) system.
2. Description of the Related Art
A pseudo PAL system represents that only horizontal and vertical synchronization signals of a PAL system are changed to an NTSC system. The pseudo PAL system is used when trying to watch a video signal of the NTSC system by use of a television of the PAL system. Generally, the PAL system is different from the NTSC system in that one of I and Q signals is phase-shifted every scanning line when transmitted.
FIG. 1
illustrates a conventional pseudo PAL video signal reproducing apparatus. A YC separator
10
separates an analog composite video signal S
1
of the NTSC system provided from a video source into a luminance signal Y and a color difference signal C. A color difference signal separator
20
separates the luminance signal Y and the color difference signal C into signals Y, R-Y and B-Y and a video synchronization signal sync on the basis of a chrominance signal frequency of 3.58 MHz. A video encoder
30
receives the signals Y, R-Y and B-Y and the video synchronization signal sync and generates a pseudo PAL video signal S
2
based on a PAL system chrominance signal frequency of 4.43 MHz.
However, if the video signal is again mixed after it is separated into the signals Y, R-Y and B-Y, a part of the top and bottom of a screen becomes black and an aspect ratio of the entire screen varies. In other words, picture quality is degraded. Furthermore, circuit configurations are very complicated and a large number of variable components is needed, thereby lowering productivity.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an apparatus and control method for preventing picture quality from deteriorating and simplifying circuit configurations so as not to use variable components when reproducing a video signal recorded by an NTSC system according to a pseudo PAL system.
It is another object of the invention to provide an apparatus and control method which can adaptively reproduce a video signal suitable for a television mode without degrading picture quality or without using variable components when a video signal recording mode is different from the TV mode.
The present invention includes a pseudo PAL video signal reproducing apparatus for reproducing information from a digital video disk and transferring a reproduced signal to a television. One embodiment of the pseudo PAL video signal reproducing apparatus includes an MPEG video decoder for generating digital video data by decoding an MPEG data stream reproduced from the disk in synchronization with a video clock supplied from the exterior and generating a PAL or NTSC video synchronization signal according to a select signal, a video processor for converting the digital video data to an analog video signal and generating a PAL or NTSC chrominance signal frequency according to the select signal, a key input section for selecting a television mode which is to provide a video signal reproduced from the disk in a PAL or NTSC mode, and a controller for selecting the MPEG video decoder and the video processor in the PAL or NTSC mode according to the television mode select information supplied from the key input section and disk information reproduced from the disk.
The present invention also includes a method for reproducing a pseudo PAL video signal in a digital video disk reproducing apparatus having an MPEG video decoder and a video processor. In one embodiment, the method includes the steps of checking a television mode, if the television mode is a PAL system, selecting the video processor in a PAL mode and checking a video signal mode recorded in the disk, and if the video signal recording mode is an NTSC system, selecting the video decoder as an NTSC mode so as to supply the pseudo PAL video signal to the television.
These and other objects, features and advantages of the invention will be further described and more readily apparent from a review of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings. In the following description, numerous specific details are set forth to provide a more thorough understanding of the invention. It will be apparent, however, to one skilled in the art, that the invention may be practiced without these specific details. In other instances, well known features and constructions are not described so as not to obscure the invention.
REFERENCES:
patent: 5005077 (1991-04-01), Samad et al.
patent: 5229853 (1993-07-01), Myers
patent: 5255091 (1993-10-01), Lyon et al.
patent: 5457499 (1995-10-01), Lim
patent: 5504532 (1996-04-01), Rhodes
patent: 5530484 (1996-06-01), Bhatt et al.
patent: 5631710 (1997-05-01), Kamogawa et al.
patent: 5734435 (1998-03-01), Wilson et al.
Boccio Vincent F.
Garber Wendy
Samsung Electronics Co,. Ltd.
Staas & Halsey , LLP
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