Abstract: A video signal compression apparatus extracts a specific value written in a read only memory at every system clock pulse. The specific value can be varied at every clock pulse. Therefore, for example, only the center part of a picture can be horizontally compressed. A FIFO memory may be used. It is possible to select a mode with a fixed compression ratio or a mode in which a compression ratio varies at every clock pulse. Further, the fixed compression ratio can be set from the outside. Display position of the picture can also be changed.

Abstract: A video signal processing apparatus processes plural kinds of video signals and is used for displaying each one of the processed outputs of the plural kinds of video signals on the same screen. In the video signal processing apparatus, a memory used for a subtitle processing circuit and a memory used for a helper signal separation circuit are used in common by providing a switching means to switch according to an input video signal. A subtitle processing circuit magnifies a video signal with a letter box format such that a horizontally long picture is inserted in a picture with a 4:3 aspect ratio on a horizontally long screen with 2:1 or 16:9 aspect ratio. The helper signal separation circuit is used for receiving a television signal such as an EDTV 2 system which has a helper signal to improve picture quality.

Abstract: The object of the present invention is to use signal decoding circuits for a first generation EDTV signal and a second generation EDTV signal in common and to suppress an increase of circuit scale.An EDTV signal decoding apparatus of the present invention is constructed with a cascade connection of a first A/D converter, a first signal processing circuit, a first D/A converter, a second A/D converter, a second signal processing circuit and a second D/A converter. The first group composed of the first A/D converter, the first signal processing circuit and the first D/A converter are driven by a clock signal synchronizing with a color burst signal. The second group composed of the second A/D converter, the second signal processing circuit and the second D/A converter are driven by a clock signal synchronizing with a horizontal sync signal.

Abstract: The present invention sequentially selects and outputs one of a plurality of video image sources 1 by an image signal source switching means 2, processes the video images by thinning circuit portions 3 and 4, writes in the video data into an image memory 5 and display the images on an image display device 6. Depending upon the detection output of an aspect ratio detecting circuit portion 12, which detects an aspect ratio of an image display of each of the video image source 1, thinning ratios of the thinning circuits 3 and 4 and a write in control circuit portion 9 for the image memory are switched in order to obtain a multiscreen display circuit which can display video signal sources having different aspect ratios.

Abstract: In an image display apparatus including a display unit for displaying an image of an inputted video signal thereon with a predetermined field frequency and a predetermined number of scanning lines using vertical and horizontal synchronizing signals for deflection of display in response to the inputted video signal, a first converter converts an inputted first video signal having a first field frequency which is lower than the predetermined field frequency and having the predetermined number of scanning lines, into an output second video signal having the predetermined field frequency and the predetermined number of scanning lines, and outputs the output second video signal to the display unit.

Abstract: In an image display apparatus including a display unit for displaying an image of an inputted video signal thereon with a predetermined field frequency and a predetermined number of scanning lines using vertical and horizontal synchronizing signals for deflection of display in response to the inputted video signal, a first converter converts an inputted first video signal, having a first field frequency which is lower than the predetermined field frequency and having the predetermined number of scanning lines, into an output second video signal having the predetermined field frequency which is and the predetermined number of scanning lines, and having outputs the output second video signal to the display unit.