Television – Image signal processing circuitry specific to television – Gray scale transformation
Reexamination Certificate
1998-09-21
2001-09-11
Eisenzopf, Reinhard J. (Department: 2614)
Television
Image signal processing circuitry specific to television
Gray scale transformation
C348S678000, C348S712000, C382S274000
Reexamination Certificate
active
06288755
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a signal processing apparatus, and in particular, to a video signal processing apparatus.
2. Background of the Related Art
As shown in
FIG. 1
, a related art video signal processing apparatus is provided with a luminance signal processing unit
1
for controlling a picture status (brightness, contrast and the like) with regard to a luminance signal Y. The luminance signal Y is separated from a composite video signal in accordance with a video control signal VC.
The luminance signal processing unit
1
is connected between a video signal separating unit (not shown) for separating luminance signal Y from the composite video signal, which is outputted via an antenna and a tuner, and a matrix (not shown) for separating primary color signals R, G, B from the luminance signal Y. The video control signal VC serves to control a contrast and a brightness with regard to video signals.
The operation of the related art video signal processing apparatus will now be described. First, the video signal separating unit (not shown) separates luminance signal Y from the composite video signal received through the antenna and the tuner. The video control signal VC for controlling brightness and contrast of a screen picture is outputted from a microprocessor (not shown). The luminance signal processing unit
1
automatically controls and outputs to the matrix (not shown) a picture status (brightness, contrast and the like) with regard to a luminance signal Y separated from a composite video signal in accordance with video control signal VC. The controlled luminance signal is separated by the matrix (not shown) into the primary color signals R, G, B, which are then displayed on the picture screen.
The related art video signal processing apparatus has various disadvantages. When the luminance signal Y has a high frequency band, a large black/white comparison, and experiences a contrast processing in the luminance signal processing unit
1
, a black/white comparison degree in the high frequency band may be relatively larger than other frequency bands. As a result, when the luminance signal Y is displayed on a picture screen, the high frequency band can cause a screen flickering phenomenon because of the relatively larger black/white comparison.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a video signal processing apparatus that substantially obviates at least one of problems or disadvantages of the related art.
Another object of the present invention to provide a video signal processing apparatus that reduces or removes a picture screen flicker.
An object of the present invention is to provide a video signal processing apparatus that reduces a flickering phenomenon caused by a radio frequency band that enlarges a black/white comparison.
An object of the present invention is to provide a video signal processing apparatus that reduces flicker caused by a high frequency band increasing a black/white comparison by relatively decreasing a black/white comparison processing degree with regard to a detected high frequency band in a luminance signal.
To achieve at least the above-described objects in a whole or in parts, there is provided a video signal processing apparatus according to the present invention that includes a gate pulse generator for detecting a high frequency band in accordance with a luminance signal Y separated from a composite video signal and outputting a gate pulse signal, and a luminance signal processing unit for adjusting a contrast with regard to a high frequency band in the luminance signal Y in accordance with the gate pulse signal outputted from the gate pulse generator.
To further achieve the above objects in a whole or in parts, a video signal processing apparatus includes high and low level slicing units that divide a luminance signal into first and second level signals, wherein the first level signal is higher than the second level signal, first and second high frequency detectors that detect first and second high frequency bands respectively using the first and second level signals, a logic circuit that logically processes the first and second high frequency bands from the first and second detectors and determines a prescribed frequency band, and a luminance signal processing unit that reduces a contrast of the luminance signal within the prescribed frequency band relative to the luminance signal outside the prescribed frequency band.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.
REFERENCES:
patent: 4768095 (1988-08-01), Wada et al.
patent: 4774580 (1988-09-01), Miyasako
patent: 4812905 (1989-03-01), Rossi
patent: 5041904 (1991-08-01), Higuchi et al.
patent: 5638138 (1997-06-01), Hickman
patent: 5673355 (1997-09-01), Strolle et al.
patent: 5867228 (1999-02-01), Miki et al.
Eisenzopf Reinhard J.
Fleshner & Kim LLP
Hyundai Electronics Industries Co,. Ltd.
Tran Trang U.
LandOfFree
Video signal processing apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Video signal processing apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Video signal processing apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2501890